穿地壳岩浆系统改变岩石圈流变和热结构OACSTPCD

This paper takes the transcrustal magmatic system in eastern Shandong as an example.By studying the rheological structure and thermal structure of the lithosphere,combined with the existing field exploration and geophysical data,the crus-tal evolution in eastern Shandong was reduced and explained,and the magma deep thermal effect model of the transcrustal magmatic system is further established to understand the deep dynamic evolution mechanism of the lithosphere.The geother-mal temperature of the target area is preliminarily estimated,and the lithospheric structure and the distribution of geothermal reservoirs above 6 km in eastern Shandong are predicted,and the theoretical model of the formation of deep geothermal reser-voirs in eastern Shandong is further elaborated.The results show that the North China Craton formed a stable and rigid conti-nental crust in the Archean,and the granites are mainly composed of non-metamorphic or low-metamorphic supracrustal rocks.Since the Mesozoic,the basement of the North China Craton has been unstable and experienced strong tectono-mag-matic activities,resulting in strong tectonic deformation,delamination and replacement of the lithospheric mantle.In the late Mesozoic,due to the intense deep tectonic activity in the eastern part of Shandong Province,the transcrustal magma surged up to the surface along the large fault,accompanied by the thermal uplift effect and assimilation and contamination.The thickness of the lithosphere is thinned,and the mantle rises to the upper and middle crust.With the melting of the supra-crustal rock,the incompatible radioactive elements are re-upwelled with the magma,and the heat-generating radioactive ele-ments are continuously transported to the shallow crust,thus changing the thermal structure and rheological structure of the lithosphere.