STRATIGRAPHY, SEDIMENTOLOGY, AND TIDAL PROCESSES OF THE LATE MIOCENE TO EARLY PLIOCENE SOUTHERN BOUSE FORMATION, SOUTHEAST PALO VERDE MOUNTAINS, CALIFORNIA by KEVIN KORTUM GARDNER A THESIS Presented to the Department of Earth Sciences and the Graduate School of the University of Oregon in partial fulfillment of the requirements for the degree of Master of Science September 2019 THESIS APPROVAL PAGE Student: Kevin Kortum Gardner Title: Stratigraphy, Sedimentology, and Tidal Processes of the Late Miocene to Early Pliocene Southern Bouse Formation, Southeast Palo Verde Mountains, California This thesis has been accepted and approved in partial fulfillment of the requirements for the Master of Science degree in the Department of Earth Sciences by: Dr. Rebecca J.Dorsey Advisor Dr. Marli Miller Chair Dr. Gregory Retallack Member and Janet Woodruff-Borden Vice Provost and Dean of the Graduate School Original approval signatures are on file with the University of Oregon Graduate School. Degree awarded September 2019 ii © 2019 Kevin Kortum Gardner iii THESIS ABSTRACT Kevin Kortum Gardner Master of Science Department of Earth Sciences September 2019 Title: Stratigraphy, Sedimentology, and Tidal Processes of the Late Miocene to Early Pliocene Southern Bouse Formation, Southeast Palo Verde Mountains, California Contrasting hypotheses for the depositional paleoenvironments of the late Miocene to early Pliocene southern Bouse Formation currently hinder progress toward a consensus on tectonic and paleogeographic reconstructions for the lower Colorado River region. The basal carbonate member of the southern Bouse Formation has been interpreted to record deposition in either (i) a large inland lake isolated from the ocean, or (ii) a transgressive intertidal to subtidal marine seaway. In this study, we analyze sedimentary lithofacies, facies associations, paleocurrents, and architecture of large-scale compound bedforms to develop a comprehensive depositional model. Our paleocurrent data and analyses of bedform architecture and facies association support a tidal origin for the southern Bouse Formation. Our paleogeographic reconstruction constrains the location of marine connection required by paleontological and sedimentary data. Our interpretation provides strong evidence in favor of a tidal origin and requires post-Miocene regional uplift. This paper includes unpublished, coauthored material. iv CURRICULUM VITAE NAME OF AUTHOR: Kevin Kortum Gardner GRADUATE AND UNDERGRADUATE SCHOOLS ATTENDED: University of Oregon, Eugene Whitman College, Walla Walla DEGREES AWARDED: Master of Science, Geological Sciences, 2019 University of Oregon Bachelor of Arts, Geology, 2016, Whitman College AREAS OF SPECIAL INTEREST: Analytical Process Sedimentology Stratigraphy Basin Analysis Structural Geology Geologic Mapping PROFESSIONAL EXPERIENCE: Graduate Teaching Fellow, University of Oregon, 2017-2019 Undergraduate Researcher, Keck Geology Consortium, 2015 GRANTS, AWARDS, AND HONORS: Outstanding Teaching Assistant Award, University of Oregon, 2019 Graduate Student Research Grant, Geological Society of America, 2018 Dr. Albert R. Leeds Prize for Excellence in Geology, Whitman College, 2016 v ACKNOWLEDGMENTS I wish to express the utmost appreciation for my advisor Becky Dorsey for providing funding for this research and for consistent support of my work through thoughtful discussion and review. Under your guidance I have learned to be a better geologist, to integrate observations both large and small, create unique solutions to unique problems, and to strive towards excellence in science. Your enthusiasm for geology is second to none, and it has been an exciting journey with you. I would also like to thank my committee members Marli Miller and Gregory Retallack for their thoughtful feedback and their review of my work. I would like to express thanks to my field assistants Anthony Downey, Patrick Nonte, and Stephen Wainwright. Your company and support over four wild months in the desert made much of this work possible. From finding a dead body or climbing Palo Verde Peak to eating Albertacos and rock-hunting with desert folk; you all have made my field work the adventure of a lifetime. I would also like to thank Imperial County Sheriff’s Department and Coroner for their timely 2.5 hour response time to finding human remains. An additional thanks goes out to Dave and Ski. Thank you for the generosity, kindness, and friendship you extended towards me while researching near your home. I would like to thank the University of Oregon Department of Earth Sciences, National Science Foundation, and Geological Society of America for financial support. I want to acknowledge the following very special people; Renee and Stephen Gardner for always encouraging me to follow my heart, be curious and do my best; Sophia Cromartie for being my partner, best friend, joy bring, and for listening to me ramble on vi about rocks and graduate school for probably countless hours. You are amazing; James Hogan for being a fantastic friend, a source of interesting conversation, and my brewery buddy; Brennah McVey for your friendship and hospitality throughout school; Josh W and Tyler for your humor, and awesome cookouts; Larry Lai for being a peer mentor. Your advice was invaluable. I know you will do great things!; Michelle and Anne for being excellent office mates. Finally, I want to acknowledge how amazing the earth is. It is an absolute privilege to be able to learn about how its various systems work. The earth and all its life are beautiful beyond compare. I will treasure it for the rest of my life and teach others to do so. vii TABLE OF CONTENTS Chapter Page I. INTRODUCTION .......................................................................................................... 1 II. STRATIGRAPHY, SEDIMENTOLOGY, AND TIDAL PROCESSES OF THE LATE MIOCENE TO EARLY PLIOCENE SOUTHERN BOUSE FORMATION, SOUTHEAST PALO VERDE MOUNTAINS, CALIFORNIA ....................................... 3 Introduction .................................................................................................................. 3 Geologic Background .................................................................................................. 5 Summary of Models for the Bouse Formation ...................................................... 5 Stratigraphic Framework ....................................................................................... 8 Comparison of Lacustrine versus Tidal Sedimentation ............................................. 10 Methods ..................................................................................................................... 16 Sedimentary Lithofacies Analysis ............................................................................. 17 Siliciclastic-Dominant Facies .............................................................................. 17 Carbonate-Dominant Facies ................................................................................ 21 Facies Associations .............................................................................................. 24 Alluvial Fan Facies Association (FA1) ......................................................... 24 Tidally-Influenced Fan Margin Facies Association (FA2) ............................ 27 Tidal Dune Field Facies Association (FA3) .................................................. 31 Sedimentary Bedform Analysis ....................................................................................... 33 Compound Dune Architecture ............................................................................. 34 Paleocurrents and Bedform Thickness ................................................................ 37 Water Depth Estimates from Compound Dune Thicknesses ............................... 38 viii Chapter Page Depositional Model and Buzzards Peak Localities ......................................................... 41 Depositional Model ............................................................................................. 41 Buzzard’s Peak Bouse Localities ......................................................................... 43 Discussion ........................................................................................................................ 45 Lacustrine Depositional Processes............................................................................. 46 Tidal Versus Lacustrine Origin.................................................................................. 48 Paleogeographic Reconstruction................................................................................ 50 Ebb/Flood Dominance and Asymmetry .................................................................... 53 Conclusions...................................................................................................................... 55 Appendix A. List of Measured Sections .......................................................................... 58 Appendix B. Measured Sections ...................................................................................... 60 Appendix C. Petroglyph Park Paleocurrent Data .......................................................... 100 Appendix D. Stallard Area Paleocurrent Data ............................................................... 106 Appendix E. Bedding Measurements ............................................................................ 112 REFERENCES CITED ................................................................................................. 122 ix LIST OF FIGURES Figure Page 1. Map of SE California along lower Colorado River Corridor. ..................................... 4 2. Geologic map of the southern Blythe Basin Compiled from Sherrod and Tosdal, 1991; Richard, 1993; Ricketts et al., 2011; Gootee et al., 2016; this study). Inferred paleodam from Spencer (2013). .................................................................... 6 3. Generalized stratigraphy of the southern Bouse Formation in the southeastern Palo Verde Mountains ................................................................................................. 8 4. Geologic map of the southeastern Palo Verde Mountains, California showing the major units in the region. ....................................................................... 11 5. Schematic diagram of A) tidal dunes and B) tidal bars showin the relationship Between bedform geometry, flow depth, current direction, and accretion direction ..................................................................................................................... 14 6. Fundamental architectural components of a tidal compound dune and their relation to bedform migration and current direction. ................................................. 15 7. Field photos of siliciclastic dominant facies .............................................................. 19 8. Field photos of carbonate dominant facies ................................................................ 22 9. Field photos of the Alluvial Fan Facies Association ................................................. 26 10. Field photos of the bioclastic unit facies Associations .............................................. 28 11. Representative measured sections of the tidally-influenced fan margin facies association .................................................................................................................. 29 12. Representative measured sections of the tidal dune field facies association ............. 32 13. Compound dunes in Petroglyph Park ........................................................................ 35 14. Compound dunes in the Stallard Area ....................................................................... 36 15. Schematic model for the deposition of the basal carbonate member in an ebb- Dominated tidal seaway. ............................................................................................ 42 x Figure Page 16. Photos of mixed carbonate-siliciclastic tidal facies in the Bouse Formation basal carbonate member near Buzzards Peak ............................................................ 44 17. Paleogeographic reconstruction of the tidal seaway in which the basal carbonate member accumulated ................................................................................ 51 xi LIST OF TABLES Table Page 1. Lithofacies ................................................................................................................. 20 2. Facies Associations .................................................................................................... 25 3. Compound Dune Thicknesses and Water Depth Estimates....................................... 40 xii CHAPTER I INTRODUCTION The late Miocene to early Pliocene Bouse formation is exposed discontinuously along the margins of the lower Colorado River corridor. The three members: (1) basal carbonate, (2) siliciclastic, and (3) upper bioclastic record the conditions prior to and throughout the first integration of the Colorado River with the Gulf of California. The focus of this study is the basal carbonate member of the southern Bouse Formation along the range front of the southeastern Palo Verde Mountains, CA, and constrains the depositional environment of the region prior to the arrival of the Colorado River. There is no consensus among researchers regarding the depositional paleoenvironment of the basal carbonate member of the southern Bouse Formation. The basal carbonate member has been interpreted to record deposition in either (1) a large inland lake isolated from the ocean, or (2) a transgressive intertidal to subtidal marine seaway. Lack of consensus regarding the origins of the basal carbonate member currently hinders constraints on the tectonics and paleogeography of the region, and understanding the processes by which the Colorado River integrated with the Miocene Gulf of California. A marine origin for the basal carbonate requires at least 330 m of regional uplift since the late Miocene. Conversely, a lacustrine origin requires no uplift, and does not provide any useful constraints. In this thesis I present detailed sedimentologic, stratigraphic, and quantitative data from the basal carbonate member of the southern Bouse Formation, interpret them to provide constraints on depositional paleoenvironments, hydraulic conditions, 1 paleogeographic reconstructions. Additionally, I discuss the implication of these analyses. In Chapter II, I present detailed analyses of lithofacies, bedform architecture, paleocurrents, and paleogeographic reconstructions. I use this data to reconstruct the depositional environments of the basal carbonate member and propose a detailed depositional model that includes hydrodynamics of tidal processes based on empirical studies and published studies of similar tidal deposits. This thesis emphasizes analytical process sedimentology integrated with stratigraphy through interpretation of bedforms and detailed descriptions of lithofacies. Data for this thesis was collected during two winter terms (January-March) in 2018 and 2019. Measured sections, geologic mapping, and paleocurrent data were collected along the rangefront of the southeastern Palo Verde Mountains, CA. Outcrops of the basal carbonate member in the Palo Verde Mountains are the focus of this study because outcrops record the transition from pre-Bouse deposition conditions and highlight the effect of pre-depositional, erosional paleotopography on the facies distribution of the basal carbonate member. Chapter II is presented in manuscript form for the journal Sedimentary Geology and is co-authored with Dr. Rebecca Dorsey. 2 CHAPTER II STRATIGRAPHY, SEDIMENTOLOGY, AND TIDAL PROCESSES OF THE LATE MIOCENE TO EARLY PLIOCENE SOUTHERN BOUSE FORMATION, SOUTHEAST PALO VERDE MOUNTAINS, CALIFORNIA The data in this chapter was developed by both my advisor Dr. Rebecca J. Dorsey and myself. Dr. Dorsey contributed substantially to this work by participating in the development of a depositional model, reviewing manuscripts, and planning data collection I was the primary contributor to the data collection and analysis, constructed a majority of the figures, and did all the writing. 1. Introduction The late Miocene to early Pliocene Bouse Formation, exposed discontinuously along the margins of the lower Colorado River valley (Figure 1), records conditions that existed prior to and during integration of the Colorado River to the Gulf of California. The Bouse Formation is divided into three distinct members – basal carbonate, siliciclastic, and upper bioclastic members – that reflect major changes in depositional processes, sediment sources, and paleoenvironments during initiation and early evolution of the river (e.g., Dorsey et al., 2018). Interpretation of these processes affects our understanding of the regional tectonic evolution and origins of the Colorado River, but contrasting hypotheses hinder progress toward a general consensus on paleogeographic and tectonic reconstructions for this enigmatic formation. Most workers agree that the northern Bouse Formation, north of Parker, Ariz. (Fig. 1), was deposited in a series of interconnected lakes that filled with water and sediment of the first-arriving Colorado River (Spencer and Patchett, 1997; Spencer and Pearthree, 2001; House et al., 2008; Spencer et al., 2013; Pearthree and House, 2014; 3 Bright et al., 2016). However, ongoing debate centers on the depositional paleoenvironments of the southern Bouse Formation in the Blythe Basin (Fig. 1). Two hypotheses have been proposed for the basal carbonate member of the southern Bouse Formation: (1) carbonate deposits accumulated in a saline lake with no connection to the ocean, similar to northern Bouse lakes (Spencer and Patchett, 1997; Roskowski et al., 2010; Spencer et al., 2013; Pearthree and House, 2014; Bright et al., 2016, 2018a, 2018b); or (2) southern Bouse carbonates formed in a tidally-influenced Figure 1: Map of SE California along marine seaway at the north end of the the lower Colorado River Corridor. Outcrops of Bouse Fm. Are in yellow. Miocene Gulf of California oblique rift basin Black box indicates area of Figures 2 and 17. P = Parker, AZ; C = Cibola, (Metzger, 1968; Buising, 1990; McDougall, AZ, B = Blythe, CA. 2008; McDougall and Martínez, 2014; Miller et al., 2014; O’Connell et al., 2017; Dorsey et al., 2018). Previous studies identified tide- generated sedimentary structures and sequences in the southern Bouse basal carbonate member (Buising, 1990; Turak, 2000; O’Connell et al., 2017; Dorsey et al., 2018), but additional data and observations are needed to further test the tidal seaway hypothesis. This paper presents the results of a detailed sedimentologic study of the basal carbonate member of the southern Bouse Formation in the Palo Verde Mountains (Fig. 4 2). We use process-based analysis of sedimentary lithofacies, facies associations, paleocurrent data, and architecture of large-scale bedforms to develop an integrated depositional model for these deposits. The results support a tidal interpretation for mixed carbonate-siliciclastic facies of the basal carbonate member and allow us to clarify the hydrodynamics of this macro- or mega-tidal system. Our paleogeographic reconstruction of the southern Bouse tidal seaway provides new support for post-Miocene uplift in the lower Colorado River region and highlights the value of integrative sedimentology and stratigraphic analysis for understanding the consequences of long-wavelength vertical crustal motions adjacent to an active transform plate boundary. 2. Geologic Background 2.1 Summary of Models for the Bouse Formation The southern Bouse Formation in the Blythe Basin (Fig. 2) has been studied over the past ca. 50 years with the aim of understanding the geologic and hydrologic evolution of the lower Colorado River region, starting with early studies of Metzger (1968) and Smith (1970). The lake hypothesis postulates that the southern Bouse Formation accumulated in a large inland lake that filled with water derived from downstream- directed lake spillover events recorded in the northern Bouse Formation (Spencer and Patchett, 1997; Spencer et al., 2013; House et al., 2008; Pearthree and House, 2014; Bright et al., 2016, 2018a, 2018b). Based on the observation that the 87Sr/86Sr ratio of southern Bouse carbonates is closer to that of Colorado River water than Miocene seawater, Spencer and Patchett (1997) concluded that Bouse carbonates accumulated in a lake filled with Colorado River water. Subsequent studies of carbonate chemistry, 5 isotopes, water budgets, and stratigraphic evidence have lent additional support to the inland saline lake model for the southern Bouse Formation (Poulson and John, 2003; Roskowski et al., 2010; Spencer et al., 2013; Pearthree and House, 2014; Bright et al., 2016, 2018a, 2018b). Figure 2: Geologic map of the southern Blythe Basin (Compiled from Sherrod and Tosdal, 1991; Richard, 1993; Ricketts et al., 2011; Gootee et al., 2016; this study). 6 The marine hypothesis for the southern Bouse Formation postulates that the basal carbonate member accumulated in a marine seaway at the north end of the Miocene Gulf of California oblique-rift basin. In this interpretation the basal carbonate member is interpreted to pre-date arrival of the earliest through-flowing Colorado River and its sediment load (e.g., McDougall, 2008; McDougall & Miranda-Martínez 2014; Dorsey et al., 2018). Previous studies have identified a variety of marine and brackish-water fossils in the southern Bouse Formation, as far north as Parker, AZ, including bivalves, gastropods, barnacles, calcareous algae, ostracodes, and foraminifers (Metzger, 1968; Smith, 1970; Buising, 1990; McDougall, 2008; McDougall and Miranda-Martínez, 2014). Based on physical sedimentology and Fourier transform analysis of rhythmically bedded bioclastic deposits, O’Connell et al. (2017) concluded that the basal carbonate member was deposited by tidal currents in a tide-dominated marginal marine environment. Tide- and wave-generated bedforms have also been documented in Milpitas Wash, AZ, and the Palo Verde Mountains (Buising, 1990; Turak, 2000; Homan, 2014; Dorsey et al., 2018), but recent papers have questioned the tidal origin of these features (e.g., Bright at al., 2018a, 2018b), indicating the need for a more detailed analysis of proposed tidal features. Some studies of stable isotopes (O and C) in Bouse carbonates reveal light isotopic signatures interpreted to support a lacustrine depositional model for the basal carbonate member (e.g., Roskowski et al., 2010; Bright et al., 2016, 2018a, 2018b). Some datasets reveal a southward increase in δ13C toward seawater values (0 per mil) over a distance of ~200 km along the lower Colorado River valley (Poulson and John, 2003), and O and C isotopes show linear covariation toward seawater (Roskowski et al., 2010; 7 Crossey et al., 2015) in a trend that is commonly produced by mixing of river and ocean waters in marine estuaries (e.g., Ingram et al., 1996). Crossey et al. (2015) showed that Sr-isotope ratios in southern Bouse carbonates could be produced by mixing of Colorado River water, radiogenic spring water, and seawater with a plausible range of mixing fractions of ~5 to 50% seawater. Thus, the isotopic data presented to distinguish between lake and marine interpretations appear inconclusive. 