The geothermal regime and geodynamic mechanism of the Mongolia-Baikal rift zone
Huang Fang1, He Lijuan2, Wu Qingju1
1. Division of Physics of the Earth's Interior and Seismotectonics, Institute of Geophysics, China Earthquake Administration, Beijing 100081;
2. State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029
The geodynamic mechanism of the formation and evolution of Mongolia-Baikal rift zone has always been the focus of argument. So far, the research related to the geothermics has always been comparatively absent in the area. Based on the predecessors' study on the unique geomorphology, structures and basaltic volcanism, combined with the geothermal study of the Mongolian-Baikal area, its geodynamic mechanism was discussed. According to the latest updated heat flow data from the global heat flow database of the international heat flow commission(IHFC), we analyzed the latest heat flow in the area. In the Mongolia area, the heat flow of the Hovsgol rift and its adjacent rifts in the northern Hangay dome is highest, more than 120 mW/m2; The heat flow of overall Baikal rift is high. The highest value in the northest Baikal is more than 160 mW/m2(higher than the previous reports); The heat flow in its central part is higher (～120 mW/m2). Based on the latest data of heat flow and the existing research results, the paper tends to accept a Late Cenozoic mantle plume model as the geodynamic mechanism of the formation of the Mongolian-Baikal area.