Modelling Paleogeotherms in the Continental Lithosphere: A Brief Review and Applications to Problems in the Indian Subcontinent
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In this work, we have reviewed the fundamental aspects of heat transfer theory that underlie the modelling of steady state and transient paleogeotherms in the continental lithosphere. We reviewed different types of models of paleogeotherms involving one or two layers, a combination of rheological and thermal boundary layers, and the stagnant-lid convection model in which convection is allowed in the lower part of a thermal boundary layer. We also reviewed the studies on the calculation of steady state paleogeotherm in the Dharwar cratons during the Proterozoic period that have been constrained by the heat flow data and the inferred P-T conditions of the mantle xenoliths in the Proterozoic kimberlite pipes. Several transient thermal models have also been discussed. These include the transient effects of CO2 fluxing from the mantle, crustal melting and melt focusing, and overthrusting. For the latter we considered both single and double thrust sheets derived from the same and different places. An interesting conclusion that emerges from this study is that a metamorphic field profile (MFP), which defines the locus of temperature maxima experienced by exhuming parcels of rocks in response to erosion, is not significantly affected by the different thrusting scenarios.
KeywordsThermal Boundary Layer Mantle Xenolith Thrust Sheet Dharwar Craton Kimberlite Pipe
RNS is grateful to Indian National Science Academy, New Delhi, for award of a Senior Scientist position.
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