Growth of the Greater Indian Landmass and its assembly in Rodinia: Geochronological evidence from the Central Indian Tectonic Zone

The geological evolution of the Gangpur Schist Belt, eastern India: Constraints on the formation of the Greater Indian Landmass in the Proterozoic

“…This event is synchronous with the M 2B and M 1G metamorphism respectively of the Upper Bonai and Gangpur Groups, and the emplacement of pegmatitic granites in the Upper Bonai Group. The Grenvillian metamorphism of the Gangpur Group of rocks can be correlated with continent–continent collision and granulite facies metamorphism of the rocks of Sausar mobile belt at 1.0 Ga (Bhowmik et al., ) and with transpressional tectonics during oblique collision along the Tan–Gavilgarh Shear Zone at 1.1 Ga (Chattopadhyay & Khasdeo, ). The CGC also underwent a pervasive Grenville‐age high‐grade metamorphism accompanied by regional deformation and granite magmatism (Acharyya, ; Chatterjee et al., ; Maji et al., ; Rekha et al., ; Sanyal & Sengupta, ; Sanyal et al., ).…”

“…(, ) argued that the final amalgamation of the Northern and Southern Indian Blocks took place during Grenville‐age orogeny along the CITZ and that proto‐India was not a single coherent block at the time of its incorporation within Rodinia. However, the gamut of available geochronological data shows that major crustal domains of both the Northern and Southern Indian Blocks such as the Eastern Ghats Belt, the Cauvery Shear Zone system, and the Madurai Block in the northern Southern Granulite Terrane, the Aravalli–Delhi Mobile Belt, the Malyagiri Supracrustal Belt at the southern margin of the Singhbhum Craton, the Sausar Mobile Belt, the GSB, the North Singhbhum Mobile Belt, the CGC, and the Shillong–Meghalaya plateau of the CITZ as well as crustal units in East Antarctica (e.g., Rayner Complex) underwent early Neoproterozoic orogenesis (Aftalion, Bowes, Dash, & Dempster, ; Bhowmik et al., , ; Bose, Dunkley, Dasgupta, Das, & Arima, ; Braun & Appel, ; Braun, Cenki‐Tok, Paquette, & Tiepolo, ; Buick et al., ; Chatterjee et al., , ; Chatterjee & Ghosh, 2011; Chattopadhyay et al., ; Dasgupta & Sengupta, ; Grew & Manton, ; Karmakar et al., ; Kooijman, Upadhyay, Mezger, Raith, & Berndt, ; Li et al., ; Mezger & Cosca, ; Mukherjee et al., ; Paul et al., ; Rekha et al., ; Santosh & Drury, ; Santosh, Yokoyama, Biju‐Sekhar, & Rogers, ; Sanyal & Sengupta, ; Sarkar & Paul, ; Shaw et al., ; Simmat & Raith, ; Upadhyay & Raith, ; Upadhyay, Raith, Mezger, Bhattacharya, & Kinny, ; Upadhyay, Raith, Mezger, & Hammerschmidt, ), implying that these crustal units were sutured together as a coherent block by c . 1.0 Ga. Taken together, this supports the idea that India–Antarctica–Australia probably formed a coherent land mass as a part of the Rodinia supercontinent.…”

“…The granulites occur as rafts, pods, and lenses within intensely tectonized felsic gneisses/composite gneisses (Acharyya & Roy, ; Bhowmik, Pal, Roy, & Pant, ; Bhowmik & Roy, ; Bhowmik et al., ; Roy & Prasad, ; Roy et al., ). The CITZ has a complex and protracted geological history involving Palaeoproterozoic subduction‐metamorphism and granite emplacement at 1.8–1.7 Ga (Deshmukh, Prabhakar, Bhattacharya, & Madhavan, ), granitoid magmatism at 1.60 Ga (Bhowmik, Wilde, & Bhandari, ; Bora, Kumar, Yi, Kim, & Lee, ), granulite facies metamorphism at 1.62–1.42 Ga (Bhandari, Pant, Bhowmik, & Goswami, ), and upper amphibolite to granulite/high‐ P granulite facies metamorphism at 1.06–0.94 Ga (Bhowmik, Wilde, Bhandari, Pal, & Pant, ; Chattopadhyay et al., ). At its eastern extremity, the CITZ separates into three thrust belts that divide the orogen into the Gangpur Schist Belt (GSB), the North Singhbhum Mobile Belt, and the Chhotanagpur Gneiss Complex (CGC).…”

“…1.1 Ga. Bhowmik et al. (, ) suggested that the earliest amalgamation event in the CITZ occurred between 1.60 and 1.42 Ga, forming an accretionary orogen. This was followed by continent–continent collisional orogeny between 1.06 and 0.94 Ga leading to the suturing of the Northern Indian Block and the Southern Indian Block.…”

Evolving provenance in the Proterozoic Pranhita-Godavari Basin, India

“…Work over the last decade has established that different Pur ana basins opened at different times, but the upper age limits of major depositional sequences are largely unconstrained, impeding the evaluation of their global significance. The question of the upper age limit of Pur ana sequences, and the possibility of their continuity into the late Neoproterozoic or into the Cambrian has been debated for a long time, though recently, U-Pb ages from tuffs sampled from the Chhattisgarh and Indravati basins has led to a new hypothesis suggesting closure of at least these Pur ana basins at c. 1000 Ma (Bickford et al, 2011a;Mukherjee et al, 2012), coinciding with orogenesis in the Eastern Ghats (Korhonen et al, 2011) and the central Indian tectonic zone (Bhowmik et al, 2012). …”