Structure and Holocene evolution of an active creeping thrust fault: The Chihshang fault at Chinyuan (Taiwan)

NCUIR > College of Earth Sciences > Graduate Institute of Applied Geology > journal & Dissertation > Item 987654321/50611

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/50611

Title:	Structure and Holocene evolution of an active creeping thrust fault: The Chihshang fault at Chinyuan (Taiwan)
Authors:	Mu,CH;Angelier,J;Lee,JC;Chu,HT;Dong,JJ
Contributors:	應用地質研究所
Keywords:	LONGITUDINAL VALLEY FAULT;SAN-ANDREAS FAULT;EASTERN TAIWAN;CHENGKUNG EARTHQUAKE;PLATE BOUNDARY;SUTURE ZONE;DEFORMATION;CREEPMETER;COLLISION;INVERSION
Date:	2011
Issue Date:	2012-03-27 17:37:53 (UTC+8)
Publisher:	國立中央大學
Abstract:	We conducted a variety of measurements and analyses at Chihshang Active Fault Observatory in eastern Taiwan, including surface-rupture mapping, three shallow borehole core analysis and kinematic analysis of geodetic measurements. We found that the Chihshang fault exhibits a three-branch fault system in the Chinyuan alluvial fan, which is composed of at least 100 m thick gravel deposits. Outside of the Chinyuan River, the Chihshang fault shows a single fault system with a sharp lithological contact. Combining the leveling results and trench excavation, we interpret that the three fault branches are coupled with a 50-60-m-wide pop-up structure in the hangingwall. Based on the ratio between vertical and horizontal displacements, we obtained dip angles of 38 degrees, 62 degrees and 16 degrees for two west-vergent thrusts and an east-vergent backthrust, respectively. This pop-up was estimated to develop at the uppermost 30-40 m unconsolidated gravels during the last few thousand years above the main fault with a dip angle of 42 degrees. By compiling the available ages data, we obtained an uplift rate of 2.3 cm/yr of the Chihshang fault and an alluvial sedimentation rate of 1.1 cm/yr during the past thousands years. Consequently, the individual uplift rate for each fault branch at the Chihshang Observatory was slightly less than the deposition rate of the Chinyuan River. No geomorphic fault scarp can thus be observed in the three-branch fault system area. (C) 2011 Elsevier Ltd. All rights reserved.
Relation:	JOURNAL OF STRUCTURAL GEOLOGY
Appears in Collections:	[Graduate Institute of Applied Geology] journal & Dissertation

Files in This Item:

File	Description	Size	Format
index.html		0Kb	HTML	800	View/Open

社群 sharing

Loading...