Discuss on tectonic and sedimentary evolutions of Bohaiwan basin——taking Jiyang sag as an example

Studies on the strata and tectonic characters suggest that the tectonic and sedimentary evolutions in Bohaiwan ba- sin are closely related to Danlu fracture zone.which recorded several tectonic movements including the sinistral and the dextral types.The basin has been undergone such relatively intense movements such as Indosinian movement,Yanshan movement and Himalayas movement,during which the com- pressive fold is the main tectonic feature in the Iindosinian movement;the sinistral sheer strike-slip happened inⅠandⅡepisodes of Yanshan movement,and the dextral sheer strike-slip arose inⅢepisode of Yanshan movement;and the sinistral sheer strike-slip and the pull-apart block faulting appeared in the Himalayas movement.It is conclu- ded that the tectonic framework generated in early Cenozoic era is subject to Indosinian movement and Yanshan move- ment with an apparent succession,and the swells or depres- sions were reconstructed by faults on the basis of folds with- in the basin.