柯坪褶皱冲断带构造变形特征解析

柯坪褶皱冲断带位于塔里木盆地西北缘,勘探程度低,地表、地下构造变形复杂,构造模型存在多解性.本文通过对最新地震资料的解释,结合地质露头和钻井资料,建立起该地区新的构造模型.柯坪褶皱冲断带构造变形具有东西分段、南北分带的特征.东西向具有“跷跷板式”的沉积特征.中部皮羌段中寒武统盐层厚度大,主要发育盐下冲断构造和盐上反向滑脱构造;东、西两段主要发育基底卷入构造.石炭纪柯坪褶皱冲断带存在一期古隆起构造.晚石炭世一早二叠世沉积的康克林组具有填平补齐的特征.皮羌段发育两期断裂.早期为海西期断裂,晚期为喜山期断裂.石炭纪古隆起受控于早期断裂.喜山期形成的盐上滑脱构造对下伏潜在的古油藏具有封闭和保存作用.

Analysis of the structural deformation characteristics of the Kalpin fold thrust zone

Because of the limitation of the degree of exploration and the complex tectonic deformation of surface and subsurface, the structural model for Kalpin fold thrust zoneis of multiple solutions, which directly affects the exploration potentials of this area. Combing with previous research results and geological outcrop, seismic and drilling data, a new model for this area is developed, from which the following understandings are obtained：Tectonic deformation is characterized by apparent zonation from south to north, segmentation from east to west. East and west have “seesaw type” sedimentary characteristics, Middle Cambrian has a great thickness of salt so it’s mainly developed the decollement structure of the central in Piqiang segment but basement involved thrust mainly developed in east and west segments. palaeo-uplift formed in Carboniferous Period and it’s layer onlap deposit on Silurian and Devonian system are characterized by fill up and gaps. There are two-period fractures developed in Piqiang segment, early fractures are developed in Hercynian movement and late fractures are developed in Caledonian movement, early fractures mainly control the Carboniferous palaeo-uplift. The decollement structure which developed in Himalayan period is favourable for the sealing and preservation of paleo-reservoir. So Cambrain subsalt structural traps have significant exploration potential.