Crustal architecture beneath Madurai Block, southern India deduced from magnetotelluric studies: Implications for subduction–accretion tectonics associated with Gondwana assembly

Three‐dimensional lithospheric electrical structure of Southern Granulite Terrain, India and its tectonic implications

“…During these campaigns remote reference mode of data acquisition could not be taken up due to nonavailability of required equipment and also due to logistic problems. The 2‐D modeling results of the subsets of data presented earlier [ Harinarayana et al ., , ; Naganjaneyulu and Harinarayana , ; Naganjaneyulu and Santosh , , ; Naidu et al ., ] were thus limited to different segments of the SGT. For the present 3‐D analysis, which aims at providing a comprehensive 3‐D model for deep electrical structure for the entire SGT, we have selected the stations falling along a 500 km long N‐S traverse starting from Dharwar craton in the north to the southern edge of India near the coast.…”

“…Several geophysical studies were carried out during the last three decades in the SGT including gravity [ Subrahmanyam , ; Narain and Subrahmanyam , ; KrishnaBrahmam , ; Mishra and Rao , ; Singh et al ., ], aeromagnetics [ Reddi et al ., ], seismic tomography [ Rai et al ., , 2003], deep seismic sounding [ Reddy et al ., ], and magnetotellurics [ Harinarayana et al ., , ; Naganjaneyulu and Harinarayana , ; Naganjaneyulu and Santosh , , ; Naidu et al ., ]. Some of the geophysical responses observed in this part of the Indian plate such as the nature of teleseismic velocities, electrical structure models from MT studies, and crustal thickness variations modeled from deep seismic and gravity observations provided valuable insights into such crustal heterogeneities and structural complexities in different segments of the SGT.…”

Cryogenian (∼830Ma) mafic magmatism and metamorphism in the northern Madurai Block, southern India: A magmatic link between Sri Lanka and Madagascar?

“…This is consistent with the suggestion that the northern Madurai Block overlay a south (present direction) dipping subduction zone throughout much of the Neoproterozoic with Neoproterozoic India in the Edicaran-Cambrian. A south-dipping electrical feature beneath the southern PCSS and northern Madurai Block, has been interpreted as a relic of the pre-collisional subduction system (Naganjaneyulu and Santosh, 2011 (Tomson et al, 2006). However, it would be extremely hard to produce these basic to ultrabasic rocks from partial melting of the surrounding felsic crust.…”

Exploration and assessment of the geothermal resources in the Hammam Faraun hot spring, Sinai Peninsula, Egypt

“…Schill et al (2010) carried out a 2D magnetotelluric and 3D inversion of existing gravity data based on a 3D geological model in the area of the geothermal power plant of Soultzsous-Forêts in northeastern France. Naganjaneyulu and Santosh (2011) analyzed MT data along the N-S trending Kalugumalai-Tiruchengode profile in the Madurai Block in southern India to evaluate the crustal architecture and its implications on the tectonic development of Madurai Block. Sari and Salk (2006) estimated the thickness of the sedimentary cover on the Menderes Massif in western Turkey as deduced from 2D and 3D analyses of the gravity data.…”