CSIR-NGRI

Magnetotellurics

The Magnetotelluric (MT) group of CSIR-NGRI envisages resolving various geoscientific problems, ranging from fundamental earth dynamics and tectonic evolution to exploration of conventional as well as unconventional energy resources. This group has more than three decades of experience and MT measurements completed at more than 4000 locations in the Indian subcontinent and abroad under different projects supported by agencies such as ONGC, OIL, MNRE, MoES, DST, etc. The group is equipped with state-of-the-art MT data acquisition systems, including Controlled Source Audio MT (CSAMT), data processing, and modeling tools, including in-house/indigenously developed processing and inversion algorithms. Major ongoing research activities of the group are below.

UNCOVER A major project in understanding the lithospheric architecture of the Rajasthan region and its mineral potential is initiated with the support of the Geological Survey of India. MT and Deep Seismic Sounding methods will be employed to map the crustal and upper mantle structural features along a ~600 km long Churu-Tikamgarh transect to bring-out the minerals systems along the transect. To decipher the electrical resistivity structural changes from shallow crustal to deep lithospheric depths, Audio-MT (AMT), Broad-Band MT (BBMT), and Long-period MT data acquisitions are planned. At present MT measurements were made at 60 locations along the transect.

Geothermal assessment studies in the Ladakh union territory: MT studies are employed in different hot spring areas (Puga and Panamik) of Ladakh region to map the crustal resistivity structure and evaluate the geothermal resources under these areas, which will help in the sustainable development of the region.

Evaluation of the terrane boundary between DC and SGT through 3D MT study: A research project intended to answer the ambiguity on the suture status of Palghat Cauvery Suture Zone (PCSZ) and tectonic processes involving the amalgamation between Dharwar Craton (DC) and Southern Granulite Terrain (SGT) by imaging the 3D lithospheric resistivity structure of the western segment of PCSZ and its neighboring Coorg Block is taken up with the support of MoES, Govt. of India.

DEEP SEATED MINERAL PROGNOSIS BY GEOPHYSICAL TECHNIQUES: LITHOSPHERIC STRUCTURE AND RELATIONSHIP WITH KIMBERLITE CLUSTERS OF KALYANDURG-TIMMASAMUDRAM-CHIGICHERLA (KTC), ANANTAPUR DISTRICT, ANDHRA PRADESH: In order to understand the genesis of diamondiferous and non-diamondiferous kimberlite genesis in the Eastern Dharwar Craton (EDC) MT surveys were made along one long and two short profiles covering the KTC kimberlite cluster and schist belts.

Electric structure of NW Himalaya: The electrical structure of the crust and upper mantle beneath the NW Indian Himalaya is investigated along multiple profiles that cut across the various litho-tectonic units of NW Himalaya. The study aims to give insight into the relation between the structural features and seismogenesis in the region, and the results would help in the seismic hazard assessment of the area.