2.2 Stratigraphic Framework In this paper we divide the southern Bouse Formation in the Palo Verde Mountains into the basal carbonate member, siliciclastic member, and upper bioclastic member (Fig. 3; Dorsey et al., 2018). The Bouse basal carbonate member overlies Miocene alluvial fan conglomerate and older volcanic rocks in the Palo Verde Mountains (Fig. 3). We divide the basal carbonate member into three units that occur in consistent stratigraphic order: (1) basal travertine that commonly is encrusted directly on Miocene volcanic rock, and rarely is seen in small amounts on Miocene conglomerate; (2) bioclastic unit (focus of this study) comprising a wide range of grain sizes and sedimentary lithofacies Figure 3: Generalized Stratigraphy of the southern Bouse Formation in the documented below; and (3) very fine- southeastern Palo Verde Mountains. grained upper marl. 8 The siliciclastic member overlies the basal carbonate along a conformable but abrupt contact that records the first arrival of Colorado River sediment (Homan, 2014; Dorsey et al., 2018). It ranges up to 200 m thick in subsurface sections (Metzger et al., 1973) and thins to zero thickness where it is cut out along a regional unconformity at the base of the upper bioclastic member. The siliciclastic member is sub-divided into three units: (1) pale to dark green, massive to thinly laminated claystone; (2) red mudstone interbedded with small-scale cross-bedded siltstone and sandstone; and (3) fine to medium-grained channelized, trough cross-bedded Colorado River channel sandstone. Systematic coarsening up-section from green clays to channelized trough cross-bedded fluvial sandstones is interpreted to record progradation of the Colorado river delta (Buising, 1990; Pearthree and House, 2014) and integration of the Colorado river to the northern Gulf of California (Dorsey et al., 2018). The upper bioclastic member unconformably overlies the two older members of the southern Bouse Formation (Fig. 3), and varies in composition from nearly pure carbonate to mixed carbonate-siliciclastic facies to dominantly siliciclastic sand and gravel (Homan, 2014; Dorsey et al., 2018; O’Connell, 2016). Wave-formed ripple bedforms and presence of marine fossil mollusks and calcareous coralline red algae indicate that the upper bioclastic member records deposition in high-energy shallow marine waters in the lower Colorado River valley, after earliest initiation of the Colorado river (Dorsey et al., 2018, 2019). The upper bioclastic member plays a central role in testing hypotheses for processes involved in the initiation and early evolution of the Colorado River (Beard et al., 2016; Dorsey et al., 2018, 2019). 9 This study is focused on exposures of the Bouse basal carbonate member exposed in the southeastern Palo Verde Mountains (Fig. 4). The mountains are composed of Miocene and older volcanic rocks including mafic to dacitic flows and rhyolitic tuffs that dip steeply to the east (Sherrod and Tosdal, 1991). Large normal and oblique faults are common in the Palo Verde Mountains (Fig. 4) and mostly pre-date deposition of the Bouse Formation. Widespread travertine deposits of the basal carbonate member are encrusted directly on volcanic bedrock, thus preserving the latest Miocene to early Pliocene erosional paleotopography of the Palo Verde Mountains. Proximity of the basal carbonate member to the steep range front, and preservation of pre-Bouse erosional paleotopography, make the southeast Palo Verde Mountains an excellent natural laboratory for studying the topographic controls on depositional processes. 3. Overview of Lacustrine and Tidal Sedimentation Shallow, low energy lacustrine settings are dominated by deposition of mud and sand. In these environments, reversing wind directions produce bi-directional currents and temporarily expose parts of the shoreline (Ainsworth et al., 2012). Bi-directional wind currents can produce small scale crossbedding in two dominant directions, and fluctuations in energy levels throughout the lake can produce mud drapes, mud cracks and wavy-lenticular bedding. In higher energy lakes, lateral migration of gravelly longshore bars and sandy stream mouth bars can also produce bi-directional paleocurrents (Fraser and Hester, 1977). Multi-meter scale lake-shore structures, such as gravelly beach ridges formed during the late Pleistocene Lake Lahontan highstand in Nevada, may display opposing cross-bedding directions on lakeward and landward faces 10 Figure 4: Geologic map of the southeastern Palo Verde Mountains showing the major units in the region. All members of the Bouse Formation have been included in a single unit (Tbo). Terrace Gravels (Qg) include all ages of Qi from Gootee et al. (2016). Qal is not colored on the map. 11 (e.g., Blair, 1999). Lakeward dipping strata are deposited by wave processes such as swash on the lakeward face (Schuster and Nutz, 2017), whereas landward dipping tabular cross-beds form as washover deposits during storms on the landward faces of beach ridges (Shaw et al., 2015). Bioclastic carbonate grainstones also form in lacustrine environments characterized by dominance of continental faunal assemblages (Gierlowski-Kordesch, 2010). Bioclastic carbonates can form wavy-lenticular bedding and crossbedding in shallow lake environments (e.g., Ainsworth et al., 2012). In marginal-marine settings, cyclical fluctuations in water depth during daily tides induce horizontal flood (onshore-directed) and ebb (offshore-directed) currents that result in daily filling and draining of coastlines and ocean-connected basins (e.g., Davis, 2012). In tidal environments these currents are the dominant mechanism of sediment transport and can build multi-meter scale compound bedforms. The net transport of sediment in the flood or ebb direction determines whether a tidal system is classified as flood- or ebb- dominant, whereas the duration and velocity of each current determines the asymmetry of a tidal system (Dronkers, 1986; Brown and Davies, 2010). Bathymetry and geometry of tidal basins exert the primary control on tidal range, current duration, and current velocity in tidal environments (Brown and Davies, 2010). Deposits most commonly associated with tidal depositional systems include wavy-flaser-lenticular bedding (Reineck and Wunderlich, 1968) and herringbone crossbedding formed by bimodal, bipolar currents with interceding periods of slackwater (e.g., Davis, 2012; Daidu et al., 2013). While mud-rich deposits often are not diagnostic of deposition by tidal currents (Stride, 1982; Davis, 2012), the internal structures and geometries of cross-bedded sands and gravels have been shown to be uniquely diagnostic of tidal depositional processes and 12 environments (Stride, 1982; Brown and Davies, 2010; C. Olariu et al., 2012; Davis, 2012; Longhitano et al., 2012; Longhitano, 2013; Longhitano and Steel, 2017), especially when coupled with mud-rich facies that commonly are found in tidal facies associations. Large sand sheets and isolated sand banks are well described from modern and ancient tidal environments (Dalrymple, 1984; Berné, 2000; Santoro et al., 2002; Olariu et al., 2012; Reynaud and Dalrymple, 2012; Longhitano, 2013; Longhitano and Steel, 2017), and are characteristic features of high energy tidal currents in shoreface and offshore environments. Large sand sheets are produced by the growth and migration of compound bedforms that are built from smaller bedforms (Dalrymple, 1984; C. Olariu et al., 2012; M. I. Olariu et al., 2012). Large compound bedforms in tidal environments typically are constructed by deposition from smaller-scale individual bars or dunes (Fig. 5). Tidal bars and dunes are distinctly different types of bedform that represent unique stratal geometries, mechanisms of formation, and depositional conditions. Compound dunes (Fig. 5a) are large bedforms (1-15 m) with crests oriented transverse to flow direction, in which bedform migration occurs primarily by forward accretion (Dalrymple, 1984; Berné, 2000; C. Olariu et al., 2012). Superimposed, smaller-scale simple dunes have foresets oriented similar to down-current-dipping lee faces that make up the master surfaces of compound dunes. Compound dunes can form within tidal channels or as isolated sand sheets and bars. Importantly the height of compound dunes is typically no more than ~20% of water depth (C. Olariu et al., 2012), providing a minimum constraint on paleo-water depth. In contrast, tidal bars are elongate bedforms with crests oriented parallel to the dominant current direction (Fig. 5; Dalrymple, 1984; Dalrymple et al., 1990; Fenies and Tastet, 1998; C. Olariu et al., 2012; M. I. Olariu et al., 13 2012). Tidal bars migrate by lateral accretion, perpendicular to current direction, and often are found at the margins of tidal channels, and tidal bar heights are commonly up to 100% of water depth (Dalrymple et al., 1990; Dalrymple and Choi, 2007; M. I. Olariu et al., 2012; Reynaud and Dalrymple, 2012; C. Olariu et al., 2012). The different behavior and scales of bars versus dunes provide useful criteria for constraining paleoenvironmental reconstructions and interpretation of paleocurrent data from the stratigraphic record. Figure 5: Schematic diagram of A) tidal dunes and B) tidal bars showing the relationship between bedform geometry, flow depth, current direction, and accretion direction. Flow depths in A and B are equal. h = bedform thickness. In this paper we use the terminology of Ashley (1990) and C. Olariu et al. (2012) to document the major architectural features of tidal dune and bar cross bedding in the southern Bouse Formation. This system is the only published classification that is suitable for describing and interpreting the wide array of cross-bedding scales and 14 geometries observed in this study. The smallest architectural components of compound dunes are 2D and 3D simple dunes with foresets (1st-order surfaces) whose down-dip direction is parallel to the current direction (Fig. 6). Master surfaces (2nd-order surfaces) mark the boundaries between stacked simple dunes and represent the lee faces of migrating compound dunes (Dalrymple, 1984; Berné, 2000; C. Olariu et al., 2012). Figure 6: Fundamental architectural components of a tidal compound dune and their relation to bedform migration and current direction. Vertical exaggeration is ~5x to illustrate geometric relations. C.D. = Compound Dune Compound dunes are built by successive stacking of simple dunes, and the direction of compound dune migration is recorded in dip direction of the master surfaces. Migration of compound dunes through forward accretion is facilitated by the migration of simple dunes over the crest and down the lee faces of compound dunes (Allen, 1980). Compound dune complexes (Fig. 6) are built by the stacking of compound dunes bounded by 3rd order surfaces, and can extend for kilometers as a result of compound dune migration over regional 4th order surfaces (C. Olariu et al., 2012). Simple dunes and compound dunes may be 2D or 3D, and may have sigmoidal or planar-tabular 15 geometries, which are indicative of differing flow conditions. Recognition of these architectural elements and their relationships in outcrop is necessary to differentiate dunes from bars and allows us to identify tidal process in near-shore and off-shore environments. 4. Methods Data collected for this study include representative measured sections, field photos that display important features of sedimentary lithofacies, bedform geometries and stratal architecture, measurements of bedset and compound dune thicknesses, and paleocurrent measurements (primarily dip direction on well-defined foreset surfaces). Stratigraphic sections (see Appendices A&B) were measured bed-by-bed and include bed thickness and geometry, grain size, sorting, composition, sedimentary structures, and fossils. Bed set thicknesses of sigmoidal and planar-tabular simple dunes were measured within and outside of compound dunes at their thickest point. Compound dune thicknesses were measured at the thickest point with a meter stick where possible and (where cliff exposures were not accessible) using a Nikon laser rangefinder. Measurements of paleocurrent indicators, master surfaces, and bedding include strike, dip, and dip angle, and are corrected for gentle structural dips using Stereonet 9 software (see appendices C-E). We constructed and interpreted facies associations by comparison to similar published case studies. Interpretations of depositional environments from this and previous studies (Metzger, 1968; Homan, 2014; O’Connell, 2016; Dorsey et al., 2018) were used as constraints for our paleogeographic reconstruction (Fig. 16). Reconstruction 16 of the paleo-shoreline was completed using minimum water depth estimates from compound dune thicknesses from the Stallard Area, Petroglyph Park, BP4, and BP5 (Fig. 2). Using a locality-by-locality approach, we calculated the intersection of present topography and a plane representing the height of water over each locality in QGIS. Measured gentle tectonic dips were used to restore cross bedding and other features to their original, pre-tilting orientation. 5. Sedimentary Lithofacies Analysis We divide the bioclastic unit of the Bouse basal carbonate member into 15 distinct lithofacies based on grain size, composition, sedimentary structures, and sorting (Table 1). These lithofacies are grouped into two categories based on dominant composition: siliciclastic-dominant versus carbonate-dominant. Interbedding of different facies and sediment types permits designation of two main facies associations: (1) Tidal Fan Delta Facies Association, and (2) Tidal Dune Field Facies Association (Table 2). 5.1 Siliciclastic-Dominant Facies Four types of siliciclastic-dominant facies in the study area include: horizontally stratified pebbly sandstone; horizontally stratified conglomerate; unstratified conglomerate; and cross-bedded conglomerate. Carbonate percentage in conglomerate matrix ranges from 0 to 80% in these facies. Siliciclastic-dominant facies alternate vertically and laterally with carbonate-dominant facies along the margins of the basin. Horizontally stratified pebbly sandstone (Facies S1, Table 1) consists of medium- to coarse-grained, moderately sorted sandstone containing 20-30% subrounded, sub- equant pebbles (Fig. 7a). No preferred orientation was observed in the pebbles. Sand and 17 pebbles are derived from local volcanic bedrock. Facies S1 contains 0% carbonate grains. Stratified conglomerate (Facies S2, Table 1) is matrix-supported, moderately to poorly sorted, granule to pebble conglomerate with minor cobble lenses (Fig. 7b). This facies displays horizontal to low-angle cross stratification. Granule and pebble-sized lasts are subangular to subrounded, and cobbles are angular to subangular. Facies S2 matrix ranges from 0-20% carbonate. Unstratified conglomerate (Facies S3, Table 1) consists of clast-supported, poorly sorted, unstratified, subangular pebble to boulder conglomerate (Fig. 7C). This unit can be either ungraded or inversely graded. Clasts are locally-derived volcanic rocks. Boulder-sized clasts may be up to 2 meters across. This lithofacies is laterally discontinuous and thins to zero thickness over horizontal distances of <200 m (often <50 m). Facies S3 displays the greatest variation in matrix composition, with matrix composition ranging from 0-80% carbonate. Where facies S3 directly overlies carbonate- dominant facies, the matrix composition contains higher percentages of carbonate (Fig. 7e). Cross-bedded conglomerate (Facies S4, Table 1) consists of matrix-supported, moderately to well sorted, granule to pebble conglomerate with subrounded volcanic clasts (Fig. 7D). Facies S4 has planar-tabular cross-bedding with bedsets ranging from 0.2-0.8 m thick. Cross-bedding may be uni-directional or bi-directional and is often channelized. Matrix composition ranges from 10-80% bioclastic carbonate. Facies S4 is systematically observed stratigraphically above the first occurrence of bioclastic carbonate. 18 Figure 7: Field photos of siliciclastic-dominant facies with interbedded carbonate- dominant facies. A) Horizontally stratified, pebbly sandstone. B) Horizontally stratified to low angle cross-bedded sandy pebble conglomerate overlain by horizontally stratified calcisiltite and sandy grainstone. C) Unstratified, inversely graded, pebble to boulder conglomerate, with carbonate-dominant facies above and below. D) Well sorted, subrounded, cross-bedded, granule to pebble conglomerate. E) Unstratified, ungraded, pebble to cobble conglomerate interbedded with pebbly, sandy grainstone. 19 Table 1: Lithofacies Lithofacies Facies Description Interpretation # Siliciclastic S1 Horizontally bedded Medium- to coarse-grained Upper plane bed Dominant pebbly sandstone. deposition in distal alluvial fan. S2 Moderately- to poorly-sorted, horizontally to low- Deposition by sheet angle cross-stratified, granule-pebble floods on medial conglomerate with minor cobble lenses. alluvial fan. Carbonate composition of matrix varies from 0- 20% S3 Poorly sorted, unstratified, ungraded to inversely Deposition by debris graded, pebble to boulder conglomerate. Matrix flow in proximal to composition varies from 100% siliciclastic to 70- medial alluvial fan. 80% bioclastic carbonate. S4 Moderately- to well-sorted, sub-rounded, granule Deposition by to pebble conglomerate with tabular cross- migration of gravelly bedding. Cross-bed sets range from 0.2 - 0.8m point bars in braided thick and have channel geometries. channels of a fan delta. SC1 Poorly sorted, unstratified, clast-supported, Deposition by pebble to cobble conglomerate with fine-grained sediment gravity flow. carbonate grainstone matrix. Clasts display travertine encrustation. Carbonate C1 Massive to rhythmically bedded calcisiltite with Deposition by Dominant interbedded siliciclastic and lime mud. suspension settling in upper intertidal flats C2a Wavy-flaser-lenticular bedded and horizontally Deposition by low laminated, interbedded, very fine- to fine-grained energy wave sandy grainstone and calcisiltite. oscillation and suspension settling on intertidal flats. C2b Wave ripple laminated, very fine to fine-grained Deposition by low sandy grainstone with thin lime mud interbeds. energy wave Lime mud interbeds display desiccation cracks oscillation and suspension settling on intertidal flats. C2c Massive/bioturbated very fine- to med-grained Deposition by sub- sandy grainstone with or without calcisiltite critical flow in bottom component. Rhodoliths, micro mollusks and sets of small-scale gastropods common. Bioturbated variety displays intertidal compound contains Thalassinoides burrows locally. dunes 20 Table 1 (continued) Lithofacies Facies Description Interpretation # C3a Massive to weakly stratified, medium-grained to Rapid deposition in granule-sized sandy grainstone with abundant bottomsets of subtidal rhodoliths, mollusks, and barnacles. compound dunes. C3b Horizontally stratified, fine- to coarse-grained Deposition by critical sandy grainstone. Locally contains angular to sub- to flow in bottomsets rounded pebbles. of large-scale subtidal compound dunes. C3c Weakly stratified, poorly sorted, fine- to coarse- Rapid deposition by grained pebbly, sandy grainstone. high energy currents. C3d Weakly stratified, coarse-grained to granule- High energy re- sized, sandy grainstone with thin, granule-pebble working of granule- conglomerate lenses. pebbles in intertidal flats. C4 Well sorted, fine-grained to granule-sized sandy Deposition by grainstone with small- to intermediate-scale migrating 2D tidal tabular cross-bedding. Cross-bed sets range from dunes in lower 0.05-0.5m thick. Crossbed sets display bi- intertidal flats. directional transport. C5 Well sorted, medium-grained to granule sized Deposition by sandy grainstone with large-scale sigmoidal migrating 2D to 3D cross-bedding. Cross-bed sets range from 0.4-2.5 tidal bedforms in a m thick. Granule sized shell fragments on foresets shallow to middle are common. subtidal environment. 5.2 Carbonate-Dominant Facies We divide carbonate-dominant facies into 5 lithofacies with internal variations (Table 1, Figure 8). When describing carbonate-dominant facies, we used the terms “sandy” and “pebbly” in reference to the siliciclastic component which ranges from 5- 40%. Carbonate-dominant facies are commonly interbedded and are differentiated on the basis of grain size, scale, and style of sedimentary structures. Carbonates were produced in-situ by organisms or through inorganic precipitation. 21 Figure 8: Field photos of carbonate dominant facies. A) Wavy-Flaser-Lenticular bedded grainstone and calcisiltite. B) Massive to weakly stratified grainstone. C) Horizontally stratified, fine- to medium-grained pebbly, sandy grainstone. D) Horizontally stratified, very fine- to fine-grained sandy grainstone with lime mud interbeds. E) Large-scale (0.5- 2 m thick), medium-grained to granule-sized, sigmoidal, cross-bedded grainstone. F) Small scale (10-20 cm thick) medium-grained to granule-sized, planar cross-bedded sandy grainstone. Color divsions on staff are 10 cm; Hammer = 32.5 cm; Sharpie = 13.6 cm . 