库车前陆冲断带克拉苏构造带变形影响因素分析——基于离散元数值模拟研究

发布时间：2018-08-09 17:18

【摘要】：在解释库车前陆冲断带克拉苏构造带三维地震剖面的基础上,采用离散元数值模拟手段、单因素变量控制方法,通过六组模拟对比实验,探讨挤压背景下应变速率大小和作用时间、盐岩展布形态、先存盐底辟、基底先存断裂以及基底古隆起等因素,对库车前陆冲断带克拉苏构造带变形的影响。离散元数值模拟结果表明:相比于应变速率大小,应力作用时间对冲断带变形的影响更为显著,变形缩短率相同时导致挤压隆升幅度更大,可达70.25%,向前传播距离均更远,横向上变形范围可达73.82%,盐下层叠瓦状逆冲断裂倾角更小。先存底辟主要影响挤压端垂向变形规模,使得隆升幅度更大。先存断裂主要影响挤压端水平方向变形范围,挤压变形水平传播更远。基底古隆起和盐岩展布形态对克拉苏构造带变形也具有重要影响,基底隆起前沿形成应力集中带,盐岩在此聚集形成构造三角带。由于盐岩的分隔作用,盐上层变形相对较弱,靠近挤压端发育背斜和冲断构造,向盆地方向逐渐变为宽缓的向斜构造。
[Abstract]:Based on the interpretation of 3D seismic profile of Klassou structural belt in Kuqa Foreland thrust belt, the discrete element numerical simulation method and single factor variable control method are adopted, and six groups of simulation and contrast experiments are carried out. The effects of strain rate, action time, distribution form of salt rock, pre-salt diapir, basement pre-existing fault and basement paleouplift on the deformation of Klassou tectonic belt in Kuqa Foreland thrust belt are discussed. The numerical simulation results of discrete element show that the effect of stress action time on the deformation of the thrust zone is more significant than that of the strain rate. When the deformation shortening rate is the same, the extruding uplift is larger, up to 70.25, and the distance of forward propagation is longer. The transverse deformation range can reach 73.82 and the dip angle of imbricate thrust faults under salt is even smaller. The existence of diapir mainly affects the vertical deformation scale of the extruded end, which makes the uplift greater. Preexisting faults mainly affect the horizontal deformation range of extrusion end, and the horizontal propagation of extrusion deformation is further. The paleouplift of the basement and the distribution of salt rock also have an important influence on the deformation of the Klassou tectonic belt. The stress concentration zone is formed at the front of the basement uplift and the tectonic triangle zone is formed by the accumulation of the salt rock. Due to the separation of salt rocks, the upper salt deformation is relatively weak, and the anticline and thrust structures are developed near the compressional end, gradually turning into broad and gentle syncline structures in the direction of the basin.
【作者单位】：中国科学技术信息研究所;造山带与地壳演化教育部重点实验室北京大学地球与空间科学学院;北京大学石油与天然气研究中心;中国石油塔里木油田研究院;
【基金】：国家科技图书文献中心重大专项服务项目“深地资源勘查开采重点专项服务”(2017)和“库车盐构造变形特征分析和区域变形场建立”(041013100040)联合资助
【分类号】：P542;P618.13

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