Tectonics of the SW margin of the Nanga Parbat–Haramosh massif
Published:January 01, 2000
M. A. Edwards, W. S. F. Kidd, M. A. Khan, D. A. Schneider, 2000. "Tectonics of the SW margin of the Nanga Parbat–Haramosh massif", Tectonics of the Nanga Parbat Syntaxis and the Western Himalaya, M. Asif Khan, Peter J. Treloar, Michael P. Searle, M. Qasim Jan
Download citation file:
We present an analysis of the tectonic evolution of the southwestern portions of the Nanga Parbat massif, Pakistan Himalaya, based upon detailed mapping and structural analyses from the Bunar, Biji, Diamir, Airl, Niat and SW Rupal valleys. Mainly metasedimentary cover rocks of the Indian plate are divided into upper and lower cover. There is a marked structural thinning of the cover in the main Bunar valley from south to north, and this is attributed to a major frontal ramp in the original Main Mantle Thrust (MMT). A hitherto unmapped shear zone, the Diamir Shear Zone, is identified, that is associated with a syn-kinematically intruded belt of granitic rocks, the Jalhari Granite. The shear zone is a several kilometre thick, generally W-vergent, ductile to brittle shear zone that is associated with local overturning of the entire MMT section, typified by the Gashit Fold. 40Ar/39Ar cooling ages from across the area indicate a steep cooling age gradient across the Diamir Shear Zone from > 40 to < 5 Ma. The Diamir Shear Zone is mechanically linked to part of the Raikhot Fault System and, together, they are seen to be a crustal-scale reverse fault that has allowed relative uplift and overthrusting of the core of Nanga Parbat.
Figures & Tables
Tectonics of the Nanga Parbat Syntaxis and the Western Himalaya
The western syntaxis of the Himalaya is one of the most exciting frontiers of continental tectonis studies. The region around the mountain of Nanga Parbat has some of the highest peaks, deepest valleys and highest uplift, exhumation and erosion rates known on earth. Surrounding regions include the Hindu Kush and Karakoram mountains (Asian plate), the Kohistan island arc and the Ladakh and Zanskar ranges of the western Himalaya (Indian plate). This volume includes 24 papers on all these regions as well as five new fold-out maps of the eastern Hindu Kush, the Spontang Ophiolite region of Ladakh, part of the west margin of the Indian plate, the Indus syntaxis in Pakistan and the Bouguer gravity anomalies in Pakistan.