Evolution of normal faults within the Higher Himalaya - local phenomenon or regional trend?
Final Report Abstract
The structural and geochronological results generated in this study furnishes a genuinely new dataset on the deformation history in the NW Indian Himalaya, which helps to better understand the kinematic evolution of high-elevation sectors of tectonically active mountain belts. In the southern and western part of the study area, brittle faulting records mainly NE-SW oriented shortening perpendicular to the strike of the orogeny, associated with strike-slip faulting. NE-SW oriented extension parallel to shortening characterizes a subsequent phase, affecting approximately the same area. NW-SE oriented extension affects almost the entire study area and cross-cuts structures related to NE-SW extension. In the vicinity of the Leo Pargil gneiss dome, the extension direction is parallel to the ESE oriented exhumation of the dome, but also coupled with strike-slip faulting along reactivated faults. The most recent deformation phase, however, is characterized by pervasive E-W extension, overprinting and reactivating all previously generated structures, while contractional deformation governs the peripheral sectors of the orogen. This is compatible with available seismicity records and GPS measurements. Our data set, however, shows that E-W extension occurs in a much more lager region towards the south and west than the seismicity data would suggest. Importantly, based on our new 40Ar/39Ar data on synkinematic muscovites obtained in the fault planes of normal faults the regional extensional processes must have begun between 16 and 14 Ma.
Publications
- 2010. E-W extension in the Northwestern Indian Himalaya. Geol. Soc. America Bulletin, 122 (9/10), p. 1499-1515
Hintersberger, E., Thiede, R., Strecker, M., Hacker, B.
- 2011. The role of extension during brittle deformation within the NW Indian Himalaya. Tectonics, 30
Hintersberger, E., Thiede, R., Strecker, M.
(See online at https://doi.org/10.1029/2010TC002822) - 2013. The role of extension during the evolution of the NW Indian Himalaya. PhD thesis, Universität Potsdam
Hintersberger, Esther
