Paleostress Field Reconstruction from the strike-slip faults of Neoarchean Closepet Granite (Eastern Dharwar Craton, South India): Its implications in understanding Precambrian Tectonics

Granite emplacement is often assisted by shear zones. These shear zones may be synmagmatic and can lead to the development of various structural features, ranging from complex fabric to faults and their interactive networks. The Neoarchean Closepet Granite (2.56-2.51 Ga) of Eastern Dharwar Craton, India is replete with faults and fractures of various orientations, which are used to decipher the regional brittle tectonics. Detailed analysis of strike-slip and high-angle oblique-slip faults using the Right Dihedron and Rotational Optimization methods reveals an overall E–W oriented horizontal regional compressive stress. The area is further subdivided into smaller domains to observe variations in the local stress field. Results indicate a distinct deformation pattern across the region. The northern portion is influenced by ENE-WSW directed regional compression, while the southern portion is shaped by ESE-WNW directed regional compression. Fault orientations and their kinematics across the pluton indicate that the faults are associated with a large-scale Riedel shear along the pluton boundary. In the north, deformation is compatible with an NW-SE sinistral shear zone, while in the south, fault patterns are consistent with an NNE-SSW dextral shear zone. This variation in shear is attributed to the overall geometry of the pluton boundary. We also interpret that, during the emplacement and the post-emplacement period, the rheological boundary between the granite and the surrounding host rock, evolved into a shear zone, facilitating the development of faults across the Closepet pluton.