22 Encrusted-clast conglomerate (Facies SC1, Table 1) consists of poorly sorted, unstratified, subrounded pebble to cobble conglomerate with fine-grained sandy grainstone matrix. Locally-derived clasts are fully encrusted by travertine and surrounded by a sandy carbonate matrix. Facies SC1 is not observed in contact with volcanic bedrock and is instead found as a discontinuous, 6-10 cm thick unit overlying Miocene conglomerate and Bouse conglomerate. Interbedded calcisiltite (Facies C1, Table 1) is well-sorted, massive to rhythmically bedded silt-sized carbonate unit interbedded with siliciclastic and carbonate mud. Facies C1 displays reed casts and burrows along bedding plane exposures. Massive beds are up to 10 cm thick, and rhythmite beds are <1 cm thick. Stratigraphically, Facies C1 is the oldest facies of the bioclastic unit. This unit is equivalent to the fine-grained heterolithic facies used in fourier transform analysis by O’Connell et al. (2016). Facies C2a, C2b and C2c (Table 1) contain ripple-scale cross-laminations, horizontal laminations, and massive bedding. Facies C2a and C2b are very fine- to fine- grained sandy grainstone with interbeds of calcisiltite and lime mud. Facies C2c consists of fine- to medium-grained sandy grainstone that locally contains calcisiltite. C2a displays abundant wavy-flaser-lenticular bedding (Figure 8a) along with minor horizontal laminations. C2b displays horizontal and wave ripple laminations and bedding plane exposures of lime mud in Facies C2b show grainstone-filled desiccation cracks (Fig. 8d). Facies C2c contains micromolluscs, rhodoliths and gastropods, commonly associated with Thalassinoides burrows. Individual grainstone beds in Facies C2a and C2b range from 2 to 6 cm thick, and finer interbeds are typically <1 cm thick. Bed thicknesses in Facies C2c range from 3 to 10 cm. 23 Facies C3a-d (Table 1) consist of fine-grained to granule-sized, moderately to poorly sorted sandy grainstone with locally-derived volcanic pebbles. Facies C3a, C3c, and C3d are weakly stratified and have an average bed thickness of 5 cm. Facies C3b (Figure 8c) is well stratified and has an average bed thickness of 3 cm. Facies C3a (Fig. 8b) has no pebble sized clasts and contains abundant molluscs, gastropods, and barnacles. Locally, Facies C3a contains Thallasinoides burrows. Facies C3b contains angular, locally-derived pebbles within well stratified beds. C3c lacks internal stratification observed in C3b, and contains locally-derived pebbles. Facies C3d contains abundant poorly sorted, siliciclastic granule and pebble lenses. Facies C4 and C5 (Table 1) comprise fine-grained to granule-sized, well sorted, cross-bedded sandy grainstone. Cross-beds in Facies C4 (Fig. 8d) have planar-tabular geometries and bed set thicknesses ranging from 0.05-0.5 m thick. Paleocurrents in Facies C4 are bidirectional and rectilinear. Facies C5 (Fig. 8e) has sigmoidal cross-beds with thicknesses from 0.4-2.5 meters. Paleocurrents in Facies C5 are unidirectional. Shell fragments are concentrated on reactivation surfaces and foresets within simple dunes. Facies C4 and C5 are observed individually, and are also commonly observed within larger, multi-meter thick compound bedforms. 5.3 Facies Associations In this study we recognize distinctive vertical and lateral stacking and interbedding of lithofacies that comprise three main facies associations (Table 2): (1) Distal Alluvial Fan; (2) Tidally-Influenced Fan Margin, and (3) Tidal Dune Field facies. 5.3.1 Alluvial Fan Facies Association (FA1) 24 Miocene conglomerate of FA1 directly overlies Miocene and older bedrock and underlies the Bouse Formation. This unit includes Facies S1-S3 (pebbly sandstone and conglomerate), but without any carbonate in clast or matrix compositions. Facies S2 (stratified conglomerate) and S3 (unstratified conglomerate) are common constituents of FA1 (Fig. 9). Facies S1 is less common and occurs as discontinuous beds of stratified pebbly sandstone within conglomerate facies. This facies association can be 10s of meters thick, although a maximum thickness cannot be determined because the contact with underlying bedrock dips into the subsurface. Table 2: Facies Associations Facies Association Lithofacies Interpretation Alluvial Fan (FA1) S1, S2, S3 Deposition by sheet floods and debris flows in a proximal to distal alluvial fan setting. Tidally-influenced Fan S1, S2, S3, S4, SC1, C1, Transgression of tidal flats Margin (FA2) C2a, C2b, C2c, C4 onto alluvial fans. Sheet floods and debris flows build out shoreline in active alluvial channels. Inactive alluvial channels are dominated by tidal processes. Tidal Dune Field Facies C2b, C3a, C3b, C3c, C3d, Deposition by large scale Association (FA3) C4, C5 (5m thick) 2D and 3D tidal compound dunes migrating along axis of an ebb- dominated tidal seaway. 25 Figure 9: Field photos of the Alluvial Fan Facies Association (FA1) A) Interbedded, stratified conglomerate (Facies S2) and unstratified conglomerate (Facies S3). B) Horizontall to low-angle cross-stratified conglomerate. C) Poorly sorted, weakly stratified to unstratified conglomerate. Hammer is 32.5 cm; Staff is 1m and has 10 cm divisions. We interpret the Alluvial Fan Facies Association to record deposition in subaerial alluvial fans. Where facies S2 and facies S1 are most abundant, sheetfloods were the primary mode of deposition. In localities where facies S3 (unstratified conglomerates) is abundant, deposition by debris flows was the dominant mechanism for building alluvial fans. These two processes are not mutually exclusive, and evidence for both processes in a single alluvial fan is common. Large boulders (> 2m across) are observed within extensive sheet flood deposits. This suggests initial transport via debris flow and subsequent winnowing and reworking of fines through sheet floods, leaving behind large boulder lags. The presence of both sheetflood and debris flow deposits could reflect lateral changes in depositional environments from proximal to distal alluvial fan, or intermittent debris flows extending out into distal alluvial fan environments. 26 5.3.2 Tidally-Influenced Fan Margin Facies Association (FA2) This facies association is characterized by complex interbedding of siliciclastic- dominant and carbonate-dominant lithofacies near the margins of the basin (Table 2, Figs. 10, 11). FA2 is transitional between late Miocene alluvial fan conglomerate (FA1) and subtidal carbonate-dominant facies (FA3), and is absent in areas where subtidal deposits of FA3 rest directly on travertine-encrusted Miocene volcanic rock. Measured sections display variations in the ratio of siliciclastic-dominant to carbonate-dominant facies (S:C ratio) and relative abundance of Facies S2 and S3 (stratified and unstratified conglomerate). These differences define two variants: FA2a with a higher ratio of siliciclastic deposits and mainly stratified conglomerate in the siliciclastic component; and FA2b with a higher ratio of carbonate deposits and dominantly unstratified conglomerate in the siliciclastic component. In sections with a high S:C ratio, the base of FA2a is marked by the lowest carbonate-rich deposits above Miocene conglomerate (Fig. 11a). Typically, the lowest carbonate is a <30 cm thick bed of fine-grained calcisiltite or grainstone (C1 or C2). Facies S2, stratified conglomerate, is the dominant lithofacies occurring in thick (0.25-2 m) continuous beds, with thinner (0.15-0.3 m) interbeds and discontinuous lenses of S3 (unstratified conglomerate). We observe an up-section decrease in the S:C ratio and a subtle increase in grain size of carbonate-dominant facies (Fig. 11). Stratigraphically higher unstratified conglomerate forms laterally discontinuous beds averaging 0.2 m thick. Sections with a low S:C ratio (FA2b, Fig. 11b, 11c) are characterized by abundant carbonate-dominant facies and unstratified conglomerate (S3) beds in the siliciclastic 27 Figure 10: Field photos of the bioclastic unit facies associations. A) Sigmoidal simple dunes in the tidal dune field facies association (FA3). B) Sigmoidal compound dunes in the tidal dune field facies association (FA3). C/D) Interbedded tidal flat, debris flow, and sheetflood deposits of the tidally influenced fan margin facies association (FA2). Staff is divided into 10 cm tall stripes. Person in D is approximately 190 cm. 28 Figure 11: Representative measured sections of the tidally influenced fan margin facies association. A-C) Sections PVM-6, PVM-9 and KG-6 showing lithology, lithofacies, and interpretations. D) Key to symbology used in Figures 11 and 12. 29 component. In these sections, Facies S2 and S3 occur in laterally discontinuous beds 0.2- 1 m thick, or as thin lenses (0.1-0.15 m) in Facies C3d. We interpret facies association FA2 to record the transition from pre-inundation Miocene alluvial fans (FA1) to high-energy subtidal conditions that produced the cross- bedded bioclastic deposits of FA3. Pre-Bouse Miocene conglomerate (FA1) was deposited in distal alluvial fans by sheet floods (Facies S1, S2) and debris flows (Facies S3). Conglomerate interbeds of FA2a have similar composition and texture as the deposits of underlying alluvial-fan association FA1. Carbonate-dominant facies C1-C3 record deposition by wave action and tidal currents with intermittent suspension settling during slackwater conditions (Table 1). Common interbedding and lateral interfingering of alluvial fan and tidal deposits records migration of active alluvial channels that built out the shoreline, while abandoned portions of alluvial fans became inundated by intertidal flats at the margins of a tidal seaway (see below). Sections with high S:C ratios and abundant Facies S2 (stratified conglomerate) formed on active, sheetflood-dominated distal alluvial fans that underwent rare inundation and tidal deposition during rare marginal-marine floods produced by storm-driven anomalously high hides. Tidal-flat conditions became dominant up-section following abandonment of the alluvial fan, decreased siliciclastic sediment supply, or an increase in average water depth due to rising relative sea level. Sections with low S:C ratios and more unstratified conglomerate formed on fan-fringing tidal flats where sediment supply from debris flows was intermittent. Coarsening-up rends in carbonate-dominant facies record a transition from low-energy upper intertidal flats, to increased energy conditions associated with lower intertidal to shallow subtidal environments. Our observations are consistent with studies 30 of modern tectonically-confined transgressive tidal environments (e.g. Longhitano et al., 2013). 5.4 Tidal Dune Field Facies Association (FA3) This facies association contains coarsening-up successions of cross-bedded sandy grainstones and calcisiltites with little to no siliciclastic-dominant facies (Figs. 9, 11; Table 2). Facies C5 (cross-bedded sandy grainstone) is the dominant sediment type and includes abundant inclined surfaces where paleocurrent measurements were collected. FA3 makes up the majority of bioclastic carbonate deposits in the southeastern Palo Verde Mountains. This facies association is distinguished by abundance of medium- grained to granule sized, multi-meter scale cross-bedded sandy grainstone. Cross-beds are abundant and provide useful paleocurrent and hydrodynamic information (Section 6, below). All localities of FA3 reveal strong coarsening-up in carbonate-dominant deposits, with facies S2-S4 making up ≤ 10% of this facies association. We interpret Facies Association 3 to record migration and deposition of coarse- grained bioclastic sediment in subtidal compound dune fields that formed large carbonate sand sheets in a transgressive tidal seaway. Large-scale compound bedforms with bimodal paleocurrent directions (see below) documented in this study are characteristic of tidal environments (e.g. Dalrymple, 1984; Berné, 2000; C. Olariu et al., 2012; M. I. Olariu et al., 2012) and are not seen in lakes. Coarsening-up trends record increased water depth and current velocities during deposition. Fine-grained carbonate sand, silt, and mud in the lower parts of each section accumulated in low-energy intertidal flats and are overlain by large-scale compound dunes (Fig. 12) that require increased current velocity and water depth during deposition. 31 Figure 12: Representative measured sections of the tidal dune field facies association. Section PP-2 in Petroglyph Park shows a transition from shallow intertidal flats to subtidal compound dunes. Section SR-5 from the Stallard Area shows a transition from Miocene alluvial fan deposits covered by Bouse travertine into shallow intertidal flats and then into subtidal compound dunes. Both sections coarsen upwards, and represent an up section rise in relative seal level RSL. 32 Up-section coarsening in large-scale cross beds also reflects hydraulic sorting during traction transport. Coarse-grained to granule-sized particles are deposited on the lee-faces of compound bedforms, and very-fine to medium sand is transported out in front of the compound bedform and deposited as bottomsets. An upward increase in grain size is typical of compound dunes and results from forward migration of coarse-grained foresets over finer-grained proximal to distal bottomsets (C. Olariu et al., 2012; M. I. Olariu et al., 2012). In contrast, fining-upward is commonly seen in deposits of tidal bars. Only upward-coarsening vertical trends were observed in compound bedforms in this study. The absence of mud-rich and siliciclastic-dominant facies in FA3 indicates deposition away from basin-margin alluvial fans. The characteristics of this facies association are consistent with large sand sheets in modern and ancient transgressive tidal systems (Stride, 1982; C. Olariu et al., 2012; M. I. Olariu et al., 2012; Reynaud and Dalrymple, 2012; Longhitano, 2013; Longhitano and Steel, 2017). 6. Sedimentary Bedform Analysis Analysis of sedimentary bedforms provides insights into hydraulic conditions, current dynamics, and water depth of tidal depositional systems (Stride, 1982; Dalrymple, 1984; Dalrymple et al., 1990; C. Olariu et al., 2012; Longhitano et al., 2012; Longhitano, 2013; Longhitano and Steel, 2017). Two areas in the southeastern Palo Verde Mountains, the Stallard Area and Petroglyph Park (Fig. 2), contain excellent exposures of large-scale cross bedding in carbonate-dominant facies (FA3) that permit detailed analysis of stratal geometries and their origins. In this section we use data from these exposures to document the architecture of compound and simple dune bedforms, measure and classify 33 master surfaces and simple foresets, and analyze paleocurrent data to reconstruct hydraulic conditions and paleogeography. 6.1 Compound Dune Architecture Exposures of cross-bedding at Petroglyph Park and the Stallard Area (Fig. 4) reveal architectural elements ranging from simple dunes to compound dunes to compound-dune complex scale. In one example at Petroglyph Park, two compound dunes are defined by 3rd-order bounding surfaces and each compound dune is composed of numerous smaller-scale simple dunes measuring 0.05-1.8 m thick (Fig. 13a). Internal foresets (1st-order surfaces) within simple dunes dip 18-29°, whereas master surfaces that define the boundaries of simple dunes (2nd-order surfaces) are generally shallower and dip 8-20° (Fig. 13a). Master surfaces are non-uniform and irregular. Larger (0.5-2.5 m) simple dunes at Petroglyph Park have sigmoidal geometries with south-dipping lee faces, while smaller dunes (0.05-0.5 m) are both sigmoidal and tabular. Tabular varieties are laterally discontinuous, often truncated by foresets of larger sigmoidal simple dunes. Compound dunes at Petroglyph Park range from 4.0 to 5.5 m tall. Their geometry is distinctly sigmoidal, with thin tails in the north and thick lee faces in the south. The dune field here rests on a regional 4th order surface above shallow tidal rhythmites (Fig. 13 a). Simple dunes in the Stallard Area (Fig. 4) are similar to those observed at Petroglyph Park. Foresets (1st-order surfaces) dip 18-31° east, and master (2nd-order) surfaces have a range of dips from 3° to 23°. Simple dunes at all scales are dominantly sigmoidal with uncommon tabular cross-beds. One representative exposure (Fig. 14a) reveals a network of nested and laterally stacked compound dunes within a larger-scale compound dune complex spanning 100s of meters in horizontal distance. 34 Figure 13: Petroglyph Park compound dune field. A) Annotated photo showing architectural elements of two compound dunes. B) Rose diagram showing orientations of foresets and master surfaces. Area where conditions are met for compound dunes is bounded by dashed lines. C) Polar plot of simple dune thickness versus paleocurrent orientation. Note that larger bedforms are directed to the south. 35 Figure 14: Stallard Area Compound Dune Field. A) Annotated photograph showing the architectural elements of compound dunes in a compound dune complex, B) Rose diagram comparing orientations of simple dune foresets and master surfaces. Area that fits criteria for compound dunes is bounded by dashed lines. C) Polar plot comparing simple dune thickness. Note that east directed simple dunes are the thickest. 36 `Compound dunes in the Stallard Area range from 3.0 to 5.5 m high and are separated from adjacent compound dunes by third order surfaces dipping 15-25° (Fig. 14a). Individual compound dunes have strongly sigmoidal geometries with east-dipping lee faces that transition laterally to the east into ripple laminated and bioturbated bottomsets over distances of 20-30 m. Planar tabular compound dunes are rare. The architecture of the compound dune complex (Fig. 14a) is consistent with east-directed migration and stacking of compound dunes in a dune field to form a laterally continuous sand sheet. 6.2 Paleocurrents and Bedform Thickness Paleocurrent data collected for this study permit recognition of cross-bedding created by dunes versus bars. At Petroglyph Park, dip directions of simple dune foresets (1st-order surfaces) are oriented within 45° of master surfaces (2nd-order surfaces) (Fig. 13b), consistent with conditions required for compound dunes (Dalrymple, 1984). Simple dunes show bi-directional, rectilinear paleocurrent directions oriented N-S, and a minor number of E-W directions (Fig. 13b). Most master surfaces of compound dunes at Petroglyph Park dip south, and a smaller number dip east. No north- or west-dipping master surfaces were observed. Figure 12c shows that north-directed simple dunes are <0.25 m thick, whereas south-directed simple dunes are typically larger (most are >0.5 m) and range up to 1.85 m thick. East-directed simple dunes are <0.5m thick, and are consistently larger than north- and west-dipping simple dunes (Fig. 13c). Data from the Stallard Area similarly show that simple dune foresets and master surfaces are oriented within 45° of each other (Fig. 14b), confirming their classification as compound dunes. Paleocurrents from simple dunes in this area are bi-directional and 37 rectilinear with E-W orientations and dominantly eastward-directed paleocurrents. Master surfaces in the Stallard Area dip only in the dominant paleocurrent direction (east); west- dipping master surfaces were not observed. A plot of simple dune thickness vs. paleocurrent direction (Fig. 14c) shows a systematic and significant difference between thicknesses of east-dipping versus west-dipping cross-bed sets. This comparison shows that east-directed simple dunes are 0.1-1.5 m thick, whereas west-directed simple dunes are <0.4 m and most are <0.25 m thick (Fig. 14c). One 0.8-m thick simple dune has NNW-directed paleoflow, but other bedforms of similar scale and orientation were not observed. In summary, paleo-dune fields in the study area show a consistent pattern of paleocurrents and simple dune thicknesses that shed light on the hydrodynamics of the system where they formed. Data from the Stallard area and Petroglyph Park localities reveal highly organized bi-modal paleocurrent directions with dominant and subordinate modes, and evidence that compound dunes migrated only in the dominant current direction (Figs. 13, 14). Simple dunes that dip in the dominant current direction are consistently larger than simple dunes that dip in the subordinate direction, and all subordinate simple dues are <0.5 m thick. 6.3 Water Depth Estimates from Compound Dune Thicknesses Compound dunes that form in tidal environments develop in quasi-equilibrium with fluctuating water, and therefore provide information about average water depth (Allen & Friend, 1976; Dalrymple et al., 1978; Dalrymple, 1984; C. Olariu et al., 2012). Empirical and theoretical studies have shown that compound dune heights are ≤20% of average water depth, whereas bars are commonly up to 100% of average water depth (C. 38 Olariu et al., 2012). These bounding values, and presence of abundant cross-bedding formed by migrating dunes in the study area, allow us to estimate minimum average water depth based on measured compound dune thicknesses (Table 3). Minimum water depths were calculated using two methods: (1) compound dune height = 20% of water depth, and (2) inverting the empirical relation H=0.086*h1.19 (H=Dune height; h=water depth; Allen, 1984) and solving for water depth. The average thickness of 18 compound dunes measured in this study is 3.9±0.8 m. Petroglyph Park compound bedforms are on average larger (4.5±0.9 m) than those in the Stallard Area (3.8±0.7m). Estimates of water depth based on all measured compound dunes using the first method above give an average water depth of 20 ± 1 meters, and calculations using the empirical relationship (second method) yield an average water depth of 25 ± 1 m. Average water depth estimated from the empirical relation is consistently 5 m deeper than values calculated using the 20% estimate in both the Stallard Area (20%: 19 ± 1 m; empirical: 24 ± 1 m) and Petroglyph Park (20%: 22 ± 2 m; empirical = 27 ± 2 m). Both estimates indicate that the Stallard Area dune field formed in shallower water than the Petroglyph Park dune field, though this difference could be negligible if compound dune heights in the Stallard Area represent less than 20% of average water depth. In the absence of any evidence to suggest a different relationship between water depth and dune height in the two dune fields, we use the estimated minimum average water depth at both localities using the same equation from Allen (1984), since calculations using this equation closely match empirical observations. Summarizing, we estimate paleowater depths of 24 ± 1 m for the Stallard area and 27 ± 2 m for the Petroglyph Park dune field. 