沉积速率对渤中坳陷大地热流的影响

盆地内快速剧烈的构造作用可导致热异常，在利用盆地热历史揭示深部动力学过程时，需消除热异常的影响. 本文根据瞬时热传导原理，校正了渤海湾盆地渤中坳陷低热异常，准确地约束了盆地深部动力学状态. 对渤中坳陷内3口典型井进行热流校正结果表明，渤中坳陷古近纪以来快速沉积导致其现今（~60.9 mW·m^-2）未达到热平衡（低热异常）. 校正后的热流值平均约为67.4 mW·m^-2，比现今高5~10 mW·m^-2. 利用校正后的热流值计算得到的渤中坳陷的“热”岩石圈的平均厚度约为70 km，比修正前的厚度（82~100 km）减少了13~28 km.

Effect of deposition rate on geothermal field in Bozhong depression,Bohai Bay Basin

Thermal anomalies can be caused by fast and intensive tectonism in sedimentary basins. And the thermal anomalies should be eliminated when the thermal history is used to provide continuous information on time and space for the geodynamic process at depths. In this paper, based on the dynamic-instantaneous heat conduction theory in solid, geothermal correction of 3 typical wells in Bozhong depression has been modeled. The results indicate that the rapid subsidence in Bozhong depression which started at Paleogene leads to the present geothermal disequilibrium. The average heat flow at present is about 60.9 mW·m^-2, a higher heat flow 67.4 mW·m^-2 can be obtained when the geothermal field is on the condition of geothermal equilibrium. The average thermal lithosphere thickness in Bozhong depression is about 70 km, calculated by using the corrected heat flow, which is 13~28 km thinner than before (82~100 km). The result is consistent with the lithosphere thickness obtained from geophysics and xenoliths.