Deep crustal studies



The programme aims to achieve a comprehensive understanding of the deep crustal structure underneath Indian continental margins with special emphasis on the onshore-offshore structural linkages. The evolutionary history of our margins in the Arabian Sea and Bay of Bengal sectors would be deciphered using comprehensive marine geophysical/geological data collected from onshore as well as offshore areas. Considering the extent of the Indian continental margin, a phased approach starting from the south-west Indian margin would be initiated to addresses the following key questions:


Understanding the structure and evolution of the Southwest Indian Margin (SWIM) and its interior:


Lithospheric rifting of is a fundamental process in the growth and evolution of continents, and it is one that has substantial societal relevance by virtue of the global hydrocarbon reserves accumulated within basins formed through rifting. Rifting proceeds from the application of extensional stress to the accumulation and localization of strain until the lithosphere ruptures, whereupon seafloor spreading and production of oceanic lithosphere accommodate most extension. Continental breakup thus constitutes a dramatic expression of two fundamental geological processes: deformation and magmatism. Yet first-order questions exist about every process in the rift-to-drift sequence. We lack a full understanding of both the magnitude and cause of the stresses that drive rifting, the deformational mechanisms by which continental lithosphere responds to those stresses, and the key parameters that control this deformation. Similarly, the role of the rift-related magmas in localizing strain and advecting heat from asthenosphere to lithosphere is poorly understood, as are the controls on mantle melting during extension (e.g., mantle temperature, volatile content, and small-scale convection). Understanding these processes is one of the fundamental goals of earth scientists today. The salient expected outcomes of this project are enumerated below:


a) Imaging of basement and Moho across the SWIM
b) Nature of crust in the Laccadive basin area
c) The link between Laccadive and Laxmi Ridges?
d) Offshore extension of onshore tectonic elements and vice versa?
e) Mapping of small-scale sedimentary structures within the shelf region