Research Projects

Deciphering the processes involved in the genesis and evolution of transcrustal large silicic magmatic systems is currently a topic of global interest. Earlier theory that a large magma-filled chamber acted as magma supplier to volcanoes or batholiths (eruptible and non-eruptible, as the case is), is though widely acclaimed for the last 100 years, now under intense scrutiny. Several geophysical studies have argued for transcrustal magmatic systems (TCMS: magma reservoir), an inter-connected network of magmas(chambers) of varying sizes occurring at different crustal depths in which magma may variably be with ‘crystal mush’(e.g., Bachmann and Bergantz, 2008; Farrell et al., 2014; White and McCausland, 2016; Sparks et al., 2019). In the volcanic and to some context in plutonic settings (e.g., Barnes and Werts, 2022), the concept of silica to intermediate magma reservoir is increasingly being tested in order to understand crustal growth and evolution, magma differentiation and the underlying crust-mantle interactions better. Why some TCMS lead to eruptions (volcanic setting), and others do not (plutonic setting) is therefore becoming a major theme in contemporary magma reservoir studies. In Indian context, occurrences of LIP rhyolites and large granitoid thus offer an opportunity to study this aspect with renewed effort using new field, geochemical and mineralogical data and constraints, to build plausible petrological models. Given that, two geological provinces- one plutonic, and the other volcanic- of similar age at the NeoArchaen-Palaeoproterzoic transition believed to be a major crust building time- the ~2.6-2.1 Ga Bundelkhand granitoid and associated Quartz reef rocks and the ~2.5 Ga Dongargarh LIP rhyolites (Bijli Rhyolites in Bastar craton) are identified for this study. This work shall encompass detailed field survey in parts of Bundelkhand and Bastar, thin section studies to unravel petrographic/micro structural record. Geochemical studies will include XRF, EPMA-CL and FE-SEM-CL, LA-ICPMS, ICP-MS, TEM, Oxygen isotopic studies and Raman Spectroscopy for selected samples. The project expects to add new knowledge / help clarify existing ideas of large silicic magmatic systems, both in volcanic and plutonic settings. Trained manpower development in this frontier area of research is also a major goal of this endeavour.