39 Table 3: Compound Dune Thicknesses and Water Depth Estimates Compound Dune Compound Dune Min Water depth (h = Water depth height (m) 20% of Wd) (Allen 1984) SR1 4.4 22 27 SR2 5.2 26 31 SR3 4.5 23 28 SR4 4.1 21 26 SR5 3.2 16 21 SR6 3.8 19 24 SR7 3.4 17 22 SR8 3.4 17 22 SR9 3.2 21 SR10 3.6 18 23 SR11 3.1 16 20 SR12 2.8 14 19 SR13 3.1 16 20 SR14 4.9 25 30 PP1 4.8 24 29 PP2 5.2 26 31 PP3 4.6 23 28 PP4 3.2 16 21 Petroglyph Park 4.5 ± 0.9 22 ± 2 27 ± 2 Average Stallard Area 3.8 ± 0.7 19 ± 1 24 ± 1 Average Total Average 3.9 ± 0.8 20 ± 1 24 ± 1 40 7. Depositional Model and Buzzards Peak Localities Lithofacies analyses, paleocurrent data, and water depth estimates presented above shed light on depositional processes and paleoenvironments of the Bouse basal carbonate member in the Palo Verde Mts. Based on comparison to similar deposits documented in other studies (e.g. Longitano et al., 2013), we developed a depositional model and paleogeographic reconstruction for the basal carbonate member (Figs 15 – 17). The model is further constrained by other studies of the southern Bouse Formation (Homan, 2014; O’Connell et al., 2017; Dorsey et al., 2018) and the physiography of the lower Colorado River valley and southern Blythe Basin (Figs. 1, 2). 7.1. Depositional Model Data and results presented above show that the basal carbonate member accumulated in a transgressive, macro- to mega-tidal, tide-dominated marine seaway (Fig. 15). Tidal seaways are marine connections between adjacent basins that are dominated by strong tidal currents flowing parallel to the long axis of the seaway (Longhitano and Steel, 2017). Tidal straits are similar to tidal seaways but they are narrower than seaways and become tide-dominated only after amplification of tidal currents due to reduction in cross-sectional area of the basin (Pugh, 1987; Longhitano, 2013; Longhitano and Steel, 2017). A diagnostic feature of tidal straits and seaways is the strait-margin zone, where siliciclastic sediment from adjacent highlands is transported toward the basin axis by mass-flow and traction processes (Longhitano, 2013). Tidal straits and seaways are also characterized by large sand sheets and dune fields that form in in deeper subtidal environments (C. Olariu et al., 2012; Longhitano, 2013; Longhitano 41 and Steel, 2017). Cross-bedded sand sheets and dune fields with bimodal rectilinear flow patterns are diagnostic of tidal conditions (e.g. Dalrymple et al., 1992), though they are not formed exclusively in tidal seaways. Figure 15: Schematic model for the deposition of the basal carbonate member in an ebb-dominated tidal seaway. Siliciclastic material is derived from local tidally influenced alluvial fan deltas. Paleocurrents between the Stallard Area Dune Field (D.F.) and Petroglyph Park Dune Field are deflected to the south along the seaway axis. The occurrence and distribution of facies associations FA2 (tide-influenced fan margin) and FA3 (tidal dune field) provide evidence for a tidal seaway setting (Fig. 15). FA2 contains tidal shoreface deposits interbedded with locally-derived sediment that was transferred from local alluvial fans by sheet floods and debris flows. This association closely resembles strait-margin facies described by Longhitano (2013). FA3 records deposition by migrating compound dunes in large subtidal dune fields. Compound dunes in the Stallard area migrated to the east, while those in Petroglyph Park (closer to the basin center) migrated south and parallel to the basin axis (Fig. 15). The change from 42 east-directed to south-directed currents appears to record deflection of the transport direction by axial tidal currents, a process that commonly affects deltas prograding into tidal seaways (Longhitano and Steel, 2013). This process may also be facilitated by bedrock control on tidal currents. We infer that active channels of alluvial fans delivered siliciclastic material into the basin, while inactive areas of fans were inundated by marine water and reworked by tidal flat processes (Fig. 15). 7.2 Buzzards Peak Bouse Localities The location of the marine connection between the southern Blythe Basin and the latest Miocene to early Pliocene Gulf of California has been poorly understood until now. Some studies propose a connection through Midway Wash over the Chocolate Mountains Anticlinorium (CMA) at the Highway 78 pass (Fig. 2; Dillon, 1976; Sherrod and Tosdal, 1991), consistent with broad post-Miocene tilting of the Bouse Formation and uplift along the axis of the CMA adjacent to the San Andreas fault (Olmstead et al., 1973; Beard et al., 2016). Other studies conclude that the southern Bouse Formation formed in a large lake isolated from the ocean, and that Bouse deposits accumulated at modern elevations with no uplift in the past ca. 5 Ma (e.g. Spencer and Patchett, 1997; Spencer et al., 2008, 2013). In this view, the Blythe Basin lake was blocked at its southern end by an inferred paleodam across the modern course of the Colorado River southeast of Buzzards Peak (Fig. 2). Recognition of Bouse tidal deposits at two previously undocumented localities near Buzzards Peak (BP3 and BP4; Figs. 2 and 16 ) provides new constraints on this question. 43 Figure 16: Photos of mixed carbonate-siliciclastic tidal facies in Bouse Formation basal carbonate member near Buzzards Peak (See location in Fig. 17). Interpretations are given in parentheses. A) Vertical succession consisting of: (1) matrix-rich conglomerate with carbonate-rich matrix and clasts of reworked travertine carbonate (alluvial-fan debris flows); (2) poorly sorted, stratified pebble conglomerate (fan- margin sheet floods); (3) well sorted calcerenitic sandstone with 20-cm high tabular cross-bedding, transport to north (shallow-flow, flood-tide dune bedform); and (4) bioturbated sandy calcarenite with relict larger scale cross-bedding (transition to subtidal). B). Close-up of cross-bedded calcarenitic sandstone and bioturbated calcarenite in A. C)~ 1 m high cross-bed set in well sorted sandy calcarenite, transport to south (ebb-tidal dune bedform). D) Close up of cross-bedding in C. 44 Locality BP3 reveals carbonate-rich unstratified conglomerate (Facies S3) and stratified pebble conglomerate (Facies S2) overlain by small-scale tabular cross-bedded calcarenitic sandstone (Facies S4/C4) (Fig. 16A). Cross-beds at this location dip north and record deposition in shallow water by north-flowing currents that we interpret as flood-tidal flow based on comparison to Petroglyph Park. Cross-bedded calcarenitic sandstone is overlain by bioturbated sandy calcarenite with relict cross bedding (Fig. 16B) that records a change to deeper water and colonization by benthic organisms. At locality BP4, south-directed cross-beds in sandy calcarenite are 1 m thick (Fig. 16C,D), similar to Facies C5, and record deposition by subaqueous dunes in deeper water (~5-8 m) by ebb-tide currents. North- and south-dipping cross-bed foresets are consistent with measurements from the Palo Verde Mountains and indicate similar hydraulic conditions. The secular change from alluvial-fan to tidal processes at BP3 and BP4 is also recorded in tidally influenced deposits in the Palo Verde Mts. (this study), Milpitas Wash (Homan, 2014), and southeast of Cibola (O’Connell et al., 2017; Dorsey et al., 2018) (Fig. 2). We conclude this transition records latest Miocene or early Pliocene regional marine transgression when the deposits were at sea level, prior to broad crustal warping that uplifted Bouse carbonates in the Chocolate Mountains to present elevations of ~330 m above sea level (e.g., Beard et al., 2016). 8. Discussion There presently is no consensus regarding the depositional environment for the basal carbonate member of the southern Bouse Formation. Some stratigraphic and sedimentological studies interpret bioclastic carbonate as a record of deposition by tidal 45 processes in a marine embayment or estuary (Buising, 1990; Turak, 2000; O’Connell, 2016; O’Connell et al., 2017; Dorsey et al., 2018; this study). Other studies conclude that southern Bouse carbonate formed in a lake isolated from the ocean (e.g., Spencer and Patchett, 1997; Spencer et al., 2013; Pearthree and House, 2014; Bright et al., 2018a, 2018b), in which case the cross-bedded gravels and coarse-grained bioclastic carbonate would represent deposits of high-energy beach ridges or Gilbert deltas. Below we discuss sedimentary processes and structures of high-energy lakes and their similarities to lithofacies of the southern Bouse basal carbonate member, and evaluate important similarities and differences between them. 8.1 Lacustrine depositional processes Horizontal laminations, wavy-flaser-lenticular bedding and desiccation cracks (Facies C1, C2a-c) are formed by regular changes in current velocity and water depth, which are known to affect lakes. Playa lakes in arid environments can accumulate deposits in sandy mud flats as a result of regular fluctuations in water depth through evaporation and filling (e.g. Ainsworth et al., 2012; Zanor et al., 2012). Perennial lakes such as Lake Michigan and Lake Eyre produce sedimentary structures that are commonly associated with weak tidal processes produced by wind-generated and fluvial currents (Fraser and Hester, 1977; Bye and Will, 1989; Ainsworth et al., 2012). Daily fluctuations in wind velocity and direction in Lake Eyre commonly produce “wind tides” that cause water levels to fluctuate by ca. 5 cm over the course of a day (Bye and Will, 1989). A 5- cm drop in lake level could repeatedly expose and re-submerge mud flats to produce desiccation cracks. Wind-driven currents created by bi-directional winds can form <0.5m thick herringbone crossbedding in lake deposits (Facies C4) (Ainsworth et al., 2012). 46 Similarly, wavy-flaser-lenticular bedding may be created when fluvial currents entering a lake are intermittently slowed by opposing wind-generated currents. Beach-ridge gravel complexes formed at lake margins contain cross-bedding structures similar to those observed in tidal environments, but they are produced almost entirely by wave processes (e.g., Fraser and Hester, 1977; Lichter, 1995; Otvos, 2000; Schuster and Nutz, 2017). Davis et al. (1972) compared ridge and runnel systems in nearshore tidal and lacustrine environments, and found that the morphology of migrating ridges is nearly identical in the two types of environment. Where stream channels enter a lake, fining-upward sequences of tabular to trough cross-beds dip in a lakeward direction and are produced by lateral-accretion point bars in meandering streams (Fraser and Hester, 1977). Beach-ridge complex dunes are often composed of smaller superimposed bedforms, similar to compound bedforms observed in Facies Association 3 (this study). Lakeward migration of eolian beach-ridge dunes is facilitated by high vegetation and a net positive sediment supply to the beach, and/or lowering of lake water level, resulting in shoreline regression (Pye, 1990; Lichter, 1995) High-angle cross-bedding in upper shoreface sands and gravels of Lake Michigan records deposition by reversing longshore currents during storm events that produce bi- polar current directions perpendicular to the shoreline (Fraser and Hester, 1977). Bi- directional paleocurrents have also been recorded in beach ridge gravels associated with the Lake Lahontan Pleistocene highstand (e.g. Blair, 1999). These deposits contain lakeward-dipping, low-angle gravel beds interbedded with landward dipping tabular cross-bedded gravels that represent beach to upper shoreface deposits and washover deposits in back-barrier ponds behind beach ridges. Washover fans with tabular cross 47 bedding are “micro-deltas” that record landward transport of sediment by storm waves breaching a beach ridge (Shaw et al., 2015; Schuster and Nutz, 2017). Beach ridges are the most common deposits of high energy lakes, and near-shore spits and bars are also commonly observed (Schuster and Nutz, 2017). They are produced by longshore currents that produce lateral accretion bars and often contain ridges and coastal dunes formed by shore-normal wind transport (Lichter, 1995; Schuster and Nutz, 2017). 8.2 Tidal versus Lacustrine Origin Although high-energy lakes can produce sedimentary structures similar to those of tidal systems, the deposits of the southern Bouse Formation formed under unique conditions that could not have been generated in a lake. Bimodal currents in lake-margin settings are produced by lateral accretion of point bars at the mouths of streams, reversing wind-driven currents, lateral accretion from reversing long-shore currents, and storm waves breaching beach ridges (e.g., Fraser and Hester, 1977; Blair et al., 1999; Ainsworth et al., 2012; Schuster and Nutz, 2017). Bimodal, rectilinear paleocurrent indicators in the Bouse basal carbonate member are most commonly observed in deeper- water large-scale compound dunes, not shoreline deposits. Bouse compound dunes migrated by forward accretion and display overall coarsening-upward intervals, indicating that they did not form by lateral accretion which most likely would produce fining-upward sequences typical of channel deposition. Thus we conclude that reversing longshore lake currents and meandering channels cannot explain the unique structures and sequences observed in the Bouse basal carbonate member in the Palo Verde Mts. Lakeward-dipping beds and landward-dipping cross-beds on gravelly beach ridges in lakes do record a type of reversing-transport process (e.g., Schuster and Nutz, 48 2017). Low-angle, lakeward dipping beds in well-rounded gravels often are deposited by wave processes such as swash. High-angle, landward dipping tabular cross-beds are generated when storm swells and waves transport gravel over beach ridges into back- barrier lagoons (Shaw et al., 2015). Compound dunes in the Bouse basal carbonate member (this study) are composed of angular to subrounded carbonate grains and lack thick tabular crossbedding. Opposing paleocurrent indicators in the Bouse deposits are found within compound dunes indicating their formation in the same location and time. In contrast, landward-dipping cross-beds in lake-margin gravels are formed separately in space and time from lakeward-dipping low angle cross-beds. Compound dunes in the basal carbonate member average around 4 m thick, whereas tabular cross-bedding produced by reversing winds in lakes are typically about 0.5 meters high (Ainsworth et al., 2012). The largest simple dunes in the basal carbonate member are 1.8 m thick, almost 4 times larger than lacustrine cross-bedding documented by Ainsworth et al. (2012). The large scale of bedforms documented in this study indicate a minimum water depth of 25 meters (e.g. Allen, 1980). At this depth wind-driven current velocities in the Great Lakes are <2.5 cm/s (Beletsky et al., 1999), much weaker than the velocity required to transport grain sizes of Facies C4 and C5 (Allen, 1982; Flemming, 2000). In lacustrine settings, large bedforms are often eolian dunes formed on beach ridges and contain some reversing paleocurrent indicators from changes in wind direction. However, an eolian origin can be ruled out for compound dunes of the southern Bouse deposits because foresets alternate between granule and coarse sand and often contain pebbles in the bottom sets. Grainstones have been documented in lakes 49 (Gierlowski-Kordesch, 2010), but bioclasts in lake deposits are composed of continental fauna, not the dominantly marine fauna observed in the Bouse basal carbonate member. The northern Bouse Formation, which all workers agree formed in a lake (e.g. House et al., 2008; Pearthree and House, 2014; Crossey et al., 2015), notably lacks coarse bioclastic facies and marine fossils. In contrast, the southern Bouse Formation contains both high-energy tidal bedforms (Buising, 1990; Turak, 2000; O’Connell et al., 2017; this study) and marine fauna (Winterer, 1975; Taylor, 1983; McDougall, 2008; McDougall and Miranda-Martínez, 2014). The presence of tidal structures in association with marine fossils is a fundamental criterion that is widely used to confirm a tidal origin in ancient deposits (Ainsworth et al., 2012), and we therefore reject a lacustrine origin for coarse bioclastic facies of the southern Bouse basal carbonate. 8.3 Paleogeographic Reconstruction Figure 17 shows interpreted paleogeography for the southern Bouse tidal seaway based on shoreline modeling from water depth estimates, and observations of diagnostic sedimentary lithofacies, structures, and sequences (Homan, 2014; O’Connell, 2016; O’Connell et al., 2017; Dorsey et al., 2018; this study). This reconstruction includes a marine connection through Midway Wash over the Chocolate Mountains at the Highway 78 pass, as inferred by previous workers (Dillon, 1976; Sherrod and Tosdal, 1991). The reconstructed seaway has an overall north-south orientation with a distinct east-west jog south of the Palo Verde Mts, and displays a geometry conducive to a large tidal range and/or tidal amplification (Fig. 17). We infer that basin subsidence and uplift in flanking ranges was controlled by a diffuse system of transtensional strike-slip and normal faults in the southern part of the Eastern California Shear Zone (e.g., Sherrod and Tosdal, 1991; 50 Figure 17: Paleogeographic reconstruction of the southern Bouse tidal seaway based on data and shoreline estimates presented above (see text for details). Correlation of tidal facies at localities BP3 & BP4 to those in the SE Palo Verde Mountains, Milpitas Wash and Cibola area provides evidence for a marine connection to the paleo-Gulf of California (GoC) over the Highway 78 Pass. Dashed heavy lines are inferred syn-depositional faults, some of which likely were subsurface structures (Sherrod and Tosdal 1991; Richard, 1993; Ricketts et al., 2011; Beard et al., 2016; Dorsey et al., 2017). Plusand mins signs indicate direction (uplift or subsidence) of inferred vertical crustal motions related to syn-basinal fault deformation. Blue outlines indicate present day exposures of the Bouse Formation 51 Richard, 1993; Ricketts et al., 2011; Beard et al., 2016; Dorsey et al., 2017). The paleo- seaway is fairly narrow (<8 km) from localities BP3 and BP4 south to the Highway 78 Pass, and it widens northward from the Stallard Area, producing a funnel-shaped geometry that may have enhanced tidal range and ebb-dominance. The overall geometry is similar to that of the Messina Strait, Italy, and its size is similar to Cook Strait between North and South Island, New Zealand. Tidal seaways and straits are defined as narrow marine connections between two wider bodies of water where tidal processes are dominant (Longhitano and Steel, 2017). The overall geometry of seaways is largely dictated by bedrock topography, but the morphology of coastlines can vary depending on local depositional conditions (i.e. local river input) and local gradient which may be structurally controlled. Our reconstruction shows that coastlines east of the Cibola area had much wider intertidal flats with greater development of tidal channels (O’Connell et al., 2017) than in the southeastern Palo Verde Mountains (Fig. 17). Low energy facies and tidal-channel bar deposits are relatively uncommon in the Palo Verde Mountains, suggesting narrower tidal flats and a steeper basin margin compared to the eastern margin of the seaway. While large alluvial fans provided a broad, low-gradient surface that promoted development of extensive tidal flats on the east side of the tidal seaway, Bouse basal carbonate facies in the Palo Verde Mountains formed directly adjacent to the steep range front and onlap directly onto steep erosional paleotopography. The combination of steep paleotopography and relative paucity of low-gradient alluvial fan surfaces prevented formation of wide tidal flats in the Palo Verde Mountains. 52 8.4 Ebb/Flood Dominance and Asymmetry The magnitude of daily tides is often unequal, and either the flood or ebb current may be stronger (Dronkers, 1986; Kvale et al., 1995; Brown and Davies, 2010). Rarely is the strength of both flood and ebb currents equal. Dominance of a single current (ebb or flood) is dictated by the direction of net sediment transport within a system (Brown and Davies, 2010). These systems can either be ebb- or flood-asymmetrical, where the direction of asymmetry is the current with the highest peak velocity and shortest duration. Asymmetry does not imply dominance of a system, and can change through time as the morphology changes (Brown and Davies, 2010). Although studies of ebb/flood dominance and asymmetry have primarily focused on estuaries, the concepts are applicable to other tidal systems since they do not require fluvial input to be applicable. Voluminous compound dunes in the southern Bouse basal carbonate member migrated in the ebb direction, toward the strait axis (in the Stallard Area) and southward (at Petroglyph Park) toward the late Miocene Gulf of California. These results show that the basal carbonate member accumulated in an ebb-dominant system, consistent with the conclusion of O’Connell et al. (2017). Comparison of bedform thickness between ebb- directed (E, S) and flood-directed (W, N) simple dunes (Figs. 13c, 14c) show that ebb- directed simple dunes are systematically larger than flood-directed dunes, further supporting our conclusion that the basal carbonate member accumulated in an ebb- dominated seaway. However, it is much more difficult to determine tidal asymmetry in the rock record. Although water depth can be estimated from the thicknesses of compound dunes and sedimentary structures (Allen, 1980; this study), estimates of tidal amplitude and surface areas during low and high tides can only be loosely constrained. 