Heat Flow of Central Asia

Abstract

Revisions have been made to the geothermal data in Central Asia. These data concern the south Siberian platform (64 boreholes, average flow of 38±4 mW/m2), the Baikal rift zone (72 boreholes, average flow of 71±21 mW/m2), the Trans-Baikal area with a moderate rate of mountain formation (57 boreholes, average flow of 51±5 mW/m2), Mongolia (32 boreholes, heat flow varying from 40 – 64 mW/m2), and China (about 300 boreholes).
Heat flows in continental East China, which includes four Cenozoic rifts that belong to the western or eastern rift systems, vary from 26 to 106 mW/m2, with a mean value of 61±2 mW/m2. The rifts are generally hotter (average flow of 68-70 mW/m2) than their surroundings (average flow of 49-56 mW/m2). Especially deep flow over 80-100 mW/m2 is associated with rift basins and active faults.
Maps of geothermal activity, heat flow, and crustal thickness have been constructed for southeastern Siberia, Mongolia and East China. Correlations have been found between rifting, current geothermal activity, and deep structures of major tectonic units in China.