Cenozoic Stratigraphy of the Owyhee Region, Southeastern Oregon
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Date
1965-12
Authors
Kittleman, Laurence R.
Green, Arthur R.
Hagood, Allen R.
Johnson, Arvid M.
McMurray, Jay M.
Russell, Robert G.
Weeden, Dennis A.
Journal Title
Journal ISSN
Volume Title
Publisher
Museum of Natural History, University of Oregon
Abstract
Late Cenozoic terrestrial sedimentation and volcanism
produced more than 6000 ft of complexly
interstratified rocks in the Owyhee region, southeastern
Oregon. Deposition upon a basement of
peripherally exposed Paleozoic and Mesozoic rocks
began in Miocene time and continued intermittently
through the Pleistocene. High-angle block faulting
related to the adjacent Basin and Range Province
created hundreds to thousands of feet of structural
relief. Faulting and concomitant erosion formed
north-trending basins that received Miocene, Pliocene,
and Pleistocene deposits.
The rocks described range from late Miocene to
sub-historic. They are dated through mammalian
chronology, stratigraphic relations, and potassium·
argon chronology. About 30 stratigraphic units are
discussed, of which 12 are named and defined. Extrusive
rocks are olivine-poor clinopyroxene basalts,
porphyritic andesine rhyolites, and rhyolitic welded
ash-flow tuffs. Clastic rocks are arkoses, granite-cobble
conglomerates, air-fall tuffs, and fluviatile
and lacustrine bentonitic volcaniclastic rocks variously
adulterated with plutonic detritus.
Description
54 pages
Keywords
Cenozoic, Volcano, Owyhee, Miocene, Paleozoic, Pleistocene