TY  - JOUR
A1  - Wilke, Franziska Daniela Helena
A1  - Sobel, Edward
A1  - O'Brien, Patrick J.
A1  - Stockli, Daniel F.
T1  - Apatite fission track and (U-Th)/He ages from the Higher Himalayan Crystallines, Kaghan Valley, Pakistan: Implications for an Eocene Plateau and Oligocene to Pliocene exhumation
JF  - Journal of Asian earth sciences
N2  - Apatite fission track and apatite and zircon (U-Th)/He ages were obtained from high- and ultra high-pressure rocks from the Kaghan Valley, Pakistan. Four samples from the high altitude northern parts of the valley yielded apatite fission track ages between 24.5 +/- 3.7 and 15.6 +/- 2.1 Ma and apatite (U-Th)/He ages between 21.0 +/- 0.6 and 5.3 +/- 0.2 Ma. These data record cooling of the formerly deeply-subducted high-grade metamorphic rocks induced by denudation and exhumation consistent with extension and back sliding along the reactivated, normal-acting Main Mantle Thrust. Overlap at around 10 Ma between fission track and (U-Th)/He ages is recognised at one location (Besal) showing that fast cooling occurred due to brittle reactivation of a former thrust fault. Widespread Miocene cooling is also evident in adjacent areas to the west (Deosai Plateau, Tso Moran), most likely related to uplift and unroofing linked to continued underplating of the Indian lower crust beneath Ladakh and Kohistan in the Late Eocene to Oligocene. In the southernmost part of the study area, near Naran, two significantly younger Late Miocene to Pliocene apatite fission track ages of 7.6 +/- 2.1 to 4.0 +/- 0.5 Ma suggest a spatial and temporal separation of exhumation processes. These younger ages are best explained by enhanced Late Miocene uplift and erosion driven by thrusting along the Main Boundary Thrust.
KW  - NW Himalaya
KW  - Kaghan Valley
KW  - Thermochronology
KW  - AFT
KW  - (U-Th)/He
KW  - Cooling rates
Y1  - 2012
U6  - https://doi.org/10.1016/j.jseaes.2012.06.014
SN  - 1367-9120
VL  - 59
IS  - 3
SP  - 14
EP  - 23
PB  - Elsevier
CY  - Oxford
ER  -