| 库车坳陷-南天山盆山过渡带的收缩构造变形模式 |
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| 引用本文： | 漆家福,雷刚林,李明刚,谢会文,杨书江.库车坳陷-南天山盆山过渡带的收缩构造变形模式[J].地学前缘,2009,16(3):120-128. |
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| 作者姓名： | 漆家福 雷刚林 李明刚 谢会文 杨书江 |
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| 作者单位： | 1中国石油大学(北京) 油气资源与探测国家重点实验室, 北京 102249
2中国石油大学(北京) 资源与信息学院, 北京 102249
3中国石油 塔里木油田, 新疆 库尔勒 841000
4东方地球物理勘探公司 物化探事业部, 河北 涿州 072700 |
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| 基金项目： | 国家重点基础研究发展计划“973”项目（2006CB202301） |
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| 摘 要： | 用地面露头、地震和CEMP(连续电磁剖面法)勘探资料揭示的库车坳陷-南天山盆山过渡带构造变形特征难以用经典的“A型俯冲”冲断褶皱楔变形模型来解释,因而文中提出一种“分层变形、垂向叠置”的“非俯冲”收缩构造解释模型。所谓分层变形是指受古近系膏盐岩层和侏罗系含煤地层等软弱岩层分隔,不同深度的岩层发育不同的收缩变形样式;所谓垂向叠置是指不同层次的强变形带在垂向上叠置,不存在区域性大位移的拆离断层。位于盐岩层之上的新生界以滑脱褶皱变形为主,而盐下层的中生界沉积层及盆地基底则以收缩断裂变形为主。浅部的滑脱褶皱表现出紧闭背斜和宽缓向斜组合,背斜具有不对称形态,其核部在古近系盐岩层或侏罗系含煤地层中滑脱,可在陡翼发育破冲断层或缓翼发育顺层滑脱逆冲断层。深层断裂变形以向山脉倾斜的高角度基底卷入逆冲断层为主干断层,断层上盘形成冲断隆起,次级断层相对较少,下盘则发育一系列同向倾斜的次级逆冲断层构成楔状叠瓦冲断构造。深层断层向上延伸在古近系盐岩层中尖灭,部分次级断层向下延伸并在侏罗系含煤地层中或盆地基底面滑脱,但是主干逆冲断层高角度切入基底,向上则对应于浅层背斜的核部。基底卷入的高角度主干逆冲断层可能利用了先存正断层发生反转位移,并成为控制局部构造变形的主要构造要素。天山上升引起的垂直剪切作用是导致库车坳陷-南天山盆山过渡带发育高角度逆冲断层或促成先存正断层的反转的可能原因。
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| 关 键 词： | 收缩构造 构造样式 “非俯冲”模式 南天山 库车坳陷 |
A model of contractional structure for transition belt between Kuche Depression and Southern Tianshan Uplift |
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| QI Jia-Fu LEI Gang-Lin LI Meng-Gang XIE Hui-Wen YANG Shu-Jiang.A model of contractional structure for transition belt between Kuche Depression and Southern Tianshan Uplift[J].Earth Science Frontiers,2009,16(3):120-128. |
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| Authors: | QI Jia-Fu LEI Gang-Lin LI Meng-Gang XIE Hui-Wen YANG Shu-Jiang |
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| Institution: | 1State Key Laboratory of Petroleum Resource and Prospecting, China University of Petroleum(Beijing), Beijing 102249, China;
2Faculty of Geosciences, China University of Petroleum(Beijing), Beijing 102249, China;
3Tarim Oil Company of PetroChina, Korla 841000, China;
45th Division of Orient Geophysical Prospecting Company (BGP), CNPC, Zhuozhou 072700, China |
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| Abstract: | Abstract: The structural features of the Cenozoic contractional deformation in the transition belt between Kuche depression and southern Tianshan uplift have been revealed by geological outcrop, seismic data, well log and CEMP(Continuous Electromagnetic Profile)data; it is found that these features are difficult to be interpreted by the typical “A type” subduction model. This article advances a “non subduction” contractional deformation model, i.e., the “delaminating contraction and vertically stacking” model. The “delaminating contraction” means that different structural levels developed their own contractional structural style owing to the detachments caused by the salt rock of Paleocene Eocene and the coal bearing series of Jurassic. The “vertically stacking” means that the stronger deformation zones within various levels were stacked up vertically, and the thin skin contractional deformation of cover detachment was stacked up on the top of the basement involved contractional deformation, so that the detachment fault could not develop into a regional detachment fault with great horizontal displacement. Detachment folds were developed in the overlying sequence of Paleocene Eocene salt rock, but a fault system assembled with basement involved reverse fault, thrust, and inverse fault or normal fault was developed in the underlying sequence of Paleocene Eocene salt rock or Jurassic coal bearing series. The cover folds show the structural pattern with a closed anticline and an open syncline. The asymmetric anticline was detached within salt rock of Paleocene Eocene or coal bearing series of Jurassic and was cut off by a break thrust in the steep limb. A series of basement involved thrust with high angle dipping to southern Tianshan dominate the contractional deformation in the basement. A mini scale imbricate wedge thrust system was developed in the footwall of basement involved thrust with a high angle dip, and a basement cored faulted anticline was developed in the hanging wall. Most of fault systems in the lower level probably vanished toward the salt rock of Paleocene Eocene or coal bearing series of Jurassic; the high angle basement involved thrust tipped upward to the core of detachment anticline in the shallower level, so that the salt rock or coal bearing series was an important transfer level. The high angle basement involved thrust may have been formed by the reverse displacement of a pre existing normal fault and led to the local structural deformations. The occurrence of the high angle thrust or the reverse of the pre existing normal fault may be attributed to the dynamics of vertical shearing caused by the uplift of southern Tianshan. |
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| Keywords: | Key words: contractional structure structural style “non subduction” model Southern Tianshan Kuche Depression |
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