53 Studies of estuaries have shown that in the initial stages of formation estuaries have a greater width-averaged depth at high tide than low tide giving rise to a short, fast flood phase and a long, slow ebb phase (flood-asymmetry) (Dronkers, 1986; Pethick, 1994; Townend, 2003; Brown and Davies, 2010). A flood-asymmetric system facilitates accumulation of fine sediments and the build-up of broad intertidal flats along the margins. Buildup of shallow intertidal flats creates deep, narrow subtidal channels, and a threshold is crossed where the width-averaged water depth during high tide is reduced, the ebb duration decreases, and peak ebb velocity increases, changing the system to ebb- asymmetric (Kang and Jun, 2003; Townend, 2003; Fortunato and Oliveira, 2005; Moore et al., 2009; Brown and Davies, 2010). Faster currents during the ebb phase promote erosion of intertidal flats and net export of the sediment from the system. An estuary may remain in dynamic equilibrium over time through feedback driven by the buildup and erosion of intertidal flats and subtidal channels. Our paleogeographic reconstruction (Fig. 17) provides some insight into the asymmetry of the southern Bouse Formation. The eastern margin of the seaway was dominated by broad intertidal flats, whereas the western margin had significantly narrower intertidal flats adjacent to a steep basin margin. While this difference may reflect structurally controlled asymmetry of topography across the seaway, it could also be related to a change from flood-asymmetry to ebb-asymmetry. Pethick (1994) suggested that an estuary may change asymmetry about every 100 years to maintain dynamic equilibrium, and this basin may have also fluctuated between flood and ebb asymmetries. Basin subsidence and relative sea-level rise (Dorsey et al., 2018) allowed for aggradation of tidal flats along the margins and formation of deep subtidal 54 environments along the axis of the tidal seaway. Large bedforms require deep water (Allen, 1980) and, to lesser extent, fast current velocities to transport large volumes of sediment. Ebb-directed simple dunes documented in this study are larger than flood- directed simple dunes (Figs. 13c, 14c), which requires deeper water and/or faster velocities for the ebb-directed bedforms. Because the simple dunes are found within compound dunes that formed at ca. 25 m depth, it is unlikely that water depth was the limiting factor in simple dune thickness. Thus, the difference in scale of ebb- and flood- directed bedforms probably was controlled by a difference in peak velocity. We speculate that the ebb phase was short but with higher peak velocities that drove larger bedforms and a larger-volume sediment transport compared to a longer but slower flood phase. Although the tidal asymmetry cannot be quantified for the southern Bouse Formation, the available data and observations suggest deposition in an ebb-dominated, ebb-asymmetric tidal system. 9. Conclusions This study examined sedimentary lithofacies, paleocurrent directions, and architecture of large-scale bedforms in the basal carbonate member of the southern Bouse Formation in the Palo Verde Mountains, southeastern California. Our results lead to the following conclusions: (1) Bi-modal, rectilinear paleocurrent data reveal dominant transport to the east and south with a subordinate current in the opposing directions. 55 (2) Cross-bedding records migration by forward accretion, not lateral accretion, indicating that the bi-modality of paleocurrents reflects changes in current direction rather than lateral migration of bars or meandering channels. (3) Large-scale compound dunes formed at ca. 25 m depth, well below the depth at which wind-driven currents in lakes become incapable of transporting coarse bioclastic sediment. (4) Intertidal flat and alluvial fan deposits are interbedded at the basin margin, a feature diagnostic of tidal strait and seaway margins. (5) Large-scale compound dunes are only found near the basin axis, which we interpret to be a subtidal zone where strong axial currents formed large dune fields. The data and results of this study reveal a suite of depositional processes that are inconsistent with deposition in a lacustrine environment, but are consistent with abundant marine fauna in the southern Bouse Formation. We therefore conclude that the basal carbonate member accumulated in an ebb-dominated tidal seaway during regional marine transgression. Our paleogeographic reconstruction includes a marine connection over the Chocolate Mountains through the Highway 78 pass, providing new evidence for broad post-Miocene uplift in the lower Colorado River region. If the Chocolate Mountains had been at or near their present elevation during deposition of the southern Bouse Formation, a marine connection would not have been possible and strong tides could not have existed in this basin. Thus, much of the uplift to present-day elevations must have occurred since late Miocene or early Pliocene time. These results highlight the value of integrative 56 sedimentology and stratigraphic analysis in reconstructing depositional paleoenvironments, and provide important constraints on the timing and magnitude of long-wavelength vertical crustal motions adjacent to an active transform plate boundary. 57 APPENDIX A MEASURED SECTION LOCATIONS (DATUM: WGS84) Section Latitude Longitude Elevation (m asl) KG1 33.32039 -114.73746 83 KG2 33.31437 -114.74540 93 KG3 33.31295 -114.74428 83 KG4 33.31183 -114.74389 82.95 KG5 33.31183 -114.74289 81.75 KG6 33.31179 -114.74217 78.5 KG7 33.29614 -114.76691 119.4 KG8 33.29594 -114.26629 119 KG9 33.29575 -114.76555 115.6 KG10 33.29534 -114.76462 119 KG11 33.29489 -114.76685 123 KG12 33.29262 -114.76450 118 KG13 33.29098 -114.75822 107.25 KG14 33.29202 -114.76241 110 KG15 33.30200 -114.76243 121 KG16 33.30159 -114.76090 115 KG17 33.30159 -114.76051 112 KG18 33.30138 -114.75999 110.5 KG19 33.30075 -114.75938 107.6 KG20 33.29731 -114.75668 104.4 KG21 33.29673 -114.75426 97 KG22 33.29639 -114.75136 91 KG23 33.30758 -114.75134 94.5 KG24 33.30721 -114.74867 93 KG25 33.30688 -114.74545 89 KG26 33.30709 -114.74813 94 PVM-1 33.29730 -114.76793 131 58 PVM-2 33.29698 -114.76732 131 PVM-3 33.29609 -114.76482 130 PVM-4 33.30378 -114.75709 112 PVM-5 33.29330 -114.76836 123 PVM-6 33.29614 -114.76704 125 PVM-7 33.29603 -114.76652 124 PVM-8 33.29617 -114.76613 123 PVM-9 33.29606 -114.76577 122 PVM-10 33.29542 -114.76517 122 PVM-11 33.29160 -114.76213 111 PVM-12 33.29546 -114.75305 95 PVM-13 33.31554 -114.74169 86 PP-1 33.33668 -114.72139 74 PP-2 33.33668 -114.72122 76 SR-1 33.35899 -114.72660 77 SR-2 33.36895 -114.72639 75 SR-3 33.35910 -114.72628 75 SR-4 33.35553 -114.72463 74 SR-5 33.35162 -114.72609 68 59 APPENDIX B TABULATED MEASURED SECTIONS Section KG-1 Height in Description section (m) 0-3.4 Poorly sorted sandy pebble conglomerate with angular casts and trough crossbedding. Trough axes oriented 70°. Troughs 0.3-0.5m thick.Unit: Miocene Conglomerate 3.4-3.8 Moderately sorted sandy pebble conglomerate with surrounded clasts a trough crossbedding. Unit: Reworked Conglomerate (Bouse) 3.8-4.4 Well sorted, fine grained sandy grainstone. Thins to the east due to erosion.Unit: basal carbonate member 4.4-5.6 Horizontally bedded pebble conglomerate with sandy matrix. Sparse barnacle rich medium grained grainstone interbeds. Erosional boundary with underlying unit. Thins eastward into condensed unit. Unit:Basal Carbonate Member 5.6-6.7 Interbedded horizontally stratified fine-grained sandy grainstone and sandy pebble conglomerate. Grainstone beds: 0.2-0.25 m thick; Conglomerate beds: 0.2-0.25m thick; Unit: basal carbonate member 6.7-7.4 Calcisiltite with horizontal laminations and minor soft sed deformation. Unit: basal carbonate member 7.4-7.6 Travertine interbed with small bioherms (<1m across). Passes eastward into fine to medium-grained grainstone; Unit: basal carbonate member 7.6-8 Calcisiltite with horizontal laminations and minor soft sed deformation. Unit: Bioclastic Unit of Basal Carbonate Member 8.0-8.2 Travertine interbed with small bioherms (<1m across). Passes eastward into fine to medium-grained grainstone; Unit: basal carbonate member 8.2-10.0 Interbedded calcisiltite and siliciclastic-rich calcisiltite with horizontal laminations. Unit: Bioclastic Unit of the basal carbonate member. 10.0-12.2 Interbedded coarse- to very coarse-grained grainstone and fine- grained grainstone. Unit: basal carbonate member. 12.2-13.1 Pebbly fine-grained grainstone with siliciclastic pebbles; Structureless. Basal 0.2m contains travertine rip up clasts. Unit: basal carbonate member. 60 13.1-15.6 Horizontally bedded, very coarse-grained gravestone with abundant barnacle and shell fragments. Individual beds range from 0.03-0.1m thick. Unit: Bioclastic unit of basal carbonate member. 15.6-19.9 Poorly sorted, angular pebble-cobble conglomerate. Quaternary Gravel Section KG-2 Height in Description section (m) 0-7.4 Poorly sorted, moderately cemented pebble to cobble conglomerate with siliciclastic matrix; No discernible structures; Unit: Miocene Conglomerate. 7.4-7.5 Moderately sorted cobble conglomerate with sub=rounded clasts; cobble lag; Unit: basal carbonate member 7.5-7.6 Moderately sorted pebbly granule conglomerate with <30% carbonate in matrix. Unit: basal carbonate member. 7.6-8.7 Horizontally bedded, well sorted, very fine- to fine-grained grainstone with 3-5cm interbreeds of calcisiltite; Wavy bedding and rippled tops present in grainstone beds; Unit: basal carbonate member. 8.7-9.2 Poorly sorted, angular, pebble to cobble conglomerate; Quaternary Gravel Section KG-3 Height in Description section (m) 0.0-5.1 Poorly sorted, sandy pebble to cobble conglomerate with angular to sub- angular clasts; trough cross-bedded; cross-beds 0.3m thick with axes oriented 172°; Unit: Miocene Conglomerate 5.1-6.0 Poorly sorted, granule to pebble conglomerate with weak horizontal stratification; sandy matrix supported; Unit: Miocene Conglomerate 6.0-6.1 Well sorted, very fine-grained sandy grainstone with poorly exposed tabular cross-bedding 6.1-6.8 Moderately sorted, pebbly, granule conglomerate with 30cm thick bi- directional tabular cross-bed sets; well rounded clasts; Unit: Reworked conglomerate. 61 6.8-7.1 Massive lime mud; Unit: basal carbonate member 7.1-8.3 Interbedded very fine to fine-grained grainstone with wavy to planar bedding. Individual beds range from 3-5cm thick. Unit: basal carbonate member Section KG-4 Height in Description section (m) 0.0-5.7 Poorly sorted, pebble to cobble conglomerates with infrequent small boulders; angular-subangular clasts; trough cross-bedding throughout, but is absent in upper 40cm; Unit: Miocene Conglomerate 5.7-7.0 Poorly sorted, pebble to cobble conglomerate with <20% carbonate in the matrix; Horizontal to low-angle stratification; Unit: Reworked conglomerate 7.0-9.6 Interbedded calcisiltite and very fine-grained calcarenite; horizontal to wavy-falser bedding; <10% siliciclastics; individual beds range from 1- 5cm; Unit: Basal carbonate member 9.6-11.0 Horizontally bedded, fine grained calcarenite with <10% siliciclastics. Unit: Basal carbonate member. 11.0-11.1 Pebble conglomerate; Quaternary Gravel Section KG-5 Height in Description section (m) 0.0-1.7 Moderately to poorly sorted, sub rounded, pebble to cobble conglomerate; inverse grading with large boulders in upper 40cm; Unit: Miocene conglomerate 1.7-2.5 Moderately sorted; normally graded with small boulders at base; pebble to cobble conglomerate with weak bi-directional cross-bedding; Minor carbonate in matrix; Unit: Reworked conglomerate 2.5-2.9 Massive lime mud bed; Unit: Basal carbonate member 2.9-4.4 Interbedded calcisiltite and very fine-grained grainstone; horizontal to wavy bedding; wave ripple surfaces on grainstone beds; individual beds range from 1-5cm; Unit: Basal carbonate member 62 4.4-6.4 Horizontally bedded, granular grainstone; abundant barnacles, mollusks and rhodolite fragments; grades laterally eastward into poorly cemented lime mud; Unit: Basal carbonate member 6.4-7.6 Fine to medium-grained fossiliferous sandy grainstone; weak bidirectional crossbedding and rippled surfaces; ~40% siliciclastics; grades lateral eastward into poorly cemented lime mud; Unit: basal carbonate member 7.6-8.3 Poorly sorted pebble conglomerate; Quaternary Gravel Section KG-6 Height in Description section (m) 0.0-0.1 Very fine-grained silty grainstone; abundant reed casts; Sample GB-4 0.1-0.4 Fine-grained sandy grainstone with basal cobble lag; 50% siliciclastics; Unit: Basal carbonate member. 0.4-0.7 Poorly sorted, sandy cobble conglomerate; surrounded clasts; clast supported; Unit: Basal carbonate member 0.7-1.2 Well sorted, sub-rounded, very coarse-grained sandy grainstone; horizontal to low-angle stratification; Unit: Basal carbonate member. 1.2-1.7 Well to moderately sorted, medium- to coarse-grained sandy grainstone; abundant wave ripple laminations; ostracodes and shell fragments common; thalassinoides burrows present at base of unit; marine gastropod casts and molds abundant; Unit: Basal carbonate member. 1.7-2.2 Poorly sorted, sub-rounded, cobble conglomerate; inversely graded from very coarse sand at base to cobbles; unit pinches out 15m to the east; Unit: Basal carbonate member 2.2-3.3 Poorly sorted, pebble to cobble conglomerate; rounded to subangular clasts; inversely graded from pebbles at base to boulders at upper boundary; Unit pinches out 15m to the east: <10% carbonate in matrix; Unit: Basal carbonate member. 3.3-3.8 Massive lime mud with weakly defined bedding; drapes over underlying large boulders; Unit: Basal carbonate member 3.8-5.3 Interbedded calcisiltite and very fine-grained grainstone; >80% carbonate; wavy to planar bedding; Individual beds range from 2-8cm; lower 0.5m of unit appears to drape over mounds created in underlying unit; Unit: Basal carbonate member 63 5.3-5.5 Moderately sorted, granular grainstone; clasts entirely made of barnacle and mollusk fragments; Unit: Basal carbonate member 5.5-6.0 Horizontally laminated carbonate paper shale; highly fissile; Unit: Upper marl of basal carbonate member. 6.0-6.1 Quaternary Gravel Section KG-7 Height in Description section (m) 0.0-2.2 Poorly sorted, pebble to cobble conglomerate with horizontal stratification; angular to subangular clasts; alternates between clast and matrix supported beds (2-10 cm thick); clast supported intervals have clast imbrication with imbrication dipping towards 301°; Unit: Miocene Conglomerate 2.2-2.3 Very fine- to fine-grained sandy grainstone; <20% siliciclastics; structureless; Unit: Basal carbonate member 2.3-3.6 Poorly sorted, pebble to cobble conglomerate; horizontal bedding; ungraded; subangular clasts; clast imbrication dips toward 304°; Unit: Basal carbonate member 3.6-3.9 Structureless, very-fine- to fine-grained grainstone; abundant rhodoliths and Battalaria fossils; >85% carbonate; Unit: Basal carbonate member. 3.9-4.6 Interbedded calcisiltite and very fine- to fine-grained grainstone with horizontal stratification; calcisiltite beds are 1-3 cm thick; grainstone beds are 5 cm thick; Unit: Basal carbonate member 4.6-6.6 Interbedded lime mud and fine-grained grainstone; wavy bedding to horizontal stratification; lime mud beds are <1 cm thick; grainstone beds are 3-5 cm thick; Unit: Basal carbonate member 6.6-7.3 Poorly sorted, pebble to cobble conglomerate with calcareous matrix; weak cross-bedding; angular to subangular clasts; Unit: Basal carbonate member 7.3-8.8 Poorly sorted, unstratified, pebble to cobble conglomerate; Quaternary Gravel 64 Section KG-8 Height in Description section (m) 0.0-0.4 Poorly sorted, pebble conglomerate; angular clasts; structureless; ungraded; 0.4-0.5 Well sorted, very fine-grained grainstone with minor siliciclastic component (<15%); Unit: Basal carbonate member 0.5-0.6 Well sorted, granule-sized grainstone; abundant mollusks and barnacles; Unit: Basal carbonate member 0.6-1.6 Poorly sorted, granule to pebble conglomerate; inversely graded with large cobbles in upper 20 cm; clasts are rounded; Unit; Basal carbonate member. 1.6-1.9 Well sorted, fine-grained sandy grainstone with no internal bedding; gastropod fossils and thalassinoides burrows common; Unit: Basal carbonate member 1.9-2.7 Interbedded calcisiltite and very fine- to fine-grained grainstone; wavy to planar stratification; individual beds range from 1-5 cm thick; Unit: Basal carbonate member 2.7-4.7 Inter bedded lime mude, calcisilitite, and very fine- to fine-grained sandy grainstone; wavy, flaser, and planar bedding throughout; individual beds range from 2-4 cm; Unit: Basal carbonate member 4.7-9.8m Poorly sorted, weakly cemented, sandy, pebble conglomerate: Quaternary gravel. Section KG-9 Height in Description section (m) 0.0-1.0 Horizontally bedded calcisiltite with minor interbeds of very fine-grained grainstone; wavy bedding uncommon; Unit: Basal carbonate member 1.0-1.2 Calcisiltite with single coarse-grained fossiliferous grainstone bed; grainstone interbed is 6 cm thick; Unit: Basal carbonate member 1.2-1.6 Interbedded planar laminated calcisiltite and wavy bedded very fine grained grainstone; Unit: Basal carbonate member 65 1.6-2.0 Structureless calcisiltite that coarsens upward into a coarse-grained grainstone; wavy and planar laminations common in grainstone; mollusks and barnacles common; Unit: Basal carbonate member 2.0-2.3 Coarse grained, fossiliferous pebbly grainstone with no distinct internal structures; pebbles concentrated in upper 10 cm; Unit: Basal carbonate member 2.3-3.0 Tabular cross-bedded fossiliferous coarse-grained grainstone; forests average between 10-20 cm thick and dip 22-30° towards 125*; background dip is 7° to 130°; siliciclastic pebbles concentrated in lower 10 cm; Unit: Basal carbonate member 3.0-7.6 Horizontally to wavy bedded, very coarse-grained to granular fossiliferous grainstone with 20-30 cm thick interbeds of poorly sorted , angular pebble to cobble conglomerate; conglomerate matrix ranges from 20-60% carbonate; Upper 30 cm of unit contain bi-directional tabular cross beds (20-30 cm thick) oriented towards 130° and 310°; Unit: Basal carbonate member 7.6-13.4 Quaternary gravel and covered section; gravel appears to have eroded away Upper bioclastic member. Base of gravel (20 cm) is well cemented and may possibly be remnant of UBM. Section KG-10 Height in Description section (m) 0.0-0.3 Fine-grained grainstone with planar to wavy bedding; top of bioclastic unit 0.3-0.7 Green claystone; highly fissile; planar laminations; pale green color 0.7-1.1 Structureless, well sorted, fine-grained grainstone; few shell fragments; 1.1-1.6 Green claystone; highl fissile with planar bedding; dark green in lowest 5 cm; orange weathering in cracks; possible DCL; 1.6-1.7 Structureless, well sorted, fine-grained grainstone; no fossils present 1.7-5.0 Red mudstone with rare siltstone interbeds; planar laminations; highly fissile; Unit: Siliciclastic member 5.0-5.5 Moderately sorted, coarse grained sandy grainstone with abundant barnacle and mollusk fragments; structureless; 5.5-7.3 Red mudstone with minor silt; planar laminations; fissile; Unit siliciclastic member; 66 7.3-8.3 Coarse-grained sandy grainstone with planar to wavy bedding and abundan barnacles, mollusks, and coralline red algae; poorly preserved tabular cross- bedding visible; Unit: Upper bioclastic member 8.3-10.2 Quaternary gravel/cover Section KG-11 Height in Description section (m) 0.0-1.0 Moderately sorted, fine- to medium-grained grainstone with abundant mollusk fragments and rhodoliths; planar and wavy bedding common; uppermost surface exposes poorly preserved cross-beds; similar to dancefloor of the Cibola area; top of the bioclastic unit 1.0-2.8 Covered section; massive lime mud out of section projects into covered interval. 2.8-3.9 Massive lime mud with no distinct bedding or internal structures; Upper Marl 3.9-5.1 Carbonate paper shale with millimeter thick laminations; paper shale is interbedded every 40 cm by 10 cm thick interbeds of massive lime mud; background dip is 5° to 134°; Upper Marl 5.1-5.3 Coarse-grained to granular sandy grainstone with planar bedding and abundant shell fragments; Upper bioclastic member 5.3-5.8 Planar bedded, granule to pebble conglomerate with mixed siliciclastic and carbonate matrix; siliciclastic pebbles and granules are subrounded to rounded; shell fragments and coralline red algae fragments are abundant; Upper bioclastic member 5.8-6.0 Planar bedded, moderately sorted, very coarse-grained to granular sandy grainstone with abundant mollusk and barnacle fossils; individual beds are about 1 cm; Upper bioclastic member 6.0-6.6 Horizontally bedded, poorly sorted, coarse- to very coarse-grained pebbly grainstone; carbonate grains are almost entirely shell fragments; individual beds are 5 cm thick; coarse-grained beds have fewer shell fragments; 50% carbonate in matrix; Upper bioclastic member 6.6-8.0 Poorly sorted, rounded, granule to pebble conglomerate with calcareous matrix; matrix is >60% carbonate; shell fragments and coralline red algae common; Upper bioclastic member 67 8.0-9.8 Poorly sorted, weakly horizontal to low angle bedded, pebble to cobble conglomerate with mixed matrix (>50% carbonate); sub angular to angular clasts; matrix is very coarse-grained sandy grainstone; Upper bioclastic member 9.8-12.8 Poorly sorted, planar bedded, pebble to cobble conglomerate with minor boulders; individual beds range from 2-20cm; carbonate component of matrix in beds varies but does not fall below 20%; matrix supported; angular to subangular clasts; Upper bioclastic member 12.8-13.7 Quaternary Gravel Section KG-12 Height in Description section (m) 0.0-4.9 Interbedded fissile red mudstone and siltstone with minor sand interbeds; sandy beds are Colorado River derived sands; sand beds do not exceed 3 cm in thickness 4.9-5.0 Well sorted, very fine- to fine-grained Colorado River sandstone; unit thickens to the NW to over 1.5 meters thick; meter scale trough cross-bedding observed; trough axis oriented 140°; 5.0-12.4 Well sorted, well rounded, very fine- to fine-grained Colorado River sandstone; trough crossbedding and ripple cross laminations are abundant; poorly cemented. 12.4-12.6 Coarse-grained, planar bedded pebbly sandy grainstone with abundant coralline red algae fragments; Upper bioclastic member 12.6-13.3 Planar bedded, coarse-grained pebbly sandy grainstone with shell fragments; 60% carbonate; Upper bioclastic member; 13.3-15.0 Poorly sorted, subangular pebble to cobble conglomerate; inversely graded from pebbly, coarse-grained grainstone (30% siliciclastics) with hummocky cross stratification at the base to a clast supported pebble to cobble conglomerate (>80% siliciclastic in matrix) in the upper 0.7 m; carbonate content decreases upwards to zero; Upper bioclastic member 15.0-17.0 Poorly sorted, angular pebble conglomerate; transitional with underlying unit; no carbonate in matrix; clast supported; Tfg2; 17.0-17.2 Quaternary Gravel 68 Section KG-13 Height in Description section (m) 0.0-6.3 Planar laminated, red mudstone; highly fissile until uppermost 1 m when occasional 10-20 cm thick massive mudstone interbeds appear. 