塔里木盆地东北缘盖层不整合序列及其构造演化

塔里木盆地东北缘新元古界-新生界中分布多期不整合界面。它们是不同地球动力学背景的产物，也是研究塔里木盆地东北缘乃至整个盆地构造演化的重要依据。通过野外地质调查和盆地内地震资料的综合研究，进一步阐述Nh₂/Nh₁、∈/Z 、O₃/O₂、S/O₃、C/AnC、T/AnT、J/AnJ、E/AnE和N₂/N₁重要的不整合面特征及其形成的地球动力学背景，建立了研究区完整的盖层不整合演化序列。根据不整合面特征,结合地层、沉积和构造特征将塔里木盆地东北缘盖层构造演化划分为3个旋回、6个阶段：（1）南华纪-泥盆纪克拉通内裂解和闭合旋回,（2）石炭纪-三叠纪克拉通边缘裂解-闭合旋回,（3）侏罗纪-第四纪拉张-挤压旋回;①南华纪-奥陶纪克拉通内坳拉槽阶段,②志留纪-泥盆纪挤压隆升阶段,③石炭纪-早二叠世克拉通内坳陷盆地阶段,④早二叠世末期冲断走滑-三叠纪前陆盆地阶段,⑤侏罗纪-古近纪断陷-坳陷盆地阶段,⑥新近纪-第四纪再生前陆盆地阶段。

Sequence of Unconformities and Tectonic Evolution of the Covers at the Northeast Margin of the Tarim Basin

Numerous unconformities occur in the Neoproterozoic-Cenozoic cover sequence at the northeast margin of the Tarim Basin. They are the products formed under different geodynamic settings and provide important clues to the study on the tectonic evolution both at the northeast margin of and of the whole Tarim basin as well. Based on field geological survey and comprehensive study of the seismic materials of the basin, the authors further elaborate the features of the important unconformity interfaces of Nh₂/Nh₁，∈/Z ，O₃/O₂，S/O₃，C/AnC，T/AnT，J/AnJ，E/AnE，N₂/N₁ and their geodynamic background and try to set up a complete evolution sequence of unconformities in the area. According to the features of the unconformities，strata ,deposit and structure, the tectonic evolution of the covers at the northeast margin of Tarim basin can be divided into three cycles and six stages. The three circles are: the Nahuaian-Devonian intra-craton disintegration and closure, the Carboniferous-Triassic circum-craton disintegration and closure and the Jurassic-Quaternary pull-apart and compression. The six stages are: Nahuaian-Ordovician intra-craton aulacogen, Silurian-Devonian compression and uplifting, Carboniferous-Permian intra craton subsidence basin, thrust-strike-slip of the last stage of Lower Permian-Triassic foreland basin, Jurassic-Paleogene fault depression and down-warped basin and Neogene-Quaternary regenerated foreland basin stages.