Petrography and Mineral Chemistry of the Granitoids in the Eastern Part of Central India, Central Indian Tectonic Zone (CITZ)

The NE-SW trending Central Indian Tectonic Zone (CITZ) is a prominent suture zone that was brought out by the amalgamation of the Northern Indian Block (NIB), constituted by the Aravalli-Bundelkhand craton in the north and Southern Indian Block (SIB), constituted by the Bastar-Singhbhum and Dharwar cratons to the south. The CITZ is traversed by major tectonic lineaments parallel to its length: the Son-Narmada North Fault (SNNF), the Son-Narmada South Fault (SNSF), the Gavilgarh-Tan Shear Zone (GTSZ), and the Central Indian Suture/Shear (CIS) from north to south. The study area located in the eastern part of Central India, near the GTSZ records different phases of granite intrusions. They are comprised mainly of two types of granite facies: coarse to medium-grained pink granite and medium to fine-grained gray granite. Pink granite are composed by K-feldspar, plagioclase, biotite with accessory hornblende, apatite, zircon, titanium-magnetite and garnet with rare muscovite, chlorite; whereas the gray granite is more enriched in ferromagnesian phases. Mineral chemistry data sets are used to constrain the physicochemical, pressure–temperature condition of magmatic origin and depth of emplacement of studied granite. Previous results from the study area were not subjected to the genesis and tectonic setting of these granites. Biotite composition with low MgO content (5.05–5.59) and high FeO (23.66–24.60) suggests iron enrichment, and the narrow range of the Fe2+/Fe2+ + Mg suggests their magmatic nature. The 10*TiO2–(FeOt + MgO)–MgO ternary diagram is used to determine the nature of biotite, where primary biotite is most likely affected by post-magmatic fluids. In the ternary diagram of FeOt–MgO–Al2O3, biotite compositions suggested that these granitic rocks are S-type with peraluminous characteristics and originated by syn-collisional tectonic setting. The ferromagnesian minerals of biotites composition fall in the Fe-rich siderophyllite field in the ternary plot (Alvı + Fe3+ + Ti)–Mg–(Fe2+ + Mn) and the FeOt/(FeOt + MgO) versus MgO (wt.%) correlation plot indicates a crustal source. The Ti content in biotite thermometry suggests crystallization at 716–730 °C at 4.24 to 5.57 kbar pressure. The biotites characteristics suggest the magma that initially derived from metasomatized crust through melting in plate interiors.