Thermal structure of lithosphere in Central Asian and Pacific belts and their adjacent cratons, from data of geoscience transects
P.Yu. Gornov, M.V. Goroshko, Yu.F. Malyshev, V.Ya. Podgornyi
Kosygin Institute of Tectonics and Geophysics, Far Eastern Branch of the RAS, 65 ul. Kim Yu Chena, Khabarovsk, 680000, Russia
Keywords: thermal structure; radioactive elements; models of lithosphere; heat flow; cratons; orogens; East Asia
Pages: 477-492
Abstract
We investigate the 2D thermal structure of lithosphere in the Central Asian and Pacific tectonic belts and adjacent cratonic areas of Siberia and North China using a synthesis of geothermal data from six geoscience transects covered by seismic, resistivity, and gravity surveys. The patterns of rock density, radiogenic heat production derived from U and Th abundances, thermal conductivity, temperatures, and respective heat flows reveal a layered structure. The model with layers distinguished according to density and thermal parameters includes well pronounced dome-shaped features in the crust which correlate with upwarps of the asthenospheric top. The domes are marked by high heat flows of 60-90 mW/m2 with a mantle component higher than the crustal one (30-60 mW/m2 against 20-30 mW/m2) and temperatures as high as 800-1100 °C at the Moho. Many of these features correspond to known and potential petroleum basins.
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