Thrust Shear Sense and Shear Zone Fabrics in the Higher Himalaya, Siyom Valley, Eastern Arunachal Himalaya, India

Brittle tectonics in the western Arunachal Himalayan frontal fold belt, northeast India: Change in stress regime from pre‐collisional extension to collisional compression

“…After the development of MBT‐2, ~E‐W extension represents active Himalayan deformation of arc‐parallel extension north of MFT. If the arc‐parallel extension is coupled with the model of oblique convergence and clockwise rotation of the Indian plate, a stress regime can be interpreted for the formation of Kopili and Bomdila faults in the region in phases (Figure 12; Goswami, Baruah, et al, 2020; Goswami, Mahanta, et al, 2020). Published age 40 Ar/ 39 Ar dating of micas and (U–Th)/He dating of apatite from the Ama Drime Massif in southern Tibet suggests inception of arc‐parallel extension in Himalaya at 13–12 Ma and this age coincides with the cessation of activity along with MCT and south Tibet Detachment (STD) locally (Jessup et al, 2008; Kali et al, 2010).…”

“…This may be due to continued thrusting and thrust loading made σ 2 subvertical (Fossen, 2016). Bomdila faults in the region in phases (Figure 12; Goswami, Baruah, et al, 2020;. Published age 40 Ar/ 39 Ar dating of micas and (U-Th)/He dating of apatite from the Ama Drime Massif in southern Tibet suggests inception of arcparallel extension in Himalaya at 13-12 Ma and this age coincides with the cessation of activity along with MCT and south Tibet Detachment (STD) locally (Jessup et al, 2008;Kali et al, 2010).…”

“…The Lesser Himalayan Sequence in the Arunachal Himalaya is well studied and has been reviewed by several workers (Bhattacharya & Nandy, 2007; Bhusan, Bindal, & Aggarwal, 1991; de Sarkar, Mathew, & Pande, 2013; DeCelles et al, 2016; Goswami, Baruah, Mahanta, Kalita, & Borah, 2020; Goswami, Bhowmik, & Dasgupta, 2009; Goswami, Bhowmik, Dasgupta, & Pant, 2014; Kumar, 1997; Ray, 1995; Ray, Bandyopadhyay, & Razdan, 1989; Saha, 2013; Sarma, Bhattacharyya, Nandy, Konwar, & Mazumdar, 2014; Singh et al, 2017; Singh & Gururajan, 2011; Singh & Singh, 1983; Srivastava, Srivastava, Srivastava, & Singh, 2011; Yin, 2006; Yin et al, 2006, 2010a, 2010b). However, the deformation in the Gondwana sequence within the two splays of the MBT received scanty attention.…”

Basement cross‐strike Bomdila Fault beneath Arunachal Himalaya: Deformation along curved thrust traces, seismicity, and implications in hydrocarbon prospect of the Gondwana sediments

“…The Bhareli Formation consists of alternating sequence of carbonaceous shale, coal, silt stone, and sandstone in the lower part which indicates a continental facies (Figure 14). These sediments occur as thrust slices/caught up materials in folds—between the Lesser Himalayan Bomdila Group of rocks in the north and Sub–Himalayan Siwalik Group in the south (Goswami et al, 2013; Goswami, Baruah, Mahanta, Kalita, & Borah, 2020). Parts of the Permian Gondwana rocks might stay concealed beneath the orogenic belts along the periphery of the upper Assam shelf (Nayak et al, 2004; Verma & Mukhopadhyay, 1977).…”

“…(b): (19) Laskar (1956), (20) Singh (1973), (21) Singh and Mathur (1982), (22) Diener (1905), (23) Tripathi and Roy Chowdhury (1983), (24) Laul, Mishra, and Shrivastava (1988), (25) Dutta, Gill, and Srinivasan (1983), (26) Acharyya et al (1975), (27) Laskar (1954). (c) (28) Nayak et al (2009), (29) Prakash et al (1988), (30) Singh (2013), (31) Mahanta et al (2017), (32) Mahanta et al (2019), (33) Mahanta et al (2020), (34) Mahanta et al (2021), (35) Goswami et al (2013) (36) Goswami, Baruah, et al (2020), (37) GSI (2010), (38) Srivastava and Bhattacharya (1996), (39) Roy Chowdhury (1978), (d) (40) Jayprakash and Patel (1991), (41) Singh (1975), (42) Singh (1979), (43) Singh and Singh (1983), (44) Prasad, Dey, Gogoi, and Maithani (1989), (45) Sinha, Satsangi, and Mishra (1986), (46) Jayprakash et al (1990), (47) Laskar (1954), (48) Laul, Khan, and Sinha (1986), (49) Roychowdhury and Sinha (1983), (50) Sinha and Mathur (1977)…”