Title

Low-temperature thermal history along the Zanskar normal fault, Greater Himalayan Range, NW, India

Presenter Information

Brett Shurtleff

Document Type

Oral Presentation

Location

SURC Ballroom C/D

Start Date

16-5-2013

End Date

16-5-2013

Abstract

The Zanskar fault is a moderately northeast-dipping northwest-striking normal fault bounding the northern flank of the Greater Himalaya Range, NW Himalaya and is the westernmost segment of the South Tibetan Detachment System, an extensive normal fault structure that spans the length of the Himalayan orogen. The Zanskar fault is unique in that this extensional fault has developed within the India-Asia continent-continent collision zone. Detailed new (U-Th)/He zircon and apatite thermochronometric data from the High Himalayan crystalline rocks in the footwall of the Zanskar fault, provide constraints on the middle Miocene to present-day exhumation and normal slip histories along the fault. Inverse modeling of (U-Th)/He zircon and apatite thermochronometric data from the footwall of the Zanskar fault yield age patterns that are interpreted as indicating: (1) initiation of normal fault slip at ~14-13 Ma and rapid exhumation of the footwall between ~14 and 11 Ma at rates of 0.5-2.5 mm/yr, (2) rapid thermal re-equilibration between ~11 and 9 Ma, (3) slow exhumation and possibly a second stage of renewed extension between ~7 and 4 Ma indicated by increased cooling rates of some time-temperature paths, (4) continued slow exhumation and/or quiescence to the present day. The pulse of rapid cooling of footwall rocks to the Zanskar fault at ~14 Ma and possibly at ~7 Ma appear to broadly coincide with postulated continental slab break-off episodes to ~600 km beneath the western Himalaya, a mechanism that can result in an increase in gravitational potential energy and extensional deformation.

Poster Number

61

Faculty Mentor(s)

Jeffrey Lee, Christian Hager

Additional Mentoring Department

Geological Sciences

Additional Mentoring Department

Geology, University of Kansas, Lawrence, Kansas

This document is currently not available here.

Share

COinS
 
May 16th, 8:20 AM May 16th, 10:50 AM

Low-temperature thermal history along the Zanskar normal fault, Greater Himalayan Range, NW, India

SURC Ballroom C/D

The Zanskar fault is a moderately northeast-dipping northwest-striking normal fault bounding the northern flank of the Greater Himalaya Range, NW Himalaya and is the westernmost segment of the South Tibetan Detachment System, an extensive normal fault structure that spans the length of the Himalayan orogen. The Zanskar fault is unique in that this extensional fault has developed within the India-Asia continent-continent collision zone. Detailed new (U-Th)/He zircon and apatite thermochronometric data from the High Himalayan crystalline rocks in the footwall of the Zanskar fault, provide constraints on the middle Miocene to present-day exhumation and normal slip histories along the fault. Inverse modeling of (U-Th)/He zircon and apatite thermochronometric data from the footwall of the Zanskar fault yield age patterns that are interpreted as indicating: (1) initiation of normal fault slip at ~14-13 Ma and rapid exhumation of the footwall between ~14 and 11 Ma at rates of 0.5-2.5 mm/yr, (2) rapid thermal re-equilibration between ~11 and 9 Ma, (3) slow exhumation and possibly a second stage of renewed extension between ~7 and 4 Ma indicated by increased cooling rates of some time-temperature paths, (4) continued slow exhumation and/or quiescence to the present day. The pulse of rapid cooling of footwall rocks to the Zanskar fault at ~14 Ma and possibly at ~7 Ma appear to broadly coincide with postulated continental slab break-off episodes to ~600 km beneath the western Himalaya, a mechanism that can result in an increase in gravitational potential energy and extensional deformation.