库车坳陷西部阿瓦特—博孜地区构造变形差异及数值模拟分析  

Structural deformation differences and numerical simulation analysis of Awate-Bozi area in the western Kuqa Depression

作　　者：谢会文[1] 陈龙 吴超[1] 陈汉林[2,3] 顾成龙[1] 程晓敢 Xie Huiwen;Chen Long;Wu Chao;Chen Hanlin;Gu Chenglong;Cheng Xiaogan(Tarim Oilfield Company,PetroChina,Korla,Xinjiang 841000;School of Earth Sciences,Zhejiang University,Hangzhou 310027;Structure Research Center of Oil&Gas Bearing Basin of Ministry of Education,Hangzhou 310027)

机构地区：[1]中国石油塔里木油田公司,新疆库尔勒841000 [2]浙江大学地球科学学院,杭州310027 [3]教育部含油气盆地构造研究中心,杭州310027

出　　处：《地质科学》2024年第4期1082-1097,共16页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：国家自然科学联合基金项目(编号:U22B6002);超深研发中心和超深层碎屑岩重大专项(编号:2023ZZ14YJ02)资助。

摘　　要：库车坳陷西部的阿瓦特-博孜地区位于构造挤压转换区,沿走向构造变形差异显著。本文基于最新的三维地震资料和离散元数值模拟方法,对该区域进行了精细的地质建模,模拟了其形成演化过程,讨论了差异变形的控制因素。阿瓦特地区盐下沿克深断裂远距离逆冲推覆,形成上下叠置的两套沿侏罗系煤层滑脱的逆冲体系;盐上发育厚度较小的阿瓦特凹陷;盐构造以不整合型为主。博孜地区盐下在克深断裂以北为高角度基底卷入变形,以南为沿煤层的滑脱,整体为楔形叠瓦冲断构造;盐上发育厚度巨大的拜城凹陷;盐构造以整合型为主。模拟结果表明,温宿古隆起限制了中生界至古近系的沉积范围,阻碍了变形的向前传递,是造成阿瓦特-博孜地区变形差异性的最主要原因。先存盐底辟构造和南天山的差异挤压作用对该区域的差异变形也具有一定的控制作用。综合地震剖面解释和数值模拟结果的演化过程表明,该区域构造活动具有由弱到强的变化趋势,构造变形开始于早中新世吉迪克组沉积时期,在上新世早期康村组沉积之后发生显著的构造加速事件。The Awate-Bozi area in the western Kuqa Depression is located in a tectonic transition zone of compression,where the structural deformation varies significantly along the strike.Based on the latest three-dimensional seismic data and discrete element numerical simulation method,this paper presents a detailed geological modeling of the region,simulates its formation and evolution processes,and discusses the controlling factors of differential deformation.In the Awate area,subsalt thrusting occurs along the Keshen fault over a long distance,forming two sets of overlying thrust systems,both of which detach along the Jurassic coal seam;the Awate sag with relatively small thickness develops above the salt;the salt structures are mainly uncomformity-type.In the Bozi area,subsalt deformation north of the Keshen fault is characterized by basement-involve deformation,while to the south it manifests as detachment along the coal seam,with the overall structure being a wedge-shaped imbricate thrust system;the Baicheng sag with huge thickness develops above the salt;the salt structures are mainly comformity-type.The simulation results show that the Wensu paleo-uplift is the main cause of differential deformation in Awate-Bozi area,which restricts the sedimentary range from Mesozoic to Paleogene and impedes the forward transfer of deformation.Pre-existing salt diapir and the differential compression of the southern Tianshan also play a certain role in controlling the deformation in the region.The evolutionary process based on seismic profiles and numerical simulation results suggests the regions tectonic activity has a trend of intensifying from weak to strong:tectonic deformation began during the deposition of the Jidike Formation in the Early Miocene,followed by a significant tectonic acceleration event after the deposition of the Kangcun Formation in the Early Pliocene.

关 键 词：库车坳陷西部 构造建模 离散元数值模拟 古隆起 差异变形 盐底辟 

分 类 号：P542[天文地球—构造地质学]