The exhumation history of the middle Hsuehshan Range, Taiwan, as revealed by zircon thermochronological modeling

Shyu, C. J., Tan, E., Kirstein, L. A., Stuart, F. M. and Chen, Y.-G. (2023) The exhumation history of the middle Hsuehshan Range, Taiwan, as revealed by zircon thermochronological modeling. Tectonophysics, 860, 229907. (doi: 10.1016/j.tecto.2023.229907)

Abstract

The Taiwan orogenic belt has high precipitation and high exhumation rates (3–6 km/Myr), making it a natural laboratory for understanding how erosion, tectonics, and climate interact. Understanding how rock exhumation rates have evolved since the late Miocene is key to unraveling climate–tectonic interactions. In this study, we present 8 new zircon fission track (ZFT) and (Usingle bondTh)/He (ZHe) cooling ages (including 2 unreset ages) from 5 samples from 1700 to over 3300 m elevation around the highly incised Dajia River in the core of the Hsuehshan Range (termed the mid-HR in this study) in central Taiwan. Two of the ZFT and ZHe ages (5.3 Ma and 2.6 Ma) are the oldest ages recorded in this region. These ages suggest that the cooling rate of the mid-HR is lower than that of the Backbone Range and Yushan. With these and previously published cooling ages, we modeled the exhumation and cooling history using a 2-D thermal diffusion equation with time-varying erosion. The ZFT and ZHe ages are best explained by a steadily increasing exhumation rate up to 3.4 + 0.5/−0.3 km/Myr from 7 to 1 Ma. The exhumation rate in the last million years is not as well constrained but appears to have increased at a slower rate. Our findings differ from those of previous studies that propose that the exhumation rate increased rapidly in the last 1–2 Myr. We propose that the steady increase in the exhumation rate in the mid-HR indicates increasing topographic relief, which is likely caused by progressive crustal thickening.

• Item Type: Articles
• Additional Information: The authors would like to thank MOST, Taiwan for funding (110-2116-M-001-005).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Stuart, Professor Fin

Creator Roles

Stuart, F. M.: Data curation, Methodology, Writing – review and editing

• Authors: Shyu, C. J., Tan, E., Kirstein, L. A., Stuart, F. M., and Chen, Y.-G.
• College/School: College of Science and Engineering > Scottish Universities Environmental Research Centre
• Journal Name: Tectonophysics
• Publisher: Elsevier
• ISSN: 0040-1951
• ISSN (Online): 1879-3266
• Published Online: 16 May 2023
• Copyright Holders: Copyright © 2023 Elsevier B.V.
• First Published: First published in Tectonophysics 860: 229907
• Publisher Policy: Reproduced in accordance with the publisher copyright policy