反射地震剖面揭示容城凸起基岩面和断裂结构及其对地热成因的启示OACSTPCD

The Rongcheng uplift in North China boasts abundant geothermal resources.Research indicates that the Rongcheng uplift exhibits significantly different physical properties between the bedrock surface and the overlying Cenozoic strata.Moreover,the bedrock surface serves as the primary top boundary of the geothermal reservoir in the Wumishan Formation.Investigating the fine-scale struc-tures,burial depths,and faults of the bedrock surface in the Rongcheng uplift holds critical significance for understanding the distribu-tion and enrichment of geothermal resources in the area and guiding their exploration and production.Through elaborative processing of the north-south reflection seismic profile data of the Rongcheng uplift,collected by the Chinese Academy of Geological Sciences in 2018,this study obtained the high-precision geometric structure of the Rongcheng uplift within a depth of 4 km.The geometric struc-ture was calibrated using geothermal borehole data before interpretation.Key findings are as follows:(1)The Cenozoic sedimentary strata overlying the bedrock surface of the Rongcheng uplift exhibit a nearly horizontal layered distribution,serving as cap rocks of the Rongcheng geothermal field;(2)The bedrock surface of the Rongcheng uplift manifests burial depths ranging from 700 to 3 000 m,with gentle changes in the central portion,and rapidly deepening to around 3 000 m towards the periphery;(3)The Niunan and Rong-dong faults converge in the deep part,constituting a fault system along with other medium and small faults,thus facilitating the conduc-tion of water and heat;(4)The geometric structure of the Rongcheng uplift on the bedrock surface contributes to the convergence of heat flow beneath the uplift.