柴达木盆地北缘晚海西—印支期古构造应力分析  

An Analysis of Late Hercynian–Indosinian Paleotectonic Stress on the Northern Margin of the Qaidam Basin

作　　者：彭渊[1] 马寅生[1] 刘成林[1] 孙娇鹏 程海艳[1] 代昆[3] 郑策[3] 

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]中国石油大学(华东)地球科学与技术学院,山东青岛266555 [3]中国石油大学(北京)地球科学学院,北京102249

出　　处：《地球学报》2015年第1期51-59,共9页Acta Geoscientica Sinica

基　　金：中国地质调查局地质调查项目"柴达木盆地油气资源潜力评价"(编号:1212010818054)和"柴达木盆地古生代油气资源调查评价"(编号:1212011120964)联合资助

摘　　要：为了更好认识柴北缘晚海西—印支期古构造应力特征与演化过程,在天峻快日玛乡、城墙沟、石灰沟等地区详细野外观测的基础上,利用地层恢复和古构造应力反演技术对柴北缘及邻区石炭系—新生界构造观测数据进行分析。结果表明晚二叠世—中三叠世,柴北缘在南—北向挤压作用下向北俯冲碰撞,盆地内部上二叠—中三叠统缺失。晚三叠世开始,西秦岭斜向碰撞柴达木盆地,柴北缘进入造山阶段,所受挤压作用方向转变为北西—南东向,盆地内大范围缺失上三叠统。晚海西—印支期柴北缘内部二叠纪—三叠纪地层大面积剥蚀加之该期强烈挤压作用造成尕海南山石炭系与白垩系、旺尕秀煤矿石炭系与侏罗系之间的角度不整合,意味着下伏石炭系可能遭受强烈破坏。In order to investigate the Late Hercynian-Indosinian paleotectonic stress characteristics and tectonic evolution on the northern margin of the Qaidam Basin, the authors analyzed the data of Carboniferous-Cenozoic tectonic features obtained in Kuairimaxiang, Chengqianggou, Shihuigou and some other areas by using stratigraphic recovery and paleotectonic stress inversion techniques. Under the influence of SN compression, the north margin of Qaidam underwent northward subduction, collision and denudation in the Late Permian–Middle Triassic period. From the Late Triassic, the collision between western Qinling and Qaidam caused the change of the orientation of the compressive stress into NW-SE, which resulted in the considerable loss of the Upper Triassic strata and local deposition of the Upper Triassic conglomerate on the northern margin of the Qaidam Basin. An analysis shows that voluminous denudation of the Permian-Triassic strata and the angular unconformity between Cretaceous and Carboniferous strata in Gahainanshan area and between Jurassic and Carboniferous strata in Wanggaxiu area caused by strong compression might indicate the destruction of the underlying Carboniferous strata in Late Hercynian-Indosinian period.

关 键 词：柴达木盆地北缘 晚海西—印支期 构造形迹 地层恢复 古构造应力反演 挤压作用方向 

分 类 号：P553[天文地球—构造地质学] P551[天文地球—地质学]