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Stress field evolution in the northwest Himalayan syntaxis, northern Pakistan
Author(s) -
Pêcher A.,
Seeber L.,
Guillot S.,
Jouanne F.,
Kausar A.,
Latif M.,
Majid A.,
Mahéo G.,
Mugnier J. L.,
Rolland Y.,
van der Beek P.,
Van Melle J.
Publication year - 2008
Publication title -
tectonics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.465
H-Index - 134
eISSN - 1944-9194
pISSN - 0278-7407
DOI - 10.1029/2007tc002252
Subject(s) - geology , stress field , fault (geology) , seismology , tectonics , wrench , paleontology , physics , finite element method , thermodynamics , mechanical engineering , engineering
We have conducted a systematic inversion of striated fault planes throughout northern Pakistan in order to better depict the temporal and spatial variations in stress patterns. Two domains are evidenced at a regional scale, separated by the active Raikhot fault, the western boundary of the Nanga Parbat spur. West of this fault, a wrench‐type stress field with σ 1 axis oriented around N–S predominates in the Karakorum and in Kohistan. It predates Pliocene‐Quaternary exhumation of Nanga Parbat and corresponds to the Miocene or earlier regional stress field related to Indian‐Asian convergence. East of the Raikhot fault, compression parallel to the belt accounts for initiation of the Nanga Parbat anticlinorium after 5 Ma. It is followed by predominant post‐2 Ma extension, both parallel to the belt and NNE–SSW oriented. Thus, in the N–W Himalayan syntaxis, multidirectional extension is juxtaposed on short timescales to shortening either parallel or perpendicular to the belt. Such juxtaposition could be characteristic of strain and stress partitioning during oblique convergence.