| 塔里木盆地巴楚隆起北缘吐木休克弧形基底卷入斜向滑移构造 |
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| 引用本文： | 杨庚,陈竹新,刘银河,王晓波.塔里木盆地巴楚隆起北缘吐木休克弧形基底卷入斜向滑移构造[J].吉林大学学报(地球科学版),2019,49(5):1209-1221. |
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| 作者姓名： | 杨庚 陈竹新 刘银河 王晓波 |
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| 作者单位： | 中国石油勘探开发研究院/提高石油采收率国家重点实验室, 北京 100083 |
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| 基金项目： | 国家科技重大专项（2016ZX05003-001）；中国石油天然气股份有限公司科技重大专项（2019B-0503，2016E-0601） |
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| 摘 要： | 石油地震资料揭示塔里木盆地中央巴楚隆起为结晶基底和古生代地层相对隆升区，地表为第四纪陆相碎屑岩不整合覆盖，隐伏隆起大部分区域缺失中、新生界。在隆起南北两侧构造变形比较强烈，均发育基底卷入的逆冲构造和古生界内逆冲构造。根据钻井资料和二维地震测线详细的构造解释，应用断层相关褶皱理论得知：吐木休克基底卷入逆冲断层是在中生界早期形成的基底卷入楔形构造的基础上，在新生界晚期再次活动形成的；新生代晚期中亚地区强烈陆内变形，导致塔里木盆地先期形成的巴楚隆起再次挤压隆升；晚期变形过程中，先存构造与形成新构造挤压方向的偏差导致新构造发育有走滑分量，形成典型的斜向挤压构造——吐木休克旋转弧形构造。平面分布上，弧形构造东西向延伸的中段和北东向延伸的西段，早期为基底卷入楔形构造，晚期发育基底卷入逆冲构造；近北西向延伸的东段，晚期发育基底卷入楔形构造叠加在早期基底卷入楔形构造之上，说明该构造至少经历了两期变形。由于晚期基底卷入逆冲断层具有走滑分量，导致盖层单斜构造发育3类应变带及相应构造：拉伸变形带发育的正断层、剪切变形带发育的走滑断层及挤压应变带即走滑构造分量；西段发育左行逆冲走滑断裂带及伸展变形；东段发育右行逆冲走滑断裂带。弧形构造西部发育的构造样式与2012年Keating等模拟的斜向断层位移形成的构造样式非常相似，说明弧形构造西段吐木休克基底卷入逆冲构造具有走滑分量，从而合理地解释了该区发育的构造样式及正断层形成机制。
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| 关 键 词： | 塔里木盆地 巴楚隆起 基底卷入 弧形构造 斜向滑移 正断层 |
| 收稿时间： | 2018-03-06 |
A Basement-Involved Structure Above Oblique-Slip Tumuxiuke Fault in Northern Margin of Bachu Uplift in Tarim Basin,Northwest China |
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| Yang Geng,Chen Zhuxin,Liu Yinhe,Wang Xiaobo.A Basement-Involved Structure Above Oblique-Slip Tumuxiuke Fault in Northern Margin of Bachu Uplift in Tarim Basin,Northwest China[J].Journal of Jilin Unviersity:Earth Science Edition,2019,49(5):1209-1221. |
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| Authors: | Yang Geng Chen Zhuxin Liu Yinhe Wang Xiaobo |
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| Institution: | Research Institute of Petroleum Exploration and Development, PetroChina/State Key Laboratory of Enhanced Oil Recovery, Beijing 100083, China |
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| Abstract: | Seismic data show that the crust of the buried Bachu uplift in the central Tarim consists of the crystalline basement and Paleozoic strata, without Mesozoic and Cenozoic strata, and is unconformly covered by Quaternary terrestrial clastic rock. Both north and south margins of the Bachu uplift present intense deformation with basement-involved structures and thrust fault under the Paleozoic cover. A large-scale northward arcuate structure of the Tumuxiuke basement-involved fault is developed in the north margin of the Bachu uplift. By use of the fault-related theories, we interpreted 2D seismic data with the strata determined by the well logging data, and concluded that the Tumuxiuke basement-involved fault was formed by reactivation of the pre-existing basement-involved wedge-shaped structures. The Late Cenozoic India-Asia collision caused intense intracontinental deformations in the Central Asia and the reactivation of the Bachu uplift. It is unlikely that the pre-existing structures are perfectly perpendicular to the applied contraction direction of the new tectonic event,and most of these structures should consequently experience a strike-slip motion during the reactivation and the arcuate Tumuxiuke basement-involved fault was deformed by the progressive bending of once-straight structural trends (the pre-existing Tumuxiuke basement-involved wedged-shaped structure) during this time. The seismic data show that a wedge-shaped basement-involved structure is clear in the east part, but unclear in the west and central parts of the arcuate Tumuxiuke thrust belt, where many normal faults were formed in anticline core or fore-limbs of monoclines in the seismic reflection sequences. On the top and west parts of the orocline, the late basement-involved faults were developed on the pre-existing Tumuxiuke basement-involved wedge-shaped structures. On the east part of the orocline, the late Tumuxiuke basement-involved wedge-shaped structure reactivated the pre-existing wedge-shaped one. Our interpretations state clearly that there were three general strain zones and corresponding structures in the caprock monoclines that formed the above oblique-slip Tumuxiuke basement-involved fault in the western part of the arc-shaped structure, which is very similar to the physical modeling by Keating et al. (2012), but only in the two strain zones (extension and contraction) on the top of the arc-shaped structure. The extension faults are dominant in the upper-hinge region, while the contraction faults are dominant in the lower-hinge region, and the strike-slip faults are dominant in the middle of the fold limb. The boundaries of these three zones and the magnitude of strain in each zone vary with the oblique slip determined by its position in the arcuate structure. |
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| Keywords: | Tarim basin Bachu uplift basement-involved actuate structure oblique-slip normal fault |
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