indo–us workshop on “intraplate seismicity” - The CERI Blog

that the thermal perturbations associated with the ~65 Ma -­‐ old Deccan volcanic episode
were localized and the transients have decayed. In contrast, the Archaean to Proterozoic
segments in the northern and eastern parts of the shield show heat flux consistently higher
than 50 mW m −2 : 59–63 mW m −2 along the Singbhum Thrust Zone (in Singbhum craton), 51–
62 mW m −2 in the Bastar craton, and 56–96 mW m −2 in the Aravalli Province. The Gondwana
basins have a generally high but variable heat flow in the range 46–107 mW m −2 . While the
Damodar Valley basins reveal a narrow range (69–79 mW m −2 ) in heat flow, the other basins
show large variability. The Tertiary Cambay basin shows higher heat flow, 75–96 mW m −2 in
the northern than in the southern parts, 55–67 mW m −2 . On the basis of heat flux
distribution, available datasets for thermal conductivity and radiogenic heat production of
crustal rocks, constraints from upper mantle seismic shear wave velocities and xenolith
geothermobarometry (Roy and Mareschal, 2011), temperature computations indicate that
the entire upper-­‐ to-­‐ middle crust in the Indian SCR could be a region of instability. However,
the great majority of M>5 earthquakes have occurred in the shallow (