渤海湾盆地黄骅坳陷奥陶系碳酸盐岩潜山成因分类与分布

渤海湾盆地黄骅坳陷奥陶系潜山可划分为3种类型:1)翘倾断块潜山,是在喜山期扭张运动中发育的翘倾断块,其形成与伸展作用有关,如徐黑、北大港和南大港潜山等;2)层滑冲断潜山,与寒武系内部存在的滑脱断层或盲冲断层有关,一般发育在断块的内部,燕山早期形成,如千米桥、孔西潜山以及发育在徐黑翘倾断块内部的潜山等;3)背斜潜山,可分为挤压背斜潜山和滚动背斜潜山,前者是在燕山早期扭压过程中形成的挤压背斜潜山如乌马营潜山,后者是在沧东断层伸展中上盘发育的滚动背斜潜山如孔店、王官屯潜山等。翘倾断块潜山位于黄骅坳陷的东南侧和西北侧,与埕西断层和沧东断层的伸展活动有关;背斜潜山自北向南依次分布于中南区的孔店、军马站、王官屯和乌马营以及东光潜山等;层滑冲断潜山主要发育在翘倾断块内部,黄骅坳陷中南区的层滑冲断方向从东南指向西北,而北区的层滑冲断方向则从西北指向东南,呈左行扭压态势。

Genetic classification and distribution of Ordovician carbonate buried-hills in Huanghua depression, Bohai Bay basin

Three types of Ordovician carbonate buried-hills can be identified in Huanghua depression,Bohai Bay basin.(1)Tilting fault-block buried-hills were developed during Himalayan transtensional movement and their forma- tion was related with extension faulting,such as Xuhei,North Dagang and South Dagang buried-hills.(2)Bedding slip and thrust buried-hills were generally developed within fauh-blocks during the early Yanshanian and were related with the detachment faults and blind thrust faults within the Cambrian strata,such as Qianmiqiao and Kongxi buried- hills,as well as those developed within the Xuhei tilting fault-block.(3)Anticline buried-hills can be further divid- ed into compressional anticline buried-hills and rollover anticline buried-hills,the former were formed during the transpression movement in early Yanshanian,such as Wumaying buried-hill,while the latter were developed in the hanging wall during the extension of Cangdong fault,such as Kongdian and Wangguantun buried-hills.The tilting fault-block buried-hills are distributed in the southeastern and northwestern parts of Huanghua depression,and are re- lated to the extensional movements of Chengxi and Cangdong faults.The anticline buried-hills are distributed succes- sively from north to south,including Kongdian,Junmazhan,Wangguantun and Wumaying,as well as Dongguang buried hills in south-central Huanghua depression.The detachment thrust buried-hills are mainly distributed within the tilting fault-blocks.The detachment thrusts are directed from SE to NW in south-central Huanghua depression, while those in the north are directed from NW to SE in sinistral transpression state.