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

Detection of a weak late-stage deformation event in granitic gneiss through anisotropy of magnetic susceptibility: implications for tectonic evolution of the Bomdila Gneiss in the Arunachal Lesser Himalaya, Northeast India

“…The magnetic foliation may define an intermediate plane in between the ‘S-’ and ‘C-plane’ (Aranguren, Cuevas & Tubia, 1996; Tomezzoli, Mcdonald & Tickyj, 2003) or may mimic a fabric that has developed during a late stage of progressive deformation (Ono et al 2010). Sen et al (2012) have shown large variations in the relationship between the magnetic and corresponding mesoscopic foliation for the Lesser Himalayan Proterozoic granitic gneisses of the Himachal Himalaya. They suggested superposed folding of non-cylindrical folds due to large variation in fold hinge line trends as a possible cause for the development of a composite magnetic and outcrop-scale fabric.…”

“…However, the magnetic fabric of granitic gneiss in a polydeformed terrane can be difficult to correlate with any corresponding mesoscopic fabric. In the Himalaya, interpretation of the magnetic fabric of granitoids is far from straightforward as these granitoids are usually affected by numerous post-emplacement deformation events (Jayangondaperumal, Dubey & Sen, 2010; Tripathi, Sen & Dubey, 2012; Sen et al 2012). Past studies have shown that a deformed granite or granitic gneiss may give a magnetic fabric intermediate to the visible ‘S’ and ‘C’ fabric (Aranguren, Cuevas & Tubia, 1996; Tomezzoli, Mcdonald & Tickyj, 2003) or correspond to some fabric developed during a late stage of deformation (Ono et al 2010).…”

Geochemistry of meta‐sediments from Neoproterozoic Shimla and Chail Groups of Outer Lesser Himalaya: Implications for provenance, tectonic setting, and paleo‐weathering conditions

“…The Lesser Himalaya is thrusted over the Higher Himalaya Crystalline Sequence (HHCS) along the Main Central Thrust (MCT; Figure 1a). The HHCS, which forms the core of the Himalaya, consists of medium‐ to high‐grade metamorphic rocks which are intruded by Palaeozoic to Mesozoic leucogranite melts (Pant et al, 2006; Parrish & Hodges, 1996; Sen, Dubey, Tripathi, & Pfänder, 2012). The South Tibetian Detachment (STD) separates the Higher Himalayan rocks from the typically unmetamorphosed (or low‐grade) Neoproterozoic to Eocene sedimentary rocks of Tethyan Himalaya (Law et al, 2013).…”

“…The South Tibetian Detachment (STD) separates the Higher Himalayan rocks from the typically unmetamorphosed (or low‐grade) Neoproterozoic to Eocene sedimentary rocks of Tethyan Himalaya (Law et al, 2013). These Tethyan meta‐sediments are followed in the north by the Indus Tsangpo Suture Zone which marks the collision boundary between India and Asia (Sen et al, 2012).…”

Mesoscopic, magnetic and petrofabric study of the High Himalayan gneisses and leucogranite along oblique and frontal ramps of the Vaikrita Thrust in Satluj and Bhagirathi valleys: Thrust locking and superposed folding

“…Earlier studies carried out by Aranguren et al (1996) and Tomezzolli et al (2003) have shown that magnetic fabric for granitic mylonites or granitic gneiss may represent an intermediate fabric between 'S' and 'C' fabrics or depict a weak fabric developed at later stages of deformation (Ono et al 2010). In the case of Himalaya, a complexly deformed terrene, comparison between the magnetic fabric and their corresponding mesoscopic foliation is important as it can reveal multiple deformation events (Jayangondaperumal et al 2010;Sen et al 2012;Tripathi et al 2012;Singh et al 2017).…”