Deep continental studies (DCS) in India have a deep rooted traditional foundation illustrated by one of the earliest scientific documentation of lithospheric characteristics enshrined in the absolute gravity measurements in 1865, that strengthened the then emerging concepts of isostasy. However organised DCS programmes by the Department of Science and Technology (DST) started as a part of the HIMALAYAN SEISMICITY PROGRAMME in 1981, almost coinciding with the launching of the CRUMANSONATA project of the Geological Survey of India, reflecting the national awareness for the need to channelise researches in a systematic manner. Deep Continental Studies programmes were later placed under a sub-committee and then in the ambience of a separate Project Advisory and Monitoring Committee (PAMC) in 1985.The DST is playing a pro-active role in bringing together several research organizations and scientists whose researches are overviewed by the PAMC.

We are backed in our current efforts to understand the deep continental structure by fairly well documented large scale geological maps; a deep insight into the gravity field of the Indian lithosphere; and a first order estimate of the velocity structure of fairly high resolution established along some 21 DSS profiles, including ONE across the Himalaya and the rest across the Indian shield. Interpretation of teleseismic data, collected through several nationally built seismological stations, using both body and surface waves have further enhanced our knowledge of the velocity structure of lithosphere, on the one hand and the seismic response of different parts to the varying patterns of stress build up on the other. Seismic tomography has established deep continental roots deep down to >300 km in South Indian Shield and is being extended into other parts of the Indian lithosphere. Magnetovariational studies deploying large-scale magnetometer arrays in various parts of the Indian shield have mapped number of first order conductive structures, their collation with intense zones of seismicity bring out the role of fluid dynamics in reactivating sesimogenic structures. A wealth of aero-magnetic data awaits interpretation of deep structure of the magnetic crust and have been partly interpreted. MAGSAT data have also been processed and interpreted in terms of geology of the Indian lithosphere. Palaeomagnetic and magnetostratigraphic studies have been taken up in critical areas covering both volcanic provinces and sedimentary basins. AMS studies are being taken up in some select Precambrian terrains. Another important area of research supported by the DST is in the field of High Pressure-Temperature Experiments, facilities are set up at the National Centre for Experimental Mineralogy and Petrology, University of Allahabad, Allahabad.

A major progress in the implementation of Deep Continental Studies in the last decade or so is in the channelising of researches along selected transect corridors ensuring multi-institutional-multi-disciplinary approaches, following guidelines by the International Lithospheric Programme Co-ordinating Committee. Three major transects have been completed and include the JHALAWAR- NAGAUR TRANSECT CORRIDOR – 400KM long across NW Indian Shield; the MUNGWANI- KATANGI-KALIMATI TRANSECT CORRIDOR – 155 km long across Central Indian Shield and the KUPPAM-PALANI TRANSECT CORRIDOR – 300km long across the SOUTH INDIAN SHIELD. Controlled seismic experiments have been combined with potential field studies and magneto-telluric experiments along the transects. The results are integrated with geological, geochemical and geochronological data already known or generated along the transects. In the NW Himalaya, a transect - the HIMPROBE, has been launched where in addition to geological and geochemical investigations, geophysical inputs including potential fields and magneto-telluric experiments have been accomplished. Seismic profiles may be organized after the current researches show some progress that may then help to optimise the seismic inputs. A similar approach is projected along the RAICHUR-GOA SUB-TRANSECT in southern India. Expertise for the implimentation of these programmes has been drawn from different participating institutions.

Other research programmes being promoted by the DST address the thermal structure; the petrology of mantle xenoliths in alkaline dykes of widely different ages; crustal deformation studies using GPS-aided geodetic techniques and geochronological constraints on lithospheric evolution. A well-equipped national facility for geochronology and isotope geology is being set up in the University of Roorkee, Roorkee with the establishment of a thermal ionization mass spectrometer laboratory.