Geological and Geophysical Studies over the Deccan Traps (GGDT)
Chief Co-ordinator - Dr. Gautam Gupta & Members
The Deccan Volcanic Province (DVP) represents one of the largest Continental Flood Basalt (CFB) provinces in the world, covering an area of 500,000 km2, which records vast accumulation of basalt in a relatively short time span entailing the Cretaceous/Tertiary boundary (KTB). The enormous eruption of these basalts ~65 Ma ago, is attributed to the interaction of the Reunion plume with the overlying Indian lithospheric plate during its northward flight after breakup from the Gondwanaland. It has been argued that the voluminous Deccan lavas erupted very rapidly in a rather short interval of less than a year at the KTB leading to several biological and geological anomalies at the KTB. Hence it is of immense importance to obtain the precise age and duration of Deccan volcanism. The thick lava flows have blanketed the underlying crust due to which the geology and tectonics of sub-basalt remains speculative, both in terms of resources as well as hazards assessment. There are several hot water springs distributed along north-south and east-west belt within the DVP. However, the source of the geothermal energy of these springs, the environmental impact of the geothermal sources etc. are not well understood. Network of lineaments/faults in the surface and sub-surface within the DVP may be accumulating stress and can release energy at point of time. Recent example of such a tectonic activity has been the earthquake swarm in the Mumbai suburban region close to Palghar, where starting from November 2018 several thousands of earthquakes (longest in the history of non-volcanic swarm)in micro to minor range magnitude have been measured by National Centre for Seismology. Reservoir induced seismicity associated with Koyna dam is well studied. Hence it is important to understand the crustal deformation which is undergoing in the DVP. The Quaternary deposits occurring in the fluvial, lake, glacial and marine environment are potential archives for delineating the palaeoclimatic changes using Environmental magnetic methods. However, Quaternary sediments and soil occurring in the DVP have also remained uninvestigated so far, which are potential archives for delineating past neo-tectonic and Late Quaternary evolutionary history. Saltwater intrusion into the coastal aquifer has long been recognized as a major concern around the world. The intrusion occurs as a result of the induced flow of seawater into freshwater aquifers originally caused by groundwater development around the coast.Groundwater resources along the west coast of Maharashtra are vulnerable to saline water ingress and thereby contaminating the coastal freshwater aquifers. Hence it is of paramount importance to map the saline water ingress into the land areas and also to understand the quality of water as the water is used for drinking, irrigation etc. Thus DVP, is still engrossed with a plethora of scientific questions which need to be addressed, although a variety of scientific experiments have been conducted till date.
Under this program, using a variety of geophysical tools,it is proposed to study the palaeo-climate, effects of weathering and diagenesis during and after sediment deposition, magmatism, structure, tectonics, evolution, saline water ingress, aquifer mapping and water quality studies along the coastal areas, hydrological behaviour of aquifer system in the hard rock terrain, crustal deformation and along the coastal areas with microseismic activity and geophysical and geochemical characterization of geothermal springs.