Orogen-parallel, active left-slip faults in the eastern Himalaya; implications for the growth mechanism of the Himalayan Arc

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doi: 10.1016/j.epsl.2008.07.043
Authors:Li Dewei; Yin, An
Author Affiliations:Primary:
China University of Geosciences, Faculty of Earth Sciences, Wuhan, China
Other:
University of California, Los Angeles, United States
Volume Title:Earth and Planetary Science Letters
Source:Earth and Planetary Science Letters, 274(1-2), p.258-267. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0012-821X
Publication Date:2008
Note:In English. 41 refs.; illus., incl. 2 tables, geol. sketch maps
Summary:One of the key issues about the evolution of the Himalayan orogen is how its map-view curvature has changed with time. Some researchers propose that the arc curvature has decreased due to arc-perpendicular rifting while others suggest that it has increased due to arc-parallel strike-slip faulting. To quantify this problem we conducted field mapping, geomorphologic analysis of active structures, and dating of Pliocene-Quaternary sedimentary units in southeastern Tibet. This study reveals the existence of a ≈100-km wide and >500-km long, east-striking left-slip fault zone in the eastern Himalaya. The left-slip faults initiated prior to 3-4 Ma and have a total left-slip rate of 4-8 mm/yr across the fault zone. Although the left-slip rate in the eastern Himalaya is broadly comparable to the right-slip rate across the western Himalayan arc, the distributed and short-segmented geometry of left-slip faulting in the eastern Himalaya contrasts sharply to the discrete geometry of right-slip faulting in the western Himalaya. The different geometry may have resulted from an earlier initiation and a greater magnitude of fault motion on the right-slip faults, which implies that asymmetric eastward extrusion of western Tibet across the Himalayan arc was a dominant process in the earlier Himalayan history. This was replaced by oroclinal bending since 4 Ma, producing symmetric right-slip and left-slip faulting in the western and eastern Himalaya, respectively. Abstract Copyright (2008) Elsevier, B.V. [G.L.B.]
Sections:Physical properties of rocks and minerals
Subjects:Active faults; Faults; Geometry; Geomorphology; Lateral faults; Left-lateral faults; Neotectonics; Oroclines; Orogenic belts; Right-lateral faults; Sedimentary cover; Segmentation; Strike-slip faults; Tectonics; Asia; China; Far East; Himalayas; Tibetan Plateau; Xizang China; Central Gongzuo Fault; Himalayan Arc; North Comuzhelin Fault; North Gongzuo Fault; Oroclinal bending; South Comuzhelin Fault; Gongzuo Fault
Coordinates:N280000 N283000 E0883000 E0870000
Abstract Numbers:08M/3825
Record ID:2009016902
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands
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