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。
Influence factors including compressive stress and time,salt rock occurrences,pre-existing salt diapirs,pre-existing basement faults and basement uplift of the Kelasu tectonic belt are analyzed through discrete element numerical simulation on the basis of the interpretation of3D seismic profiles in the Kelasu tectonic belt of the Kuqa foreland thrust system.Discrete element numerical simulation results show that the duration time is a much more significant factor of deformation than the magnitude of compressive stress itself,which leading to greater uplift amplitude and larger horizontal deformation range.The pre-existing salt diapir contributes significantly to the scale of vertical deformation,and thus increases the uplift.The pre-existing faults mainly influence the range of horizontal deformation,i.e.,extending the reaches of the horizontal deformation.Basement uplift and the salt distribution pattern also have important influences on the deformation of the Kelasu tectonic belt.Salt rock gathered in the stress weak band near the basement uplift.Due to the buffering of salt rocks,deformation of the upper-salt layer is relatively weak.Anticlines and thrust structures may develop in the extrusion frontier and wide gentle syncline gradually may form near the basin.
作者
李维波
李江海
王洪浩
黄少英
能源
LI Weibo;LI Jianghai;WANG Honghao;HUANG Shaoying;NENG Yuan(Institute of Scientific and Technical Information of China, Beijing 100038, China;MOE Key Laboratory of Orogenic Belts and Crustal Evolution, School of Earth and Space Sciences, Peking University, Beijing 100871,China;Institute of Oil and Gas, Peking University, Beijing 100871, China;Research Institute of Tarim Oilfield Company, PetroChina, Korla 841000, Xinjiang, China)
出处
《大地构造与成矿学》
EI
CAS
CSCD
北大核心
2017年第6期1001-1010,共10页
Geotectonica et Metallogenia
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
关键词
库车前陆冲断带
离散元数值模拟
克拉苏构造带
影响因素
变形特征
Kuqa foreland thrust belt
discrete element numerical simulation
Kelasu tectonic belt
influence factors
deformation characteristics
