伸展盆地复杂断块运动学平面复原——以渤海湾盆地廊坊-固安断陷为例

本文选取廊固凹陷为例,利用平面恢复方法,研究伸展盆地断块平面运动特征.根据大兴断层的分段性,将研究区分为3个区块:西南区,中区以及东北区,又根据研究区的断块旋转特征,将中区分为中北区以及中南区.每个区块的断块运动差异性很大.通过对廊固凹陷古近系的断块进行构造平面恢复,发现其平面运动具有以下特征:西南区,断块主要以顺时针...

Map-view restoration of kinematics of complex fault-blocks in extensional basin :Insights from the Langfang-Gu'an fault-sag in Bohaiwan Gulf Basin, China

This paper uses map view restoration of Langgu fault sag to study the characteristic of the fault blocks in fault blocks in extensional basin.According to the segments of Daxing fault，the study area is divided into three zones：southwest zone，middle zone and northeast zone.According to the characteristic of fault blocks rotation，middle zone is divided into middle south zone and middle east zone.The movement of each zone is different.After the map view restoration of the fault blocks of Paleogene in Langgu sag，we have found that，the fault blocks in southwest zone mainly rotate by clockwise，and the direction of displacement is southeast to northwest； in middle zone，the fault blocks in middle south zone mainly rotate by clockwise while in middle east zone by anticlockwise，and the direction of displacement is northwest to southeast，and the displacement decreases from middle to the tips； in northeast zone，the fault blocks mainly rotate by anticlockwise except that in second member of Shahejie group，and the direction displacement is nearly south to north.The direction of displacement in southwest zone and northeast zone is nearly similar but different from that in middle east zone，which we think has relation with the segments of Daxing fault.The different rotation between middle south zone and middle east zone results from the unbalanced stress which decreases from middle to the tips.