摘要
板内中小滑移距走滑断裂因产状高陡、变形微弱,其地震识别与地质解析一直以来是构造领域研究的难点和重点.为加深对此类走滑断裂发育特征的认识,以塔里木克拉通盆地内部顺北4号走滑断裂为例,利用最新采集处理的高精度三维地震资料,对其空间结构及演化过程进行了精细解析,认为顺北4号断裂具有"平面分段多样性、纵向变形差异性、构造演化多期性"的特点,石油地质条件优越.研究结果表明:顺北4号断裂横跨塔北隆起、顺托果勒低隆起、塔中隆起3大构造单元,全长超过280 km,基于走向变化可将三维研究区内的顺北4号断裂划分为南段(NE48°)、中段(NE28°)、北段(NE42°),各段之间叠接面积超2 km^(2),南段和北段以叠接压隆构造发育为主,中段以叠接拉分构造发育为主;顺北4号断裂纵向自下而上发育"寒武系—中奥陶统高陡走滑断层"+"上奥陶统—石炭系雁列正断层"的分层变形样式,下部高陡断面在3个刚性—塑性岩性地层分界面普遍呈现走滑分段性,其中中—下奥陶统碳酸盐岩顶部可识别出13个断面,平均长度为8 km,上覆雁列正断层的活动强度与下部高陡走滑断层的应变分段性质有关;顺北4号断裂共经历了3期左行走滑活动,加里东中期Ⅲ幕在塔北—塔中体系对接过程中多段拼贴发育,加里东晚期和海西中—晚期均为雁列正断层活动,在三维研究区内呈现"南北弱、中部强"的活动特征.
Intraplate meso-micro scale strike-slip fault is hard to be recognized in seismic data and geological analysis due to its high dip angle and small displacement.To deepen the understanding of intraplate meso-micro scale strike-slip fault,a sample from the Shunbei 4 fault in the central Tarim Basin is used to further study in this paper.Based on the newly acquired high-accuracy 3 D seismic data,detailed structural analysis of the Shunbei 4 fault is conducted,systematically revealing that the Shunbei 4 fault has the characteristics of"diversity of plane segments,difference of layered deformation and multi-stage tectonic evolution",showing superior petroleum geological conditions.New findings include the following:The Shunbei 4 fault is characterized by a more than 280 km long fault trace continuing through the Tabei uplift,Shuntuoguole low uplift and the Tazhong uplift.Based on the change of strike orientations,the Shunbei 4 fault zone in the survey can be divided into three segments:the south segment(oriented about NE48°),the middle segment(oriented NE28°)and the north segment(oriented about NE42°).The area of the step-over zone between two adjacent segments is more than 2 km;.The south and north segments mainly developed push-up structures,while the middle segment mainly developed pull-apart structures.The Shunbei 4 fault is characterized by“layered deformation”in the profile.It displays subvertical segments as“principal displacement zone”at Cambrian-Middle Ordovician and en echelon normal fault zones at Upper Ordovician-Carboniferous.The steep principal displacement zone shows strike-slip segmentation at three rigid-plastic lithologic stratigraphy interfaces,among which 13 sections can be identified at the top of the middle-lower Ordovician carbonate rocks with an average length of 8 km.Activity intensities of en echelon normal fault zones are related to the properties of deep segments.The Shunbei 4 fault experienced three sinistral movements.In the 3 rd episode of the Middle Caledonian,multiple segmen
作者
刘雨晴
邓尚
LIU Yuqing;DENG Shang(SINOPEC Petroleum Exploration and Production Research Institute,Beijing 100083,China;SINOPEC Northwest Oilfield Company,Urumqi,Xinjiang 830011,China;MA Yongsheng's Laboratory,Beijing 100083,China)
出处
《中国矿业大学学报》
EI
CAS
CSCD
北大核心
2022年第1期124-136,共13页
Journal of China University of Mining & Technology
基金
国家自然科学基金企业创新发展联合基金项目(U19B6003)
中石化科技部项目(P20062)。
关键词
分层变形
雁列断层
构造演化
走滑断裂
塔里木盆地
layered deformation
en echelon fault
evolution model
strike-slip fault
Tarim Basin
