Earth Sciences Graduate Student Research

Permanent URI for this collection

Now showing 1 - 1 of 1

Open Access
Extremely rapid up-and-down motions of island arc crust during arc-continent collision
(Springer Nature, 2022-03) Lai, Larry Syu-Heng; Yen, Jiun-Yee; Dorsey, Rebecca J.; Horng, Chorng-Shern; Chi, Wen-Rong; Shea, Kai-Shuan
Mountain building and the rock cycle often involve large vertical crustal motions, but their rates and timescales in unmetamorphosed rocks remain poorly understood. We utilize high-resolution magneto-biostratigraphy and backstripping analysis of marine deposits in an active arc-continent suture zone of eastern Taiwan to document short cycles of vertical crustal oscillations. A basal unconformity formed on Miocene volcanic arc crust in an uplifting forebulge starting ~6 Ma, followed by rapid foredeep subsidence at 2.3–3.2 mm yr−1 (~3.4–0.5 Ma) in response to oceanward-migrating flexural wave. Since ~0.8–0.5 Ma, arc crust has undergone extremely rapid (~9.0–14.4 mm yr−1) uplift to form the modern Coastal Range during transpressional strain. The northern sector may have recently entered another phase of subsidence related to a subduction polarity reversal. These transient vertical crustal motions are under-detected by thermochronologic methods, but are likely characteristic of continental growth by arc accretion over geologic timescales.