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

Abstract

Structural mapping and fieldwork in the Lesser and Higher Himalayan sequences in the western Arunachal Himalaya reveal crucial deformation fabrics in the Main Central Thrust (MCT) and Dirang Thrust (DT) zones. The top‐to‐SW ductile shear in the MCT and DT zones is correlated with the swing in the trend of MCT and DT from NE to NNW. The curved MCT and DT as traced by previous authors on the regional map of Arunachal Himalaya are studied. It is found that at places where these faults swing, shear senses developed at the meso‐scale. These shear senses are studied in meso‐ and micro‐scales. Seismicity in the western Arunachal Himalaya is influenced by basement cross‐strike crustal‐scale NW‐trending buried Bomdila Fault (BF). Landslides occur frequently along the Bhalukpong‐Bomdila–Sela traverse are also linked with the transverse BF. In its southern part, the BF coincides with the Dhansiri Lineament and is the basin margin fault in the upper Assam shelf. The Gondwana sediments extended further south below the Brahmaputra alluvium along the fault is to be explored for hydrocarbon exploration.

Introduction, Part 2—Geodynamic evolution of Eastern Himalaya and Indo‐Myanmar orogenic belts: Advances through interdisciplinary studies

“…Goswami, Kalita, et al (2022) lucidly discussed the deformation kinematics in the MCT and Dirang Thrust (DT) zones through meso‐ to micro‐scale ductile to ductile‐brittle fabrics imprinted in the rocks. They highlighted the influence of the basement cross‐strike faults in the orientation of the major Himalayan thrusts, such as the MCT in Arunachal Himalaya.…”

“…Geological map of Eastern Himalaya, Indo‐Myanmar orogenic belt, northern, Central Myanmar, and adjacent areas (modified after Mitchell et al, 2007; Searle et al, 2007; Y. R. Singh, Singh, Singh, et al, 2022). Locations of study area presented in the issue include 1/S2: Kundu and Hazarika (2022); 2/S2: Y. R. Singh, Singh, Singh, et al (2022); 3/S2: Rawat and Luirei (2022); 4/S2: Kayal et al (2022); 5/S2: Choudhury et al (2022); 6/S2: N. M. Sharma et al (2022); 7/S2: Goswami, Gogoi, et al (2022); 8/S2: Bikramaditya et al (2022); 9/S2: Goswami, Kalita, et al (2022); 10/S2: Joshi (2022); 11/S2: Jha and Sharma (2022); 12/S2: Shukla et al (2022); 13/S2: Khonglah et al (2022); 14/S2: Ali and Duarah (2022); 15/S2: Mohanty et al (2022); 16/S2: Chanu et al (2022); 17/S2: Majumdar, Gogoi, and Ghatak (2022); Majumdar, Gogoi, Ghatak, Saikia, et al (2022); 18/S2: Ding et al (2022); 19/S2: Ghose et al (2022); 20/S2: Hussain and Dey (2022); 21/S2: Ozukum et al (2022); 22/S2: Jamir et al (2022); 23/S2: Chaubey et al (2022); 24/S2: Bora, Borah, et al (2022); Bora, Mukherjee, et al (2022); 25/S2: Khuman and Ibotombi (2022); 26/S2: Y. R. Singh, Singh, Singh, et al (2022); 27/S2: Thokchom and Kshetrimayum (2021); 28/S2: Barman et al (2022); 29/S2: V. Sharma and Biswas (2022)…”