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 formation 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 buriedhills

as well as those developed within the Xuhei tilting fault-block.(3)Anticline buried-hills can be further divided 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 related to the extensional movements of Chengxi and Cangdong faults.The anticline buried-hills are distributed successively 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.