Thermophysical parameters and lithospheric thermal structure in Guide Basin, Northeast Qinghai-Tibet Plateau

摘要

Comprehensive knowledge in lithospheric thermal structure and subsurface temperature distribution is indispensable for the research and utilization of geothermal resources. This paper studies the characteristics of heat generation rate and heat conductivity of shallow rocks and deep rocks encompassing Guide Basin by sampling, measuring, data collection and analysis, establishes the conceptual model of its lithospheric thermal structure. The research shows that the mantle heat flow of Guide Basin is about 35 mW/m(2), and the ratio of crust heat flow to mantle heat flow is 1.2. With the one-dimensional steady-state thermal conduction formula, the temperature at different depth is calculated in the research area. Ground temperature at the depth of 1.5 and 3 km is about 72 and 115 degrees C, respectively. The depth of Curie surface is about 21-22.5 km with the temperature of 570-600 degrees C, and the temperature of Moho is about 1100 degrees C. Most of the analysis results above are consistent with previous research findings in the research area and its vicinities, proving the reasonability of the lithospheric thermal structure model established by this paper. As the geothermal research of Guide Basin still stays at a low level, the conceptual model of lithospheric thermal structure in Guide Basin established in this paper still needs to be improved and corrected with new methods and data in further study.