佳伊断裂带晚白垩世走滑-逆冲事件的新证据

摘要

A series of strike-slip thrust faults were found in Yehe of Siping,exhibiting features of flat and steep-dipping fault planes with strikes ranging from NNE15°～35° and distributing in an echelon pattern.These faults form the branch faults between the two major boundary faults of Jiamusi--Yitong.The branch faults intersect the major faults with striking of NE 45° at an acute angle,indicating that the boundary faults have a dextral strip slip characteristic.The discovery of the strike-slip thrust fault zone in Yehe provides a new evidence for the strike-slip thrust event during late-end Late Cretaceous in the Jiamusi--Yitong fault.Yehe branch fault zone is the southern extension of the Shiling branch fault zone.Intersecting same strata,possessing identical structural characteristic and tectonic attribute and belonging to one strike-slip thrust system,the two fault zones are produced in the same geodynamic background in the late-end Late Cretaceous.%在四平市叶赫镇发现一系列走滑-逆冲断层,断层面平直、陡倾,走向集中在NNE15°～35°范围内,组成了佳木斯-伊通两条主干边界断裂之间的分支断裂带,分支断裂呈雁列式排布,与走向NE45°的主干边界断裂呈锐角相交,指示边界断裂具有右旋走滑特征.叶赫镇走滑-逆冲断裂带的发现为佳木斯-伊通断裂存在晚白垩世晚期-末期的走滑-逆冲事件提供了新证据.叶赫镇分支断裂带是石岭镇分支断裂带向南部的延伸,两者切割了相同的地层,具有相同的构造特征和构造属性,属于同一走滑-逆冲断裂系统,它们是晚白垩世晚期-末期同一地球动力学背景下的产物.