Anisotropy of magnetic susceptibility and petrofabric studies in the Garhwal synform, Outer Lesser Himalaya: Evidence of pop‐up klippen

Abstract

Geological field, petrographic, and anisotropy of magnetic susceptibility studies help in understanding the evolutionary history of the Garhwal synform that lies in the western Outer Lesser Himalaya. Orientations of the magnetic susceptibility axes reveal large variations at short distances as a result of superimposed deformation, and predominant stress conditions favorable for normal faulting. Rocks forming the outer limbs of the Garhwal Synform are metamorphosed up to the lower greenschist facies. The metamorphic grade increases to chlorite zone in the inner limb and the core is characterized by chlorite-biotite to garnet zones. The different grades of metamorphism are separated by thrusts and the structure is described as a pop-up klippen.i ar_628 428..443

Role of inversion tectonics in structural development of the Himalaya

“…The second type is known as parautochthonous klippe (e.g. Satengal, Banali and Garhwal klippen in the Garhwal Himalaya; Jayangondaperumal and Dubey, 2001;Devrani and Dubey, 2008) which show smaller horizontal and larger sub vertical fault displacement. This type of klippe lies over its root and form as pop-up structure.…”

“…The exposed large-scale fold structures are polyharmonic and normally show a rounded profile (e.g. Dubey and Bhat, 1991;Thakur, 1992;Devrani and Dubey, 2008) but the subsurface folds are sometimes shown with typical kink band geometry without any second order folds (e.g. Powers et al, 1998) so that the structures can be used for palinspastic reconstruction.…”

Composite mesoscopic and magnetic fabrics of the Paleo-Proterozoic Wangtu Gneissic Complex, Himachal Himalaya, India: Implications for ductile deformation and superposed folding of the Himalayan basement rocks

“…On the northern margin, the Siwalik rocks are separated from the Lesser Himalaya by the Main Boundary Thrust (MBT). The Lesser Himalayan rocks consist of metasediments with a large number of pop-up and allochthonous klippen (Jayangondaperumal and Dubey, 2001;Devrani and Dubey, 2008). The Lesser Himalaya is followed by the High Himalaya which is characterized by two prominent thrusts, i.e.…”

Structural and magnetic fabric studies of recess structures in the western Himalaya: Implications for 1905 Kangra earthquake

“…The maximum intensity was reported near Kangra and Dharamsala (trailing frontal ramp of Kangra is critical, because most of the earthquakes in the Himalaya have occurred along this structure (e.g. Gupta and Gupta, 1995;Mandal et al 2002;Devrani and Dubey, 2009). The detailed description of evolution of structural features formed and encountered in the area can be found in Dubey et al (2004) and Jayangondaperumal and Dubey (2001).…”