6.3-6.5 Massive siltstone with ~10% carbonate 6.5-9.0 Poorly sorted, subangular, sandy pebble to cobble conglomerate; matrix supported; planar bedding throughout; coarsens upward into sandy cobble conglomerate; matrix is <20% carbonate shell fragments; Upper bioclastic member 9.0-9.5 Poorly sorted, subangular, sandy pebble conglomerate; ,matrix supported; no internal structures; Upper bioclastic member 9.5-11.2 Poorly sorted, coarse-grained pebbly sandstone with weak horizontal stratification; coarsens upward into a poorly sorted, sandy pebble to cobble conglomerate with horizontal stratification; <20% carbonate; Upper bioclastic member 11.2-13.2 Structureless, well sorted, fine- to medium-grained sandstone with minor silt; >10% carbonates; Upper bioclastic member 13.2-15.2 Weakly horizontally laminated poorly sorted, pebble to cobble conglomerate; angular to sub-angular clasts; erosional contact with underlying unit; no carbonate in matrix; moderately to weakly cemented; Tfg2 Section KG-14 Height in Description section (m) 0.0-4.0 Planar laminated, fissile red mudstone with minor 5 cm thick calcisiltite interbeds; upper 10cm is silt-rich; Siliciclastic member 69 4.0-4.3 Very fine- to fine-grained Colorado River sandstone with climbing ripples; well sorted; rounded; Siliciclastic member 4.3-4.5 Silty red mudstone; highly fissile 4.5-4.7 Very fine- to fine-grained Colorado river sandstone with asymmetrical ripple laminations throughout; quite silty; 4.7-4.9 Silty red mudstone; highly fissile 4.9-7.7 Moderately sorted, silty, very fine- to fine-grained Colorado River sandstone with weakly preserved centimeter scale ripples; individual laminations are 1-2 mm thick; poorly cemented 7.7-10.7 Interbedded silty, very fine- fine to fine grained Colorado River sandstone and massive red mudstone; Individual beds range from 10-40 cm 10.7-11.9 Well sorted, fine-grained Colorado River sandstone with abundant climbing ripples and asymmetric ripple laminations; 11.9-12.8 Moderately to poorly sorted, pebble to cobble conglomerate; low angle crossbedding throughout; horizontally bedded otherwise; clast imbrications dip towards 307°<10% carbonate in matrix; coralline red algae; Upper bioclastic member 12.8-15.7 Poorly sorted, subrounded to subangular, pebble to cobble conglomerate; no carbonate fragments; weak, sub horizontal stratification; weakly cemented; Tfg2? Section KG-15 Height in Description section (m) 0.0-0.9 Very fine- to fine-grained crystalline travertine bioherms; spaces between mounds are filled by calcisilitite; Basal carbonate member 0.9-2.5 Interbedded calcisiltite and very fine-grained grainstone; individual beds range from 1-3 cm thick; 1-2 mm thick lime mud interbeds also present; flaser to wavy bedding common; planar bedding present throughout; Basal carbonate member; Background dip: 4° towards 128° 70 2.5-2.9 Fine-grained grainstone with abundant bivalve fragments and gastropod shells; very dense and well cemented in patches (silicification?); Sample GB6; Basal carbonate member 2.9-3.5 Barnacle and bivalve rich, very coarse-grained to granular grainstone with minor coarse-grained grainstone interbeds; 5 cm tall foresets dipping 12* towards 134°; planar to wavy beds on uppermost 10 cm; Basal carbonate member 3.5-6.2 Quaternary Gravel Section KG-16 Height in Description section (m) 0.0-2.3 Planar bedded calcisiltite with minor 2 cm thick interbeds of very fine- grained grainstone; beds have planar laminations and centimeter scale wave ripple laminations throughout; lenticular bedding is sparse; Basal carbonate member 2.3-8.7 Very coarse-grained to granular, fossiliferous grainstone; tabular cross- bedding showing bidirectional currents; Foresets dip 12° towards 120°/ 16° towards 309°; bedset thicknesses range from 10-20 cm for both current directions; bottom sets are planar to wave rippled and are almost entirely composed of fossils; Charophyte casts are discontinuous along bedding planes and are absent in the upper 4 meters; Basal carbonate member 8.7-12.6 Quaternary Gravel 71 Section KG-17 Height in Description section (m) 0.0-1.2 Interbedded lime mud and very fine-grained grainstone with prominent wavy bedding; lime mud interbeds range from 1mm to 1cm; fines upward to become dominated by calcisiltite; lenticular and flaser bedding common in uppermost 20 cm; Basal carbonate member 1.2-1.5 Planar bedded, granular, fossiliferous grainstone with no internal bedding; Basal carbonate member 1.5-2.7 Fissile, poorly cemented carbonate paper shale with millimeter thick laminations; Upper marl 2.7-2.9 Moderately sorted, medium- to coarse-grained sandy grainstone with minor bivalve shell fragments; 2.9-3.1 Highly fissile pale green clay stone 3.1-4.3 Fissile red mudstone with minor thin (2-3 cm) siltstone interbeds 4.3-6.9 Quaternary Gravel Section KG-18 Height in Description section (m) 0.0-0.6 Fissile carbonate paper shale with 1 mm thick laminations; background dip is 6° towards 71° (possible local control) 0.6-0.7 Structureless, medium- to coarse-grained sandy grainstone; 0.7-1.2 Fissile pale green claystone with rare orange discoloration; possible DCL? 1.2-4.5 Thinly bedded red mudstone with minor 5 cm thick interbeds of massive red mudstone; unit has abundant white, concretions that appear to be carbonate 4.5-5.3 Quaternary Gravel 72 Section KG-19 Height in Description section (m) 0.0-5.9 Highly weathered fissile red mudstone with silt interbeds (5 cm thick); Root traces visible in upper 10-20cm 5.9-6.0 Poorly sorted, clast supported, cobble conglomerate; subangular clasts; 6.0-6.2 Poorly sorted, clast supported, pebble conglomerate; subangular clasts; 6.2-6.4 Moderately sorted, pebbly granule conglomerate with a fine-grained sandy matrix; tabular cross-bedding with foresets (20 cm thick) dipping 16° towards 203°; subrounded to subangular clasts 6.4-8.2 Poorly sorted, granule to pebble conglomerate with medium-grained sandy matrix; unit is clast supported at base and matrix supported at the top; subrounded to subangular clasts; carbonate in matrix decreases upwards from 20% to <5%; Upper bioclastic member 8.2-12.7 Poorly sorted, angular to subangular; clast supported pebble to cobble conglomerate; weakly cemented; internal structures are weakly developed horizontal stratification; carbonate content decreases upwards from 5% to 0%; transition from upper bioclastic member to Tfg2 Section KG-20 Height in Description section (m) 0.0-1.6 Silty, very fine-grained Colorado River sand; well sorted, well rounded, poorly consolidated; possible soft sediment deformation, some convolute bedding 1.6-4.1 Fissile red mudstone and siltstone; three thin (1-3 cm thick) interbeds of very fine-grained Colorado River sand in upper 60 m; 73 4.1-7.9 Trough cross bedded and ripple cross laminated, very fine-grained Colorado River sandstone; poorly consolidated; ripples indicate flow towards 287°; ripple height is 2 cm; 7.9-9.3 Fine- to medium-grained colorado river sandstone with abundant climbing ripples; trough crossbedding present but poorly preserved due to poor consolidation; ripples indicate flow towards 240° 9.3-9.5 Structureless siltstone interbed; thickens slightly towards the east; 9.5-9.7 Fine-grained Colorado River sandstone with abundant climbing ripples; background dip is 3° towards 115° 9.7-10.3 Siltstone with weakly developed horizontal laminations 10.3-13.4 Poorly sorted, subrounded, matrix supported, horizontal to low angle bedded , pebble to cobble conglomerate with a medium-grained sand matrix; carbonate content is ~30% and is made of shell fragments and coralline red algae; carbonate content decreases to <10% near the top of the unit; a concentration of cobbles is observed in the upper 40 cm of the unit; Upper bioclastic member 13.4-19.4 Poorly sorted, angular to subangular, clast supported, pebble to cobble conglomerate with a medium sand matrix; no carbonate; erosional basal contact with underlying unit; poorly consolidated; Tfg2. Section KG-21 Height in Description section (m) 0.0-9.7 Fissile red mudstone with interbedded siltstone; siltstone interbeds range from 5-8 cm thick; 9.7-11.2 Very fine-grained Colorado River sandstone with weak planar bedding; minor ripple laminations throughout; ripples are 2 cm thick 74 11.2-16.2 Poorly sorted, subrounded, planar bedded, matrix supported pebbly conglomerate; matrix composition is <50% carbonate in first meter, decreases to <30% in the next 3 m, and is <10% in the upper 40 cm; coralline red algae fragments common in the lower two meters 16.2-17.6 Quaternary Gravel Section KG-22 Height in Description section (m) 0.0-8.2 Fissile red mudstone; interbedded with siltstone and very fine-grained Colorado River Sandstone in the uppermost meter; bedding becomes increasingly convolute and deformed to the NE; individual silt and sand beds are no greater than 5 cm thick. 8.2-11.0 Moderately sorted, subrounded, clast supported granule conglomerate with minor pebbles and cobbles; planar bedding and tabular cross-bedding is observed; cross-beds are 30 cm thick and dip 22° towards 120°; granular reactivation surfaces can be found on many foresets; coralline red algae fragments are abundant in the lower 2 meters; carbonate in matrix is 40%; Upper bioclastic member 11.0-14.6 Poorly sorted, subangular to subrounded, clast supported granule to pebble conglomerate with minor cobbles; mostly horizontally stratified, with rare tabular cross-beds; cross-bedding has the same orientation as underlying unit; carbonate in matrix is <10%; coralline red algae fragments are not present 75 Section KG-23 Height in Description section (m) 0.0-7.2 Poorly sorted, subangular to rounded, boulder rich, pebble to cobble conglomerate; matrix supported; 30-40 cm thick trough crossbreeds throughout; axis of trough oriented 95° on vertical face oriented 50°; no carbonates; well cemented; Miocene Conglomerate 7.2-7.4 Quaternary Gravel Section KG-24 Height in Description section (m) 0.0-1.8 Horizontally stratified, subangular to subrounded, poorly sorted, pebble to cobble conglomerate; matrix supported; no carbonate in matrix; upper 20 cm is a clast supported cobble lag; with almost no matrix; Miocene Conglomerate 1.8-2.1 Highly silicified travel tine with single 30cm tall bioherm; travertine thickness on either side of bioherm is 10 cm; battilaria fossils common; sample GB7 2.1-2.5 Poorly sorted, subrounded, pebble to cobble conglomerate with no distinct bedding; ungraded; 2.5-2.8 Massive calcisiltite with abundant mollusk and battilaria fossils 2.8-3.3 Interbedded calcisiltite, lime mud, and very fine-grained sandy grainstone; lime mud beds are 1cm thick; calcisiltite and sandy grainstone beds are 1- 3cm thick and display wavy bedding; 3.3-7.9 Very fine-grained Colorado River derived sand with minor granitic granule sized gravel in patches. Chemehuevi Fm. 7.9-9.1 Quaternary Gravel 76 Section KG-25 Height in Description section (m) 0.0-2.3 Interbedded, structureless very fine-grained Colorado River sand and red mudstones; tilted and deformed by large scale soft sediment deformation; bedding is increasingly convolute to the west; Siliciclastic member; 2.3-4.6 Tabular cross-bedded, moderately sorted, rounded to subangular, matrix supported, pebbly granule conglomerate; cross-beds are 20 cm thick and indicate transport towards 223; <20% carbonate in matrix; Upper bioclastic member 4.6-5.8 Poorly sorted, angular to subangular, horizontally stratified, matrix supported pebble conglomerate with minor cobbles; no carbonates present; Tfg2 Section KG-26 Height in Description section (m) 0.0-0.2 Massive lime mud 0.2-1.6 Horizontally stratified and wavy-flaser-lenticular bedded calcisiltite, very fine-grained grainstone, and lime mud; lime mud beds are <1 cm thick; silt and grainstone beds are 3-5 cm thick; background dip is 5° towards 108° 1.6-5.2 Silty, very fine-grained Colorado River sands; massive to weakly crossbedded; trough crossbedding not visible due to cover, but is likely; 5.2-6.6 Quaternary Gravel 77 Section PVM-1 Height in Description section (m) 0.0-2.4 Weakly stratified, poorly sorted, granular to pebbly grainstone with lenses of moderately sorted pebble to cobble conglomerate in channels; channels range from 0.1-0.4 m tall and 1.5m wide; Basal carbonate member 2.4-2.8 Unstratified, ungraded cobble conglomerate; 2.8-4.8 Moderately to poorly sorted, pebble to boulder conglomerate with no internal structures; cobbles and boulders are concentrated in pockets 4.8-7.0 Horizontally stratified pebbly grainstone with lenses of moderately to poorly sorted pebble to boulder conglomerate that form elongate bodies up to 30 cm thick; conglomerate clasts are angular to subrounded; matrix in conglomerate is >50% carbonate 7.0-8.2 Quaternary Gravel Section PVM-2 Height in Description section (m) 0.0-0.4 Poorly sorted, medium to very coarse-grained pebbly sandstone with minor cobbles; weakly stratified; Miocene Conglomerate 0.4-1.1 Very fine-grained grainstone and calcisiltite with planar to wave ripple laminations throughout; Basal carbonate member; end of section PVM 2a 1.1-1.8 Moderately sorted granule to pebble conglomerate with a medium- to coarse-grained sandy matrix; small cobble lenses throughout; ungraded; start of section PVM 2b; Basal carbonate member 1.8-2.3 Poorly sorted, pebble to boulder conglomerate, thins to 10 cm over a distance of 5 meters to the east; Basal carbonate member 78 2.3-2.8 Horizontlly stratified pebble conglomerate with a medium sand matrix; carbonate content is <10%; basal carbonate member; 2.6-6.2 Horizontally bedded pebble to cobble conglomerate with beds ranging from 0.8-1.1 meters thick; no internal stratification or imbrication; clasts are rounded-to subangular; clast composition is 90% locally derived volcanics and 10% from underlying carbonates; erosional basal contact; Quaternary inset gravel 6.2-7.4 Younger Quaternary Gravel Section PVM-3 Height in Description section (m) 0.0-0.9 Interbedded carbonate paper shale and 5 to 10 cm thick intedbeds of massive lime muds; upper marl; Sample 19PVM3-1 taken at 0.4m; Sample 19PMV3-2 taken at 0.6m; 0.9-1.0 Well sorted; fine-grained grainstone with minor siliciclastic component; pebble lag along base; weak horizontal stratification; 1.0-1.35 Well sorted, medium-grained grainstone; tabular cross-bedding along base is 15 cm thick and indicates currents directed towards 276°; upper 20 cm is horizontally stratified with abundant wave rippled tops; Sample 19PVM3-3 taken at 1.25m; 1.35-1.9 Rhythmically bedded, well sorted, fine-grained sandy grainstone; individual beds are 1-2 cm thick; bedding plane surface is highly bioturbated and shows burrow mottling; Sample 19PVM3-4 taken at 1.6m; Sample 190126-16 taken at 1.8m; Unit this to the west due to erosion and channelization from overlying unit; 1.9-2.6 Poorly sorted, pebble to cobble conglomerate with a coarse-grained grainstone matrix; unit fines upwards to a poorly sorted granule to pebble conglomerate; upper 15 cm is a pebble to cobble lag; coralline red algae fragments are abundant; unit fills a channel inset into underlying unit; Sample 190126-17 taken at 2.1m; 79 2.6-4.2 Interbedded bracciate red mudstone with sizable grainstone-filled desiccation cracks and root casts; rhizoliths and pedogenic features common; four interbeds of coarse grained pebbly grainstone with abundant shell fragments are each 10 cm thick; Sample 19PVM3-5 taken at 3.35m; Sample 19PVM3-6 taken at 3.55m; 4.2-5.0 Rhythmically bedded/laminated, well sorted, fine-grained sandy grainstone; Sample 19PVM3-7 taken at 4.4m; Sample 19PVM3-8 taken at 4.6m 5.0-5.6 Poorly sorted, coarse-grained, sandy, pebbly, fossiliferous grainstone; with thin (1-2 cm thick) planar bedding; 60% carbonate; fossils are dominantly barnacles and bivalves; 5.6-7.6 Quaternary Gravel Section PVM-4 Height in Description section (m) 0.0-0.9 Planar to wavy-flaser bedded calcisiltite with thin (1 mm) lime mud interbeds; unusual facies of the upper marl; upper surface has cracks and fissures; Sample 19PVM4-1 taken at 0.4 m; 0.9-1.02 Siliciclastic green clay rich carbonate paper shale; upper marl; Sample 19PVM4-2 taken at 0.95 m 1.02-1.2 Karst breccia with clasts ranging from1.5 cm to 15x25 cm; clasts are composed of underlying unit, large reworked charophytes; dissolution cracks common; matrix is a poorly sorted, fine- to coarse-grained grainstone; no siliciclastics; upper marl; Sample 19PVM4-3 taken at 1.1 m 80 1.2-2.45 Moderately sorted, coarse-grained grainstone with cobble to boulder lags; planar to long wavelength convex up bedding; heavily bioturbated; thalassinoides burrows, rhodoliths, and coralline red algae are abundant; individual beds average 10-15 cm; can trace beds laterally westward into overlying cross-bedded conglomerates; possibly distal bottomsets; upper bioclastic member; Sample 19PVM4-4 taken at 1.5 m; Sample 19PVM4-5 taken 1.75 m; Sample 19PVM4-6 taken at 2.35 m; Sample S190127-18 taken at 2.2 m 2.45-2.70 Calcareous matrix granule conglomerate that fines upward to coarse-grained sandy grainstone; Sample 19PVM4-7 taken at 2.6 m; 2.7-2.8 Poorly sorted, subrounded granule conglomerate with <30% carbonate in matrix; no internal structures; 2.8-3.8 Poorly sorted pebble to cobble conglomerate; clast supported; matrix is a very coarse grained sandy fossiliferous grainstone; foresets (1 m thick) dip to SE; Sample S190127-19 taken at 2.9 m Section PVM-5 Height in Description section (m) 0.0-0.25 Interbedded lime mud and calcisiltite with wavy to planar stratification; Basal carbonate member 0.25-0.75 Well sorted, very fine- to fine- grained sandy grainstone with 1-5 mm thick lime mud interbeds; grainstone beds are heavily bioturbated; grainstone bed thicknesses increase from 1-3 cm at the base to 10 cm at the upper contact; mud interbeds show desiccation cracks; abundance of mud decreases towards the top of the unit; 0.75-0.95 Massive, structureless, very fine-grained grainstone with minor siliciclastic component; heavily bioturbated; 0.95-1.0 Planar to wave ripple laminated, well sorted, medium-grained sandy grainstone with minor siliciclastic pebbles; 1.0-1.1 Very coarse-grained, barnacle rich grainstone with no internal structures 81 1.1-1.45 Well sorted, medium-grained sandy grainstone with wavy to planar bedding with minor bioturbation; 1.45-1.55 Massive calcisiltite 1.55-1.8 Well sorted, fine- to medium-grained sandy grainstone with low angle (18°) crossbedding dipping towards 137°; 1.8-1.95 Laterally discontinuous layer of well sorted; fine-grained sandy grainstone with cross-bedding indicating transport to 290°; 1.95-2.2 Well sorted, fine- to medium-grained sandy grainstone with cross-bedding dipping towards 130° 2.2-2.25 Massive calcisiltite interbed 2.25-2.7 Poorly sorted, granule-sized fossilferous grainstone with abundant barnacle and bivalve fragments; cross-bedding indicates transport towards 134°; cross-bed thickness is 0.5 m 2.7-2.8 Massive calcisiltite with minor siliciclastic pebbles 2.8-3.4 Poorly sorted, granule sized fossiliferous sandy grainstone; crossbedding indicates transport to the 128°; cross-bed thickness is 0.6 m 3.4-3.7 Moderately sorted, coarse-grained sandy grainstone; planar beds are 10-15 cm thick; 3.7-4.3 Moderately sorted, very coarse-grained fossiliferous grainstone beds (5-10 cm thick) interbedded with poorly sorted, subrounded to subangular pebble- cobble conglomerate; conglomerate matrix is <65% carbonate; 4.3-5.5 Quaternary Gravel 82 Section PVM-6 Height in Description section (m) 0.0-3.5 Moderately sorted, granule to pebble conglomerate with low angle to horizontal stratification; clast supported with a fine- to medium-grained sand matrix; elongate 2-3 m lenses of cobble conglomerate are common; subangular clasts; large cobbles have in-situ barnacles; Basal carbonate member 3.5-3.7 Poorly sorted, pebble to cobble conglomerate with travertine encrusted clasts; subrounded clasts; matrix is a very fine-grained grainstone; clast supported 3.7-3.9 Moderately to poorly sorted, granule to pebble conglomerate with low angle cross-stratification; Carbonate in matrix is <10% 3.9-4.1 Poorly sorted, cobble conglomerate with medium sand matrix; clast supported; carbonate in matrix is <10%; subangular clasts; ungraded 4.1-4.5 Poorly sorted, granule to pebble conglomerate with sporadic, discontinuous cobble lags throughout; clasts are subangular; horizontally to low angle stratified 4.5-4.7 Massive calcisiltite bed 4.7-7.4 Interbedded calcisiltite and very fine-grained grainstone; individual beds range from 2-8cm thick; bedding surfaces are planar or wavy; Pebble- cobble conglomerate is inset into a channel from 6.7-7.0m; upper 40 cm contains wave ripple beds; 7.4-7.8 Poorly sorted, cobble conglomerate; angular clasts; ungraded; carbonate in matrix is >60% 7.8-8.2 Well sorted, coarse-grained grainstone with SE directed tabular cross- bedding (not a full bed-set); 8.2-9.2 Quaternary Gravel Section PVM-7 83 Height in Description section (m) 0.0-1.3 Moderately sorted, granule to pebble conglomerate with low angle to horizontal crossbedding; discontinuous cobble lags throughout; coarsens up to a cobble conglomerate in upper 25 cm; basal carbonate member 1.3-1.8 Channelized, well sorted, granule conglomerate with bi-directional crossbedding (point bars); subrounded clasts; matrix is <70% carbonate; 1.8-2.4 Moderately sorted, weakly stratified, granule conglomerate with minor pebble component; no lags visible; carbonate is <30% 2.4-2.5 Structureless, well sorted, fine-grained sandy grainstone 2.5-2.9 Poorly sorted, ungraded, cobble conglomerate; angular to subangular clasts; carbonate in matrix is <50% 2.9-3.1 Horizontally stratified, interbedded massive calcisiltate and very fine- grained sandy grainstone; individual beds range from 1-3 cm thick 3.1-4.9 Interbedded calcisiltite and very fine- to fine-grained grainstone; wavy to planar bedding throughout; charophyte beds occur discontinuously along bedding planes 4.9-5.5 Moderately sorted, lenticular to flaser bedded calcisiltite, very fine- to fine grained sandy grainstone, and lime mud; mud content decreases towards top of unit; 5.5-5.7 Moderately sorted, granule-sized fossiliferous grainstone with 20 cm thick cross-beds. 5.7-6.1 Poorly sorted, inversely graded pebble-cobble conglomerate; carbonate in matrix is ~50% Section PVM-8 Height in Description section (m) 84 0.0-0.35 Moderately sorted, angular to subangular, pebble to cobble conglomerate with weak horizontal stratification; <5% carbonate in matrix; Basal carbonate member 0.35-0.4 Poorly sorted, pebbly, fine-grained sandy grainstone with wavy bedding; 0.4-0.5 Moderately sorted, pebbly, coarse-grained sandy grainstone with no internal structures; 0.5-1.55 Poorly sorted, coarse-grained pebbly sandstone with low angle cross- stratification to horizontal bedding; Lenticular pebble-cobble conglomerate patches with angular clasts are abundant; 1.55-1.85 Massive, very fine- to fine-grained sandy grainstone with heavy bioturbation; thalassinoides burrows, barnacles, mollusks and ostracizes common; 1.85-2.8 