| 摘要: |
| 东海陆架边缘的构造特征记录了有关冲绳海槽张裂过程的关键信息，对于进一步理解海槽的形成演化以及弧后张裂与弧-陆碰撞之间的相互作用至关重要。本文基于多道地震和重磁资料，分析了东海陆架边缘的地形和构造特征，并对冲绳海槽早期张裂过程、北西向断裂带的分隔控制作用、钓鱼岛隆起带南北构造差异和冲绳海槽的向西前展等问题进行了探讨。结果表明，冲绳海槽西侧陆坡存在的分段性，各分段在地形地貌、地层展布和构造特征等方面的不同，体现了其构造演化和现今构造活动性的差异。冲绳海槽中—北段的张裂始于陆架前缘坳陷，在晚中新世向东扩展至整个海槽，晚中新世至今以分散式张裂为主。北西向断裂带对东海陆架边缘不同分段的构造特征和构造活动起到了分隔控制和转换协调作用，控制了不同类型陆坡的形成和发育。受冲绳海槽在全宽度上向西前展的影响，钓鱼岛隆起带南段的基底隆起及其支撑的陆架边缘发生了破坏和沉降，形成基底起伏较大、地形崎岖不平的陆坡。 |
| 关键词: 东海陆架边缘 钓鱼岛隆起带 冲绳海槽 弧后伸展 构造 |
| DOI：10.11693/hyhz20171200311 |
| 分类号:P736 |
| 基金项目:国家自然科学基金项目，41606050号，41506080号，41506083号；中国海域1：100万海洋区域地质调查成果集成与应用研究项目，DD20160137号；国家重点基础研究发展计划项目，2013CB429701号。 |
附件 |
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| TECTONIC STRUCTURE OF THE OUTER SHELF OF THE EAST CHINA SEA AND THE FORMATION MECHANISM |
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SHANG Lu-Ning1, ZHANG Yong1, ZHANG Xun-Hua2, CAO Rui3, SUN Zhi-Lei1
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1.Qingdao Institute of Marine Geology, Qingdao 266071, China;2.Nanjing Center, China Geological Survey, Nanjing 210016, China;3.Qingdao Geo-Engineering Investigation Institute, Qingdao 266071, China
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| Abstract: |
| The evolution of the shelf of the East China Sea has been considered closely related to the back-arc rifting of the Okinawa Trough and its tectonic structure can provide important clues for the studies of the evolution of the Okinawa Trough and the interaction between the Okinawa back-arc rifting and the Taiwan arc-continent collision. Based on multichannel seismic, gravity, and magnetic data, we analyzed the morphological and structural characteristics of the continental shelf. Further, we discussed several disputed questions, such as the early rifting process of the Okinawa Trough, the NW trending strike-slip faults, and the roles they have played during the evolution of the shelf margin, the differences between the northern-middle Diaoyudao Uplift and the southern Diaoyudao Uplift, and the westward propagation pattern of the southern Okinawa Trough. The results suggest that the western slope of the Okinawa Trough can be divided into several segments of different topography, sediment strata, and tectonic structures, reflecting different evolution processes they have experienced and different tectonic activity levels of each segment. The rifting of the northern-middle Okinawa Trough was initiated in the Frontal Shelf Depression in middle Miocene. In late Miocene, the rifting spread eastward into the whole width of the trough. Since then, the northern-middle Okinawa Trough has been dominated by diverse rifting. The NW trending strike-slip faults bound different segments of the shelf and accommodate the stress fields between them. Influenced by the westward extension of the southern Okinawa Trough in its whole width, the basement high of the southern Diaoyudao Uplift and the shelf margin lay on it were severely destroyed, leading to the formation of the slope with undulate basement surface and rugged seafloor at present. |
| Key words: East China Sea Shelf Margin Diaoyudao Uplift Okinawa Trough back-arc extension tectonics |
