| 柴达木盆地东部新生代盆地结构与演化 |
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| 引用本文： | 杜忠明,樊龙刚,武国利,魏红红,孟庆任.柴达木盆地东部新生代盆地结构与演化[J].地球物理学报,2016,59(12):4560-4569. |
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| 作者姓名： | 杜忠明 樊龙刚 武国利 魏红红 孟庆任 |
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| 作者单位： | 1. 中国科学院地质与地球物理研究所岩石圈演化国家重点实验室, 北京 100029;2. 中国科学院大学, 北京 100049;3. 中国科学院青藏高原研究所大陆碰撞与高原隆升重点实验室, 北京 100101 |
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| 基金项目： | 中国科学院战略性先导科技专项（B类）（XDB03010501），国家自然科学基金面上项目（41272238，91114204）共同资助. |
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| 摘 要： | 本文对柴达木盆地东部新生代盆地结构和构造演化进行了研究.地震剖面揭示柴达木盆地东部新生界分别向南、北盆地边缘变薄和尖灭,盆地北部被欧龙布鲁克山和埃姆尼克山隆起强烈改造.通过对新生代地层厚度横向变化以及地层剖面分析,确定欧北断裂自中新世晚期开始向北逆冲,导致欧龙布鲁克山发生隆升和德令哈凹陷的形成.埃北断裂从上新世开始活动,与欧北断裂同时向北逆冲,导致德令哈凹陷进一步沉降,形成厚度达2600m的狮子沟组.埃南断裂在第四纪开始大规模向南逆冲,不仅造成其北侧的欧龙布鲁克山和埃姆尼克山隆起强烈抬升和向南推覆,而且导致南侧霍布逊凹陷的形成,成为柴达木盆地第四纪沉积中心.早期提出的前陆盆地和背驮式盆地模型显然不能解释柴达木盆地东部新生代构造格架和演化历史.本次研究认为柴达木盆地东部的形成是强烈的水平挤压作用导致地壳发生大规模褶皱的结果,即柴达木盆地东部新生代是一个大规模向斜.该向斜盆地模型很好地解释了新生代地层向盆地边缘减薄以及沉积中心主要位于盆地中部等现象.了解柴达木盆地东部构造发展对了解青藏高原侧向扩展具有重要意义.
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| 关 键 词： | 柴达木盆地 新生代 地震剖面 沉积盆地 青藏高原 |
| 收稿时间： | 2016-04-06 |
Cenozoic architecture and structural development of the eastern Qaidam basin |
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| DU Zhong-Ming,FAN Long-Gang,WU Guo-Li,WEI Hong-Hong,MENG Qing-Ren.Cenozoic architecture and structural development of the eastern Qaidam basin[J].Chinese Journal of Geophysics,2016,59(12):4560-4569. |
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| Authors: | DU Zhong-Ming FAN Long-Gang WU Guo-Li WEI Hong-Hong MENG Qing-Ren |
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| Institution: | 1. State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;2. University of Chinese Academy of Sciences, Beijing 100049, China;3. Key Laboratory of Continental Collision and Plateau Uplift, Institute of Tibetan Plateau, Chinese Academy of Sciences, Beijing 100101, China |
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| Abstract: | This study aims to reveal Cenozoic architecture and structural development of the eastern Qaidam basin. Seismic profiles show that Cenozoic strata become thinner and pinch out toward the northern and southern edges of the basin, and the northern basin has been greatly modified by the Oulongbulukshan and Aimunikshan uplifts. Based on the analysis of lateral variations of Cenozoic strata and stratigraphic sections, it is demonstrated that the Oubei fault initiated in the Late Miocene, leading to rising of the Oulongbulukshan uplift and formation of the Delingha depression. The Aibei fault became active in the Pliocene, and north-directed thrusting of both the Aibei and Oubei faults resulted in further subsidence of the Delingha depression and deposition of the Shizigou Formation up to 2600 m thick. The Quaternary witnessed large-scale thrusting of the Ai'nan fault, which not only caused uplifting and southerly displacement of the Oulongbuluk mountain and Aimunik mountain on the north but also the generation of the Hobuxun depression on the south. The Hobuxun depression then became the depocenter of the eastern Qaidam basin. Previous basin models, such as foreland basin or piggyback basin models, apparently failed to interpret both the Cenozoic architecture and structural development of the eastern Qaidam basin. It is proposed that the eastern Qaidam basin was formed as a result of crustal folding related to strong horizontal compression, i.e., the eastern Qaidam basin was a crustal-scale synclinal basin. The synclinal basin model can well account for the thinning of strata toward basin margins and localization of depocenters in the middle of the basin during the Cenozoic. Reconstruction of structural evolution of the eastern Qaidam basin will help understand lateral growth of the northeastern Tibetan plateau. |
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| Keywords: | Qaidam basin Cenozoic Seismic profiles Sedimentary basin Tibetan plateau |
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