Planar and wavy bedded calcisiltite and very fine- to fine-grained grainstone; individual beds range from 1-5 cm thick; 2.8-3.0 Horizontally stratified lime mud bed; individual beds are 1-2 mm thick; 3.0-4.3 Wavy-flaser-lenticular bedded very fine- to fine-grained calcarenite, lime mud, and calcisiltite; individual beds are very well sorted; minor planar bedding; 4.3-4.6 Poorly sorted, granule to pebble conglomerate with weakly developed horizontal to low angle stratification; subangular to surrounded clasts; carbonate in matrix is <20%; 4.6-4.7 Poorly sorted, granule-sized fossiliferous sandy grainstone with abundant barnacle and mollusk fragments; no internal structures; 4.7-5.0 Poorly sorted, inversely graded, pebble to cobble conglomerate with fine- to coarse-grained matrix; matrix is <60% carbonate; 5.0-9.5 Quaternary Gravel Section PVM-9 85 Height in Description section (m) 0.0-0.3 Poorly sorted, pebble conglomerate with sandy matrix; angular to subangular clasts; no internal structures; Basal carbonate member 0.3-0.55 Well sorted, very fine-grained grainstone with no internal structures; bivalve shells (<4 mm across) throughout; 0.55-0.65 Thinly bedded, wave ripple laminated, calcisiltite and very fine-grained sandy grainstone; 0.65-1.05 Very fine-grained grainstone with planar to wavy bedding; thin mud interbeds (5 mm thick) show dessication cracks on exposed bedding surfaces; 1.05-1.1 Massive lime mud 1.1-1.8 Very fine- to fine-grained sandy grainstone with planar and wavy bedding; lime mud interbeds are 2 mm thick; mud bedding plane surfaces show grainstone filled desiccation cracks; 1.8-2.4 Interbedded calcisiltite and very fine-grained grainstone with abundant wavy bedding; wavelengths of wavy bedding is 0.4 m; lime mud observed in discontinuous mud drapes on wavy bedforms; lime mud beds are <1 cm thick; grainstone and calcisiltite beds range from 2-5 cm thick; 2.4-2.65 Heavily bioturbated, structureless, very fine- to fine-grained sandy grainstone; rare ripple laminations preserved; 2.65-2.75 Poorly sorted, pebbly, granule conglomerate with abundant shell fragments; matrix is a coarse-grained grainstone; no internal structures or imbrication; 2.75-2.85 Structureless, poorly sorted, pebbly, medium-grained sandy grainstone 2.85-2.95 Poorly sorted, granule-sized, fossiliferous sandy grainstone; no internal structures 2.95-3.05 Structureless, poorly sorted, pebbly, medium-grained sandy grainstone 86 3.05-3.45 Structureless, poorly sorted, pebble conglomerate with a fossilferous grainstone matrix; 15 cm thick lenses of coarse-grained grainstone throighout; conglomerate is weakly stratified; 3.45-3.6 Poorly sorted, medium- to coarse-grained pebbly sandy grainstone with planar laminations throughout 3.6-4.3 Poorly sorted, unstratified, cobble to boulder conglomerate; matrix is a poorly sorted, coarse-grained to granule sized fossiliferous grainstone; no internal structures; clasts are angular to subangular; 4.3-4.5 Poorly sorted, medium-grained pebbly grainstone with weak internal stratification 4.5-5.1 Moderately sorted, granule-sized fossiliferous grainstone with abundant 10 cm thick granule to pebble conglomerate lenses; weakly stratified 5.1-5.9 Moderately sorted, coarse- to very-coarse grained fossiliferous sandy grainstone; low angle cross-bedding throughout; individual foresets are 1-5 cm thick; abundant barnacles, mollusks and rhodoliths; 5.9-7.7 Quaternary Gravel Section PVM-10 Height in Description section (m) 0.0-0.7 Interbedded calcisiltite and very fine-grained grainstone; beds are 1-3 cm thick and show both planar laminations and wave rippled surfaces; 0.7-1.9 Wavy-Flaser bedded very fine- to fine-grained grainstone with thin (1-2 mm thick) lime mud beds; interbedded with poorly sorted, very coarse-grained to granule-sized fossiliferous grainstone with tabular cross-beds; cross-beds are 10 cm thick; finer beds range from 5-10 cm thick; 1.9-2.1 Well sorted, interbedded calcisiltite and very fine-grained sandy grainstone with wavy-flaser bedding; 2.1-2.2 Very fine-grained grainstone and calcisiltite with abundant reed casts in life position; 87 2.2-2.3 Massive lime mud with minor reed casts; 2.3-2.6 Moderately sorted; coarse- to very coarse-grained grainstone and fossiliferous grainstone with low angle (10°) crossbedding; unit pinches out two meters to the east; 2.6-2.95 Horizontally bedded, medium- to coarse-grained grains tine with abundant reed casts at the base; individual beds range from 3-5 cm; 2.95-3.1 Poorly sorted, pebble conglomerate with subangular to surrounded clasts; no internal structures; matrix is a fine-grained sand with 30-40% carbonate 3.1-3.2 Wavy-flaser bedded very fine-grained grainstone and lime mud; 3.2-3.5 Heavily bioturbated, structureless, calcisiltite and very fine-grained grainstone; 3.5-3.8 Heavily bioturbated, structureless, fine-grained sandy grainstone 3.8-4.0 Wavy-flaser bedded, calcisiltite and very fine-grained sandy grainstone; 4.0-4.15 Weakly stratified, bioturbated, very fine- to fine-grained sandy grainstone; 4.15-4.45 Rhodolith bearing, barnacle rich, fine- to medium-grained grainstone with weak planar laminations; 4.45-4.6 Weakly stratified, ripple laminated fine-grained sandy grainstone; 4.6-4.9 Rhodolith bearing, fine-grained grainstone; heavily bioturbated; 4.9-5.3 Granule-sized, fossiliferous grainstone with abundant barnacles and bivalves; tabular cross-beds indicating SE transport (138°) are 40 cm thick 5.3-5.8 Tabular cross-bedded, moderately sorted, coarse to very coarse-grained fossiliferous sandy grainstone with abundant shell fragments; cross-bed sets are 0.5 m thick and indicate transport to the SE (143°) 5.8-7.8 Tabular cross-bedded, coarse- to very coarse-grained fossiliferous grainstone; cross-bed thickness unreliable due to heavy cover and lack of full sets; 88 7.8-8.8 1 meter thick tabular cross-bedded, medium- to coarse-grained sandy grainstone; upper bioclastic member; small coralline red algae fragments sparsely distributed throughout; 9.8 Quaternary Gravel Section PVM-11 Height in Description section (m) 0.0-2.2 Thinly bedded red mudstone; weakly developed soil horizons in upper 10 cm; horizontal and vertical zones of bright orange discoloration along bedding planes; white, vertical rhizocretions throughout; 2.2-2.25 Well sorted, fine-grained sandy grainstone; structureless 2.25-4.0 Thinly bedded to massive red mudstone; massive beds are 8 cm thick; fewer orange discolorations than lower unit; 4.0-4.35 Hortizontally laminated, well sorted, very fine- to fine-grained Colorado River derived sandstone; 4.35-4.45 Thinly bedded siltstone 4.45-6.45 Interbedded very fine-grained sandstone and siltstone with abundant planar laminations; orange discoloration common throughout; individual beds range from 1-4 cm thick; 6.45-8.8 Thinly bedded red mudstone with minor, discontinuous interbeds of siltstone; common orange discoloration along bedding plane surfaces; 89 8.8-9.4 Interbedded, poorly cemented siltstone and very fine-grained sandstone; minor granules throughout; individual beds are 3 cm thick; 9.4-12.2 Quaternary Gravel Section PVM-12 Height in Description section (m) 0.0-3.5 Well sorted, well rounded, medium-grained Colorado River sandstone with amalgamated, multi-storey trough crossbedding; trough axes oriented 176° 3.5-9.2 Well sorted, well rounded, fine- to medium grained Colorado River sandstone with amalgamated, multi story trough-cross-bedding; trough axes oriented 170° 9.2-9.6 Well sorted, well rounded, fine-grained Colorado River sandstone with planar laminations throughout; 9.6-11.5 Poorly sorted, medium- to coarse-grained pebbly sandy grainstone with long wavelength (40-50 cm) convex-up bedforms; pinch and swell geometry in pebble lenses throughout; pebbles concentrated in convex up lenses; pebbles are subangular to subrounded; upper bioclastic member; 11.5-13.0 Poorly sorted, pebble to cobble conglomerate with very weak stratification; subangular clasts; matrix is a fine-to medium grained sand with <50% carbonate; 13.0-16.3 Interbedded calcareous matrix, pebble to cobble conglomerate and poorly sorted, medium- to coarse-grained pebbly sandstone with minor carbonate; highly stratified; conglomerate and pebbly sandstone beds range from 40-50 cm thick; upper 50 cm has wave rippled surfaces in the pebbly sandstone and long wavelength (1 m) convex up bedrooms throughout; 16.3-17.8 Quaternary Gravel Section PVM-13 90 Height in Description section (m) 0.0-2.6 Tertiary volcanics; crystal tuff; 2.6-3.0 Angular cobble to boulder volcanic clasts; surrounded by tuffaceous matrix; lahar? 3.0-3.2 Poorly sorted, granule to cobble calcareous matrix conglomerate; inversely graded; basal carbonate member; 3.2-3.4 Moderately sorted, granule to pebble conglomerate; horizontally stratified; rounded to subrounded clasts; 3.4-3.7 Massive, well cemented, lime mud 3.7-5.2 Horizontally stratified, interbedded calcisiltite and very fine- to fine-grained grainstone; thin lime mud interbeds throughout; wavy bedding throughout; thalassinoides burrows observed on basal surfaces; ripples preserved on bedding plane surfaces; 5.2-6.15 Massive to highly laminated lime mud; well stratified; upper marl 6.15-6.8 Moderately sorted, granule-sized fossiliferous sandy grainstone; 0.5 m thick trough crossbedding with axes oriented 85°; bivalve and barnacle fragments throughout; upper bioclastic member 6.8-9.1 Horizontally stratified, very fine- to fine grained sandy grainstone with planar, medium-grained sandy grainstone interbeds (20 cm thick) throughout; Individual beds are 50 cm thick and are structureless 9.1-9.7 Moderately sorted, fine-grained pebbly sandy grainstone with abundant coralline red algae fragments; structureless 9.7-10.2 Planar bedded, granule-sized fossiliferous sandy grindstone with abundant bivalves and barnacles; 10.2-10.4 Wavy-flaser bedded, fine-grained sandy grainstone; thin (2 cm thick) interbed of granule-sized fossiliferous grainstone 10.4-10.7 Very coarse-grained fossiliferous sandy grainstone with minor cobbles; coralline red algae throughout; no pebbles or cobbles in upper 10 cm; 91 10.7-10.8 Wavy bedded, fine-grained sandy grainstone 10.8-11.7 Inversely graded; poorly sorted, pebbly granule-sized fossiliferous sandy grainstone that coarsens upwards into a calcareous matrix cobble conglomerate; abundant coralline red algae fragments 11.7-12.1 Wavy bedded, fine- to medium-grained sandy grainstone with abundant barnacles; wave ripple lamentations preserved throughout; minor pebble component 12.1-12.3 Coarse- to very-coarse grained pebbly sandy fossiliferous grainstone; long wavelength (3 m) convex up bedding 12.3-13.1 Horizontally to low angle stratified, well sorted, coarse-grained pebbly sandy grainstone; Long wavelength (3m) pinch and swell bedding sporadic throughout; 13.1-13.2 Wavy bedded and wave ripple laminated; fine-grained sandy grainstone; 13.2-13.55 Weakly stratified, coarse- to very-coarse grained sandy grainstone with abundant barnacle, bivalve, and coralline red algae fossils 13.55-13.7 Poorly sorted cobble conglomerate with subrounded clasts; matrix is a fine- to medium-grained grainstone; 13.7-13.95 Wavy bedded and wave ripple laminated; fine-grained sandy grainstone; 13.95- Coarse- to very coarse-grained pebbly fossiliferous sandy grainstone; lower 14.35 20 cm is structureless with abundant shell fragments; upper 20 cm are weakly stratified 14.35-14.4 Structureless, fine-grained sandy grainstone 14.4-15.35 Poorly sorted, coarse- to very coarse-grained pebbly sandy fossiliferous grainstone; lower 60 cm are structureless; upper 35 cm are horizontally stratified 15.35- Structureless, fine-grained sandy grainstone; discontinuous cobble lag 15.45 along base; wave rippled top; 15.45-16.1 Planar bedded, moderately sorted, very coarse-grained, pebbly sandy grainstone; individual beds range from 1-5 cm thick; 92 16.1-21.1 Cover/Quaternary Gravel Section PP-1 Height in Description section (m) 0.0-0.2 Interbedded calcisiltite and very-fine-grained grainstone with abundant thalassinoides burrows; thinly bedded (0.5-1 cm thick beds) 0.2-1.6 Well sorted, medium- to coarse-grained sandy grainstone; planar tabular cross-bedding indication southward transport; cross-bed thickness is 1.4m thick; granule-sized fossiliferous grainstone concentrated on sigmoidal reactivation surfaces along foresets; climbing ripples common near upper portions of foresets 1.6-1.95 Well sorted, fine-grained grainstone with low angle stratification; heavily bioturbated; bottom sets 1.95-3.65 Well sorted, medium- to coarse- grained sandy grainstone; granule-sized fossiliferous grainstone concentrated along sigmoidal reactivation surfaces; cross-bedding is 1.7 meters thick and indicates transport towards 178°; 3.65-4.3 Well sorted, medium- to coarse- grained sandy grainstone; granule-sized fossiliferous grainstone concentrated along sigmoidal reactivation surfaces; cross-bedding is 0.65 meters thick and indicates transport towards 181°; 4.3-4.7 Well sorted, medium- to coarse- grained sandy grainstone; granule-sized fossiliferous grainstone concentrated along sigmoidal reactivation surfaces; cross-bedding is 0.4 meters thick and indicates transport towards 174°; 4.7-4.85 Well sorted, medium- to coarse- grained sandy grainstone; granule-sized fossiliferous grainstone concentrated along sigmoidal reactivation surfaces; cross-bedding is 0.15 meters thick and indicates transport towards 184°; 93 Section PP-2 94 Thickness (m) Section SR-1 Height in Description section (m) 0.0-0.65 Poorly sorted, medium- to very coarse-grained fossiliferous sandy grainstone; ~30% siliciclastics; south east directed 65 cm thick cross- bedding; 0.65-0.8 Very coarse-grained fossiliferous sandy grainstone with southeast directed 15 cm thick cross-bedding 0.8-1.0 Well sorted, fine- to medium-grained sandy grainstone with planar and wave rippled bedding; 1.0-1.7 Moderately to poorly sorted, medium- to coarse-grained pebbly grainstone with 35 cm thick, SE directed crossbedding (127°) 1.7-1.95 Festoon cross-bedded pebbly fossiliferous sandy grainstone; 50% siliciclastics; axes of cross-beds trend 178°; 1.95-2.2 Granule-sized fossiliferous sandy grainstone with abundant bivalve and barnacle fragments; 25 cm thick cross-beds indicate transport towards 136° 2.2-2.95 Well sorted, fine-grained grainstone with planar bedding; individual beds are heavily burrow mottled and contain thalassinoides burrows; 2.95-3.15 Fine- to medium-grained grainstone with abundant shell fragments; low angle to horizontal stratification. Section SR-2 Height in Description section (m) 0.0-0.3 Interbedded calcisiltite and very fine-grained sandy grainstone; planar to wavy bedding throughout; individual beds are 1-3 cm thick 0.3-1.3 Moderately to well sorted, coarse- to very-coarse grained pebbly grainstone with tabular cross-bedding; cross-beds range from 30-35 cm thick and foresets dip towards 88°; 95 1.3-2.0 Moderately sorted granule-sized sandy fossiliferous grainstone with minor pebble component; 0.7 m thick tabular cross-beds have foresets that dip 25° towards 90°; 2.0-2.55 Well sorted, medium-grained fossiliferous sandy grainstone; tabular cross- bed sets range from 10-25 cm thick and indicate transport towards 93°; 2.55-2.85 Interbedded granule-sized fossiliferous sandy grainstone and fine-grained wave rippled grainstone; individual beds are 10 cm thick; 2.85-3.65 Medium- to very coarse-grained sandy grainstone and granule sized fossiliferous pebbly grainstone; East directed tabular cross-beds range from 15-30 cm thick; 3.65-4.4 Well sorted, very fine- to fine grained grainstone with a single 10 cm thick siliclastic and carbonate mud interbed; grainstone is burrow mottled and mildly bioturbated; 4.4-4.6 Well sorted, fine- to medium-grained sandy fossiliferous grainstone with low angle, east directed cross-beds (20 cm thick) 4.6-4.9 Well sorted, very coarse-grained to granule-sized fossiliferous grainstone with <10% siliciclastics; tabular cross-beds (10 cm thick) are oriented 92° 4.9-5.15 Well sorted, granule-sized fossiliferous sandy grainstone with abundant bivalve and barnacle shell fragments; low angle cross-bedding (25 cm thick) indicates eastward transport Section SR-3 Height in Description section (m) 0.0-0.35 Medium- to coarse-grained, moderately sorted, sandy grainstone; 35 cm thick cross-bed indicates transport towards 96° 0.35-0.45 Well sorted, fine- to medium grained sandy grainstone; planar stratification minor shell fragments 96 0.45-0.75 Poorly sorted, very coarse-grained to granule-sized pebbly fossiliferous grainstone; cross-bed sets (20 cm thick) indicate transport towards 85° 0.75-1.6 Well sorted, interbedded calcisiltite and very fine- to fine-grained grainstone; wavy and planar bedding; wave ripple laminations preserved throughout 1.6-1.8 Poorly sorted, granule-sized fossiliferous grainstone; unit grades laterally eastward into underlying unit; low angle stratification 1.8-2.15 Well sorted, medium-grained sandy grainstone; 35 cm thick cross-bed sets indicate transport towards 87° 2.15-2.85 Poorly sorted, coarse-grained to granule-sized fossiliferous sandy grainstone; sigmoidal cross-bedding is 40 cm thick and indicates transport towards 95°; single 10 cm thick, laterally discontinuous cross-bed indicates transport towards 277° 2.85-3.0 Poorly sorted, granule-sized fossiliferous grainstone; 15 cm thick cross-bed set indicates transport towards 268°; Section SR-4 Height in Description section (m) 0.0-0.4 Moderately to well sorted, coarse- to very coarse-grained fossiliferous grainstone with weakly preserved east directed sigmoidal crossbedding 0.4-0.55 Very well cemented fine-grained, well sorted sandy grainstone; structureless 0.55-0.8 Well sorted, fine-grained grainstone with poorly preserved wave ripple laminations; burrow mottling throughout 0.8-0.9 Very coarse-grained fossiliferous grainstone with 30 cm wavelength rippled surfaces; barnacle and bivalve fragments abundant; 0.9-0.95 Structureless, fine-grained sandy grainstone 97 0.95-1.95 Poorly sorted, coarse-grained to granule-sized fossiliferous grainstone; nearly pure carbonate; abundant barnacle and mollusk fragments; sigmoidal cross-beds 50 cm thick indicate transport towards 94°; pebbles appear in upper 20 cm 1.95-2.15 Structureless, fine-grained sandy grainstone 2.15-2.4 Interbedded coarse-grained grainstone and fine-grained grainstone; individual beds are 5 cm thick; base of uppermost coarse-grained grainstone bed has cobble lag 2.4-2.7 Well sorted, very fine-grained sandy grainstone; heavily bioturbated in basal 20 cm; upper 10 cm shows wavy bedding and lime mud drapes 2.7-3.05 Medium-grained sandy grainstone with minor granules; coarsens upward into pebbly granule-sized fossiliferous sandy grainstone; sigmoidal cross- bed 35 cm thick indicates transport towards 93° 3.05-3.75 Coarse- to very coarse grained grainstone and granule-sized fossiliferous sandy grainstone; minor pebbles throughout; sigmoidal cross-beds ranging from 20-30 cm thick are eastward directed; highly weathered 3.75-4.05 Structureless calcisiltite; heavily bioturbated 4.05-4.4 Heavily bioturbated, structureless, very fine-grained sandy grainstone; single 10 cm thick clam bed interbedded from 4.1-4.2 m; 4.4-4.75 Poorly sorted, very coarse-grained to granule-sized fossiliferous sandy grainstone with low angle stratification dipping 10° to the east; 4.75-5.65 Moderately sorted, granule-sized fossiliferous sandy grainstone with abundant barnacle and mollusk fragments; east directed cross-bedding is amalgamated Continued on following page 98 Section SR-5 99 APPENDIX C PETROGLYPH PARK PALEOCURRENT DATA Latitude Longitude Dip Dip Simple Dune Thickness Surface Direction (cm) Order 33.41242 -114.69668 29 196 15 1 33.41242 -114.69668 19 6 12 1 33.41242 -114.69668 22 355 15 1 33.41242 -114.69668 20 2 10 1 33.41242 -114.69668 27 202 x 1 33.41242 -114.69668 26 198 80 1 33.41242 -114.69668 27 186 123 1 33.41242 -114.69668 29 183 180 1 33.41242 -114.69668 23 188 55 1 33.41242 -114.69668 27 179 40 1 33.41242 -114.69668 29 181 1.2 1 33.41242 -114.69668 23 174 40 1 33.41242 -114.69668 27 184 50 1 33.41242 -114.69668 32 178 150 1 33.41242 -114.69668 22 177 60 1 33.41242 -114.69668 34 175 100 1 33.33576 -114.72308 35 141 x 1 33.33572 -114.72304 34 161 x 1 33.33572 -114.72305 36 146 x 1 33.33663 -114.72230 29 175 x 1 33.33706 -114.72189 15 357 x 1 33.33702 -114.72183 11 148 x 1 33.33699 -114.72188 10 9 x 1 33.33703 -114.72188 14 211 x 1 100 Latitude Longitude Dip Dip Simple Dune Thickness Surface Direction (cm) Order 33.33654 -114.72185 9 322 x 1 33.33656 -114.72189 22 162 x 1 33.33658 -114.72146 23 209 x 1 33.33658 -114.72146 25 183 x 1 33.33659 -114.72136 15 356 x 1 33.33657 -114.72151 29 183 x 1 33.33653 -114.72144 29 179 x 1 33.33658 -114.72146 15 352 x 1 33.33657 -114.72143 22 334 x 1 33.33646 -114.72145 33 171 x 1 33.33648 -114.72149 37 171 x 1 33.33640 -114.72140 43 175 x 1 33.33637 -114.72154 23 179 x 1 33.33651 -114.72144 23 180 x 1 33.33650 -114.72144 35 172 x 1 33.33644 -114.72144 30 170 x 1 33.33653 -114.72150 26 172 x 1 33.33651 -114.72153 25 152 x 1 33.35907 -114.72657 38 335 x 1 33.35908 -114.72657 31 137 15 1 33.35906 -114.72655 23 134 12 1 33.35908 -114.72655 18 263 10 1 33.35899 -114.72662 29 264 x 1 33.33647 -114.72146 28 182 180 1 33.33673 -114.72134 21 181 100 1 33.33686 -114.72097 33 191 110 1 33.33677 -114.72124 20 175 x 1 33.33676 -114.72119 31 161 x 1 33.33685 -114.72116 26 161 x 1 101 Latitude Longitude Dip Dip Simple Dune Thickness Surface Direction (cm) Order 33.33685 -114.72116 11 330 x 1 33.33693 -114.72134 16 164 x 1 33.33486 -114.72310 34 150 x 1 33.33531 -114.72350 28 144 x 1 33.33524 -114.72346 23 142 x 1 33.33516 -114.72324 31 149 x 1 33.35906 -114.72647 24 86 15 1 33.35905 -114.72645 13 90 5 1 33.35909 -114.72645 18 190 8 1 33.35918 -114.72620 20 185 4 1 33.35925 -114.72623 17 196 4 1 33.35928 -114.72629 19 266 3 1 33.35908 -114.72614 15 267 5 1 33.35914 -114.72629 18 265 5 1 33.35919 -114.72622 17 175 40 1 33.35922 -114.72624 15 100 35 1 33.35928 -114.72621 18 96 38 1 33.35915 -114.72646 15 96 15 1 33.35915 -114.72646 15 98 32 1 33.35914 -114.72657 21 86 40 1 33.35909 -114.72649 25 75 35 1 33.35909 -114.72649 31 72 25 1 33.33632 -114.72144 25 179 x 1 33.33594 -114.72264 29 149 x 1 33.33594 -114.72266 30 157 x 1 33.33591 -114.72271 31 134 x 1 33.33594 -114.72280 31 143 x 1 33.33594 -114.72280 32 152 x 1 33.33591 -114.72276 24 155 x 1 102 Latitude Longitude Dip Dip Simple Dune Thickness Surface Direction (cm) Order 33.33638 -114.72075 24 284 x 1 33.33637 -114.72071 27 286 x 1 33.33641 -114.72142 39 160 x 1 33.33700 -114.72121 15 232 x 1 33.33704 -114.72122 19 226 x 1 33.33704 -114.72127 19 230 x 1 33.33548 -114.72314 16 168 x 1 33.33717 -114.72366 21 81 x 1 33.33706 -114.72366 28 83 x 1 33.33699 -114.72362 28 261 x 1 33.33722 -114.72368 29 281 x 1 33.33590 -114.72245 24 184 x 1 33.41242 -114.69668 14 190 N/A 2 33.41242 -114.69668 21 183 N/A 2 33.41242 -114.69668 22 185 N/A 2 33.41242 -114.69668 12 185 N/A 2 33.41242 -114.69668 13 190 N/A 2 33.41242 -114.69668 17 177 N/A 2 33.41242 -114.69668 11 192 N/A 2 33.41242 -114.69668 18 189 N/A 2 33.41242 -114.69668 18 181 N/A 2 33.41242 -114.69668 17 179 N/A 2 33.41242 -114.69668 14 186 N/A 2 33.41242 -114.69668 23 181 N/A 2 33.41242 -114.69668 13 175 N/A 2 33.41242 -114.69668 24 179 N/A 2 33.33580 -114.72307 26 133 N/A 2 33.33579 -114.72304 28 154 N/A 2 33.33658 -114.72146 9 210 N/A 2 103 Latitude Longitude Dip Dip Simple Dune Thickness Surface Direction (cm) Order 33.33658 -114.72146 10 191 N/A 2 33.33659 -114.72153 29 186 N/A 2 33.33655 -114.72149 16 191 N/A 2 33.33650 -114.72139 27 170 N/A 2 33.33643 -114.72138 23 180 N/A 2 33.33640 -114.72139 20 180 N/A 2 33.33641 -114.72142 11 170 N/A 2 33.33648 -114.72156 21 167 N/A 2 33.33651 -114.72143 27 170 N/A 2 33.33639 -114.72152 37 164 N/A 2 33.33650 -114.72145 29 177 N/A 2 33.33651 -114.72151 23 153 N/A 2 33.33651 -114.72147 19 175 N/A 2 33.33681 -114.72117 13 181 N/A 2 33.33675 -114.72131 14 179 N/A 2 33.33679 -114.72120 12 193 N/A 2 33.33678 -114.72123 9 185 N/A 2 33.33684 -114.72121 22 160 N/A 2 33.33705 -114.72130 9 157 N/A 2 33.33483 -114.72313 20 123 N/A 2 33.33517 -114.72322 23 140 N/A 2 33.35909 -114.72654 19 77 N/A 2 33.35910 -114.72651 6 86 N/A 2 33.35913 -114.72652 18 99 N/A 2 33.35912 -114.72649 19 81 N/A 2 33.35913 -114.72655 19 77 N/A 2 33.35914 -114.72655 18 77 N/A 2 33.35915 -114.72652 12 107 N/A 2 33.33593 -114.72264 29 168 N/A 2 104 Latitude Longitude Dip Dip Simple Dune Thickness Surface Direction (cm) Order 33.33596 -114.72266 30 152 N/A 2 33.33591 -114.72279 25 157 N/A 2 33.33596 -114.72279 24 143 N/A 2 33.33594 -114.72278 24 146 N/A 2 33.33589 -114.72281 16 140 N/A 2 33.33637 -114.72073 13 263 N/A 2 105 APPENDIX D STALLARD AREA PALEOCURRENT DATA Latitude Longitude Dip Dip Simple Dune Thickness Surface Direction (cm) Order 33.35479 -114.72755 17 230 4 1 33.35481 -114.72741 12 262 10 1 33.35910 -114.72616 5 253 5 1 33.35479 -114.72755 20 85 25 1 33.35917 -114.72617 7 262 6 1 33.35485 -114.72742 18 96 20 1 33.35479 -114.72755 10 244 11 1 33.35487 -114.72745 10 273 15 1 33.35919 -114.72612 2 264 16 1 33.35479 -114.72755 21 96 50 1 33.35479 -114.72755 23 93 35 1 33.35299 -114.72734 20 100 120 1 33.35918 -114.72616 16 238 15 1 33.35482 -114.72744 25 97 25 1 33.35478 -114.72705 23 110 23 1 33.35479 -114.72755 35 349 80 1 33.35479 -114.72755 23 93 50 1 33.35479 -114.72755 6 265 10 1 33.35299 -114.72734 20 82 45 1 33.35918 -114.72618 24 80 22 1 33.35479 -114.72745 22 263 25 1 33.35911 -114.72649 23 209 15 1 33.35469 -114.72709 24 104 20 1 33.35479 -114.72755 35 100 40 1 33.35479 -114.72755 15 98 30 1 106 Latitude Longitude Dip Dip Simple Dune Thickness Surface Direction (cm) Order 33.35479 -114.72755 15 259 15 1 33.35479 -114.72755 16 263 5 1 33.35299 -114.72734 24 103 40 1 33.35910 -114.72651 26 81 25 1 33.35908 -114.72642 21 181 5 1 33.35340 -114.72743 20 99 30 1 33.35915 -114.72621 7 179 8 1 33.35485 -114.72759 27 101 30 1 33.35466 -114.72705 16 106 30 1 33.35479 -114.72755 21 86 30 1 33.35479 -114.72755 14 265 12 1 33.35479 -114.72755 19 100 30 1 33.35299 -114.72734 21 102 110 1 33.35299 -114.72734 30 109 20 1 33.35339 -114.72747 13 277 30 1 33.35900 -114.72648 6 261 5 1 33.35913 -114.72646 24 80 20 1 33.35913 -114.72616 17 217 10 1 33.35484 -114.72753 33 96 130 1 33.35461 -114.72717 20 105 40 1 33.35479 -114.72755 26 96 25 1 33.35479 -114.72755 21 93 50 1 33.35479 -114.72755 17 258 10 1 33.35299 -114.72734 19 100 31 1 33.35299 -114.72734 20 101 25 1 33.35920 -114.72650 23 71 30 1 33.35905 -114.72640 23 91 45 1 33.35911 -114.72633 25 88 60 1 33.35491 -114.72754 30 96 130 1 107 Latitude Longitude Dip Dip Simple Dune Thickness Surface Direction (cm) Order 33.35475 -114.72705 22 100 30 1 33.35923 -114.72623 25 80 50 1 33.35921 -114.72625 24 79 70 1 33.35908 -114.72629 26 79 65 1 33.35916 -114.72615 23 77 40 1 33.35482 -114.72738 26 104 15 1 33.35479 -114.72755 36 87 70 1 33.35479 -114.72755 21 89 15 1 33.35299 -114.72734 18 94 30 1 33.35299 -114.72734 24 91 20 1 33.35335 -114.72750 21 87 35 1 33.35872 -114.72669 26 101 40 1 33.35912 -114.72633 32 95 70 1 33.35479 -114.72755 25 82 60 1 33.35898 -114.72646 32 82 20 1 33.35892 -114.72644 25 93 35 1 33.35486 -114.72762 38 99 150 1 33.35474 -114.72721 23 93 120 1 33.35329 -114.72745 7 264 3 1 33.35479 -114.72755 6 97 N/A 2 33.35914 -114.72612 9 95 N/A 2 33.35482 -114.72746 9 101 N/A 2 33.35479 -114.72755 12 87 N/A 2 33.35915 -114.72622 12 92 N/A 2 33.35487 -114.72747 3 90 N/A 2 33.35479 -114.72755 8 87 N/A 2 33.35918 -114.72615 10 83 N/A 2 33.35475 -114.72739 11 87 N/A 2 33.35479 -114.72755 9 85 N/A 2 108 Latitude Longitude Dip Dip Simple Dune Thickness Surface Direction (cm) Order 33.35479 -114.72755 10 91 N/A 2 33.35299 -114.72734 7 89 N/A 2 33.35921 -114.72623 16 81 N/A 2 33.35481 -114.72744 16 99 N/A 2 33.35473 -114.72707 8 100 N/A 2 33.35479 -114.72755 8 98 N/A 2 33.35479 -114.72755 9 82 N/A 2 33.35479 -114.72755 7 97 N/A 2 33.35299 -114.72734 8 92 N/A 2 33.35908 -114.72642 13 94 N/A 2 33.35918 -114.72623 15 85 N/A 2 33.35487 -114.72752 11 95 N/A 2 33.35469 -114.72709 8 94 N/A 2 33.35479 -114.72755 8 94 N/A 2 33.35479 -114.72755 8 91 N/A 2 33.35479 -114.72755 7 85 N/A 2 33.35479 -114.72755 9 86 N/A 2 33.35299 -114.72734 9 97 N/A 2 33.35341 -114.72749 7 100 N/A 2 33.35906 -114.72646 9 88 N/A 2 33.35905 -114.72640 13 81 N/A 2 33.35917 -114.72615 14 88 N/A 2 33.35471 -114.72712 8 106 N/A 2 33.35479 -114.72755 8 89 N/A 2 33.35479 -114.72755 8 89 N/A 2 33.35479 -114.72755 10 98 N/A 2 33.35299 -114.72734 5 102 N/A 2 33.35299 -114.72734 8 101 N/A 2 33.35908 -114.72644 11 87 N/A 2 109 Latitude Longitude Dip Dip Simple Dune Thickness Surface Direction (cm) Order 33.35920 -114.72631 16 86 N/A 2 33.35486 -114.72751 20 97 N/A 2 33.35473 -114.72705 10 94 N/A 2 33.35479 -114.72755 7 83 N/A 2 33.35479 -114.72755 10 87 N/A 2 33.35479 -114.72755 10 92 N/A 2 33.35299 -114.72734 7 93 N/A 2 33.35299 -114.72734 7 100 N/A 2 33.35919 -114.72653 18 77 N/A 2 33.35904 -114.72633 9 102 N/A 2 33.35914 -114.72629 15 94 N/A 2 33.35489 -114.72756 13 93 N/A 2 33.35467 -114.72708 11 101 N/A 2 33.35921 -114.72623 15 78 N/A 2 33.35917 -114.72621 10 83 N/A 2 33.35922 -114.72614 15 84 N/A 2 33.35480 -114.72740 12 97 N/A 2 33.35479 -114.72755 13 84 N/A 2 33.35479 -114.72755 10 93 N/A 2 33.35299 -114.72734 8 97 N/A 2 33.35299 -114.72734 10 98 N/A 2 33.35328 -114.72743 12 92 N/A 2 33.35907 -114.72651 20 79 N/A 2 33.35906 -114.72648 16 95 N/A 2 33.35915 -114.72636 13 89 N/A 2 33.35482 -114.72772 20 90 N/A 2 33.35475 -114.72710 13 88 N/A 2 33.35481 -114.72756 10 97 N/A 2 33.35337 -114.72745 7 87 N/A 2 110 Latitude Longitude Dip Dip Simple Dune Thickness Surface Direction (cm) Order 33.35911 -114.72651 13 85 N/A 2 33.35318 -114.72736 16 90 N/A 2 33.35913 -114.72631 12 93 N/A 2 33.35867 -114.72668 14 98 N/A 2 33.35479 -114.72755 10 102 N/A 2 111 APPENDIX E BEDDING MEASUREMENTS (DATUM: WGS84); STRIKE/DIP FOLLOW RIGHT HAND RULE Latitude Longitude Strike Dip Facies 33.29334134 -114.7685605 25 8 Bioclastic Grainstone 33.29537735 -114.76512115 2 4 Bioclastic Grainstone 33.29537437 -114.76449863 329 5 Bioclastic Grainstone 33.29530837 -114.7645138 36 6 Bioclastic Grainstone 33.31260505 -114.74223286 358 5 Bioclastic Grainstone 33.29916806 -114.75978926 12 11 Bioclastic Grainstone 33.29407493 -114.77170522 15 7 Bioclastic Grainstone 33.29537735 -114.76512115 2 4 Bioclastic Grainstone 33.33637131 -114.72073437 167 6 Bioclastic Grainstone 33.31260505 -114.74223286 358 5 Bioclastic Grainstone 33.29530837 -114.7645138 36 6 Bioclastic Grainstone 33.29407493 -114.77170522 15 7 Bioclastic Grainstone 33.29537735 -114.76512115 2 4 Bioclastic Grainstone 33.33611914 -114.72151648 175 5 Bioclastic Grainstone 33.33633581 -114.72147734 211 5 Bioclastic Grainstone 33.41241757 -114.69667553 27 2 Bioclastic Grainstone 33.41241757 -114.69667553 37 3 Bioclastic Grainstone 33.35901276 -114.72673791 8 9 Bioclastic Grainstone 33.29537735 -114.76512115 2 4 Bioclastic Grainstone 33.29334134 -114.7685605 25 8 Bioclastic Grainstone 33.29921094 -114.76009268 11 21 Bioclastic Grainstone 33.29919841 -114.76006703 31 32 Bioclastic Grainstone 33.29925046 -114.76006385 30 29 Bioclastic Grainstone 33.29923893 -114.76005899 21 26 Bioclastic Grainstone 33.29916806 -114.75978926 12 11 Bioclastic Grainstone 33.29537437 -114.76449863 329 5 Bioclastic Grainstone 112 Latitude Longitude Strike Dip Facies 33.29530837 -114.7645138 36 6 Bioclastic Grainstone 33.29532861 -114.76472762 1 6 Bioclastic Grainstone 33.35865397 -114.72603492 350 3 Bioclastic Grainstone 33.35864161 -114.72607926 349 2 Bioclastic Grainstone 33.35903212 -114.72648134 356 3 Bioclastic Grainstone 33.35918081 -114.72644337 351 8 Bioclastic Grainstone 33.33633581 -114.72147734 211 5 Bioclastic Grainstone 33.33633581 -114.72147734 210 5 Bioclastic Grainstone 33.33637131 -114.72073437 167 6 Bioclastic Grainstone 33.33637123 -114.7207047 191 11 Bioclastic Grainstone 33.33699878 -114.72121314 142 15 Bioclastic Grainstone 33.3370396 -114.72121792 136 19 Bioclastic Grainstone 33.33703826 -114.72127374 140 19 Bioclastic Grainstone 33.33528732 -114.72281174 78 3 Bioclastic Grainstone 33.29407493 -114.77170522 15 7 Bioclastic Grainstone 33.29230034 -114.7736755 219 16 Bioclastic Grainstone 33.29230435 -114.7736797 224 23 Bioclastic Grainstone 33.29223234 -114.7735846 112 7 Bioclastic Grainstone 33.29233776 -114.7736421 121 8 Bioclastic Grainstone 33.29234606 -114.7736491 144 7 Bioclastic Grainstone 33.2923466 -114.7736413 122 12 Bioclastic Grainstone 33.29234814 -114.7736785 124 10 Bioclastic Grainstone 33.29235212 -114.7736735 140 12 Bioclastic Grainstone 33.29236214 -114.7736692 156 8 Bioclastic Grainstone 33.29236839 -114.7736538 154 8 Bioclastic Grainstone 33.29236078 -114.7736637 143 8 Bioclastic Grainstone 33.2918629 -114.7764816 99 6 Bioclastic Grainstone 33.2919358 -114.7764584 102 9 Bioclastic Grainstone 33.29192782 -114.7764561 100 8 Bioclastic Grainstone 33.29188818 -114.7764673 85 6 Bioclastic Grainstone 113 Latitude Longitude Strike Dip Facies 33.29184421 -114.7765077 30 6 Bioclastic Grainstone 33.29185063 -114.7764738 82 7 Bioclastic Grainstone 33.29186042 -114.7764869 63 8 Bioclastic Grainstone 33.29289291 -114.7716174 4 13 Bioclastic Grainstone 33.29289291 -114.7716174 350 21 Bioclastic Grainstone 33.29289291 -114.7716174 347 18 Bioclastic Grainstone 33.29289291 -114.7716174 359 20 Bioclastic Grainstone 33.29289291 -114.7716174 330 19 Bioclastic Grainstone 33.29289291 -114.7716174 338 12 Bioclastic Grainstone 33.29289291 -114.7716174 332 13 Bioclastic Grainstone 33.30166244 -114.7612532 232 18 Bioclastic Grainstone 33.30169501 -114.7612611 218 12 Bioclastic Grainstone 33.30164705 -114.7612657 210 16 Bioclastic Grainstone 33.30162896 -114.7612289 215 18 Bioclastic Grainstone 33.30161145 -114.7612241 24 7 Bioclastic Grainstone 33.30162549 -114.7612263 31 15 Bioclastic Grainstone 33.30160584 -114.761225 26 15 Bioclastic Grainstone 33.30163822 -114.761201 26 11 Bioclastic Grainstone 33.30168689 -114.7611678 42 14 Bioclastic Grainstone 33.301757 -114.7618128 13 2 Bioclastic Grainstone 33.30180807 -114.7618352 29 4 Bioclastic Grainstone 33.30174179 -114.7618145 27 2 Bioclastic Grainstone 33.30174889 -114.7618305 52 5 Bioclastic Grainstone 33.3017477 -114.7618281 356 2 Bioclastic Grainstone 33.30171856 -114.7618144 340 9 Bioclastic Grainstone 33.30170917 -114.761831 333 10 Bioclastic Grainstone 33.30170603 -114.7618655 359 8 Bioclastic Grainstone 33.30171077 -114.7618759 349 6 Bioclastic Grainstone 33.30170634 -114.7618645 12 9 Bioclastic Grainstone 33.30172628 -114.7618784 192 5 Bioclastic Grainstone 114 Latitude Longitude Strike Dip Facies 33.30174117 -114.7618631 162 9 Bioclastic Grainstone 33.30172206 -114.7618773 157 8 Bioclastic Grainstone 33.3017164 -114.7618946 183 10 Bioclastic Grainstone 33.30172942 -114.7618718 176 14 Bioclastic Grainstone 33.30175241 -114.7618324 170 17 Bioclastic Grainstone 33.30175221 -114.7618292 172 18 Bioclastic Grainstone 33.30173546 -114.7618265 160 20 Bioclastic Grainstone 33.30174795 -114.7618365 170 18 Bioclastic Grainstone 33.29537164 -114.765151 348 4 Bioclastic Grainstone 33.29535053 -114.7651487 57 3 Bioclastic Grainstone 33.29535341 -114.7651491 28 2 Bioclastic Grainstone 33.29532182 -114.7650552 53 16 Bioclastic Grainstone 33.29532032 -114.7650577 57 19 Bioclastic Grainstone 33.29533121 -114.7650332 56 23 Bioclastic Grainstone 33.2953133 -114.7650416 57 16 Bioclastic Grainstone 33.29531461 -114.7650457 47 16 Bioclastic Grainstone 33.29530986 -114.7650366 54 16 Bioclastic Grainstone 33.32087652 -114.736756 355 8 Bioclastic Grainstone 33.32039261 -114.7365388 14 6 Bioclastic Grainstone 33.32050692 -114.7365883 348 13 Bioclastic Grainstone 33.29546691 -114.7621652 59 36 Bioclastic Grainstone 33.29547971 -114.7621655 68 33 Bioclastic Grainstone 33.29547256 -114.762138 84 26 Bioclastic Grainstone 33.29546189 -114.7621183 100 18 Bioclastic Grainstone 33.29546235 -114.7621078 81 22 Bioclastic Grainstone 33.29553771 -114.7619751 355 25 Bioclastic Grainstone 33.29555946 -114.76203 14 30 Bioclastic Grainstone 33.29552322 -114.7619819 19 24 Bioclastic Grainstone 33.29550942 -114.7620092 53 33 Bioclastic Grainstone 33.29549239 -114.7620435 69 26 Bioclastic Grainstone 115 Latitude Longitude Strike Dip Facies 33.29549722 -114.7621049 62 25 Bioclastic Grainstone 33.29549056 -114.7621535 66 37 Bioclastic Grainstone 33.29550921 -114.7621539 66 33 Bioclastic Grainstone 33.29553159 -114.7621363 90 31 Bioclastic Grainstone 33.29552905 -114.7621109 87 29 Bioclastic Grainstone 33.30034232 -114.7600729 297 21 Bioclastic Grainstone 33.30034492 -114.7600738 323 22 Bioclastic Grainstone 33.30032845 -114.7600752 316 20 Bioclastic Grainstone 33.30033306 -114.7600933 320 24 Bioclastic Grainstone 33.30030116 -114.7600375 288 27 Bioclastic Grainstone 33.30030827 -114.7600525 288 27 Bioclastic Grainstone 33.30029384 -114.7600651 299 24 Bioclastic Grainstone 33.30177537 -114.7618764 178 11 Bioclastic Grainstone 33.30175741 -114.7618854 186 17 Bioclastic Grainstone 33.30176084 -114.7618482 159 18 Bioclastic Grainstone 33.30185843 -114.7621914 11 4 Bioclastic Grainstone 33.3017866 -114.7622135 22 11 Bioclastic Grainstone 33.30150876 -114.76322 285 2 Bioclastic Grainstone 33.41241757 -114.69667553 39 6 Green Claystone 33.41241757 -114.69667553 39 6 Green Claystone 33.41241757 -114.69667553 33 7 Green Claystone 33.41241757 -114.69667553 45 5 Heterolithic Facies 33.41241757 -114.69667553 95 6 Heterolithic Facies 33.35483534 -114.72762831 9 4 Heterolithic Facies 33.35915186 -114.72623616 5 3 Heterolithic Facies 33.33592426 -114.72377909 32 7 Heterolithic Facies 33.35324924 -114.72752715 1 7 Heterolithic Facies 33.41241757 -114.69667553 29 3 Heterolithic Facies 33.41241757 -114.69667553 37 2 Heterolithic Facies 33.41241757 -114.69667553 26 6 Heterolithic Facies 116 Latitude Longitude Strike Dip Facies 33.41241757 -114.69667553 323 4 Heterolithic Facies 33.41241757 -114.69667553 38 6 Heterolithic Facies 33.41241757 -114.69667553 22 2 Heterolithic Facies 33.41241757 -114.69667553 308 4 Heterolithic Facies 33.41241757 -114.69667553 30 6 Heterolithic Facies 33.41241757 -114.69667553 7 6 Heterolithic Facies 33.41241757 -114.69667553 42 6 Heterolithic Facies 33.41241757 -114.69667553 45 5 Heterolithic Facies 33.35479222 -114.72755393 64 7 Heterolithic Facies 33.35479222 -114.72755393 94 3 Heterolithic Facies 33.35479222 -114.72755393 94 3 Heterolithic Facies 33.35479222 -114.72755393 38 2 Heterolithic Facies 33.35479222 -114.72755393 74 5 Heterolithic Facies 33.35324924 -114.72752715 1 7 Heterolithic Facies 33.35915186 -114.72623616 5 3 Heterolithic Facies 33.35478975 -114.72776217 360 7 Heterolithic Facies 33.35483534 -114.72762831 9 6 Heterolithic Facies 33.35459751 -114.72726387 6 6 Heterolithic Facies 33.30208092 -114.7624066 23 5 Heterolithic Facies 33.3020978 -114.7624418 11 3 Heterolithic Facies 33.30209455 -114.7624317 46 3 Heterolithic Facies 33.30210887 -114.7624119 19 4 Heterolithic Facies 33.30209308 -114.7624028 27 4 Heterolithic Facies 33.30210105 -114.7623707 60 5 Heterolithic Facies 33.30205384 -114.7623778 53 4 Heterolithic Facies 33.35459751 -114.72726387 6 6 Heterolithic Facies 33.33592426 -114.72377909 32 7 Heterolithic Facies 33.2957667 -114.7653923 64 4 Heterolithic Facies 33.29569606 -114.7653429 50 6 Heterolithic Facies 33.29573717 -114.7654733 17 5 Heterolithic Facies 117 Latitude Longitude Strike Dip Facies 33.2957585 -114.7655232 41 3 Heterolithic Facies 33.29573708 -114.7654912 6 3 Heterolithic Facies 33.29581661 -114.765369 33 23 Heterolithic Facies 33.29583842 -114.7653751 47 6 Heterolithic Facies 33.29618687 -114.7667968 83 5 Heterolithic Facies 33.29619205 -114.7667993 39 3 Heterolithic Facies 33.29620557 -114.7667918 114 3 Heterolithic Facies 33.29620082 -114.7667856 48 3 Heterolithic Facies 33.29619892 -114.7667862 79 3 Heterolithic Facies 33.29618142 -114.7667759 84 4 Heterolithic Facies 33.29619749 -114.7668306 51 5 Heterolithic Facies 33.29619631 -114.7668237 66 5 Heterolithic Facies 33.29619767 -114.7668724 91 4 Heterolithic Facies 33.29619669 -114.7668835 74 5 Heterolithic Facies 33.2967167 -114.7670405 32 9 Heterolithic Facies 33.2967111 -114.7670802 38 8 Heterolithic Facies 33.29671915 -114.7670555 13 8 Heterolithic Facies 33.29673201 -114.7670554 11 7 Heterolithic Facies 33.2967384 -114.767002 70 4 Heterolithic Facies 33.29674882 -114.7669558 74 4 Heterolithic Facies 33.29674415 -114.7669495 95 6 Heterolithic Facies 33.29675075 -114.7669512 85 5 Heterolithic Facies 33.29675208 -114.7669494 80 5 Heterolithic Facies 33.29676332 -114.7669546 71 6 Heterolithic Facies 33.30549374 -114.7538809 19 9 Heterolithic Facies 33.30547201 -114.7538981 33 5 Heterolithic Facies 33.30544416 -114.7538834 112 1 Heterolithic Facies 33.3055135 -114.7540241 47 4 Heterolithic Facies 33.30516029 -114.7550061 61 4 Heterolithic Facies 33.30517381 -114.7550005 98 4 Heterolithic Facies 118 Latitude Longitude Strike Dip Facies 33.30514613 -114.7549816 70 4 Heterolithic Facies 33.3051434 -114.7549723 89 4 Heterolithic Facies 33.30513922 -114.7549829 81 4 Heterolithic Facies 33.30513609 -114.754991 65 6 Heterolithic Facies 33.3051291 -114.7549916 51 4 Heterolithic Facies 33.30512898 -114.7549841 34 5 Heterolithic Facies 33.30512629 -114.7549888 51 4 Heterolithic Facies 33.30713895 -114.7481669 359 3 Heterolithic Facies 33.30711906 -114.7481969 3 6 Heterolithic Facies 33.30695345 -114.7479986 40 5 Heterolithic Facies 33.30699386 -114.7480735 33 4 Heterolithic Facies 33.30709338 -114.7480849 24 5 Heterolithic Facies 33.30709727 -114.7481065 10 6 Heterolithic Facies 33.30708795 -114.7481292 7 4 Heterolithic Facies 33.30708999 -114.7481175 3 6 Heterolithic Facies 33.30710237 -114.7481802 23 6 Heterolithic Facies 33.30710047 -114.7481712 21 5 Heterolithic Facies 33.30707464 -114.7481633 9 5 Heterolithic Facies 33.30705664 -114.7481363 72 4 Heterolithic Facies 33.30704654 -114.7481401 31 6 Heterolithic Facies 33.30706441 -114.7481522 24 5 Heterolithic Facies 33.30707419 -114.7481519 27 4 Heterolithic Facies 33.31157759 -114.7421445 43 5 Heterolithic Facies 33.30949522 -114.7450357 27 5 Heterolithic Facies 33.31237961 -114.7412016 19 2 Heterolithic Facies 33.31205648 -114.7415502 89 7 Heterolithic Facies 33.31206869 -114.7415451 94 8 Heterolithic Facies 33.31232628 -114.7440408 356 3 Heterolithic Facies 33.31233363 -114.7440306 352 3 Heterolithic Facies 33.31233302 -114.744043 26 5 Heterolithic Facies 119 Latitude Longitude Strike Dip Facies 33.31236227 -114.7440753 18 5 Heterolithic Facies 33.31230849 -114.7439903 23 5 Heterolithic Facies 33.31230671 -114.7439875 49 6 Heterolithic Facies 33.31226055 -114.7439528 67 7 Heterolithic Facies 33.31223806 -114.7439658 3 4 Heterolithic Facies 33.31227244 -114.7439911 346 4 Heterolithic Facies 33.32042668 -114.7370554 21 5 Heterolithic Facies 33.3203748 -114.7370791 9 7 Heterolithic Facies 33.32062881 -114.7369897 357 11 Heterolithic Facies 33.32062013 -114.7369681 357 8 Heterolithic Facies 33.32062502 -114.7369896 22 10 Heterolithic Facies 33.32061735 -114.7369814 25 7 Heterolithic Facies 33.32058023 -114.7369245 5 6 Heterolithic Facies 33.32053736 -114.736902 353 3 Heterolithic Facies 33.32054909 -114.7369708 33 7 Heterolithic Facies 33.30152188 -114.7632462 4 6 Heterolithic Facies 33.30154452 -114.7632065 141 6 Heterolithic Facies 33.30142097 -114.7632252 81 4 Heterolithic Facies 33.30155026 -114.7632644 2 4 Heterolithic Facies 33.30151964 -114.7632306 324 6 Heterolithic Facies 33.41241757 -114.69667553 23 3 Red MS/Siltstone 33.29403465 -114.75639132 27 10 Red MS/Siltstone 33.29403465 -114.75639132 27 10 Red MS/Siltstone 33.30047735 -114.7421773 26 7 Red MS/Siltstone 33.30047842 -114.7421734 48 10 Red MS/Siltstone 33.30045095 -114.7421839 32 7 Red MS/Siltstone 33.30042956 -114.7421751 48 8 Red MS/Siltstone 33.30046644 -114.7421838 47 6 Red MS/Siltstone 33.29339126 -114.76855455 28 6 Reworked Conglomerate 33.34892442 -114.72953964 339 58 Tv 120 Latitude Longitude Strike Dip Facies 33.34892442 -114.72953964 339 58 Tv 33.30117572 -114.7724227 346 39 Tv 33.30122484 -114.7724182 355 47 Tv 33.30122551 -114.7724743 357 55 Tv 33.30120394 -114.7724773 355 57 Tv 33.31539547 -114.74147455 52 13 UBM 33.29289858 -114.7716139 7 125 UBM 33.29289868 -114.771636 8 134 UBM 33.29486856 -114.7669698 44 8 UBM 33.29485064 -114.7669498 46 6 UBM 33.29481946 -114.7668464 46 6 UBM 33.29474443 -114.7668726 38 7 UBM 33.29481398 -114.7668645 15 5 UBM 33.29482367 -114.7668584 42 6 UBM 33.30144013 -114.7599591 344 5 Upper Marl 33.30147128 -114.7599686 1 4 Upper Marl 33.30145459 -114.7599862 343 5 Upper Marl 33.30142297 -114.759962 343 5 Upper Marl 33.30142809 -114.7599467 348 6 Upper Marl 33.30139209 -114.7599128 338 7 Upper Marl 33.30139691 -114.7599398 325 7 Upper Marl 33.29478249 -114.7670179 42 6 Upper Marl 33.29481811 -114.7669522 44 6 Upper Marl 33.29477241 -114.7668693 37 4 Upper Marl 33.29471349 -114.7668937 31 5 Upper Marl 33.29481185 -114.7672068 63 5 Upper Marl 121 REFERENCES CITED Ainsworth, R.B., Hasiotis, S.T., Amos, K.J., Krapf, C.B.E., Payenberg, T.H.D., Sandstrom, M.L., Vakarelov, B.K., Lang, S.C., 2012. 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