| 南海北部陆坡晚白垩世构造逆冲及其成因 |
| |
| 引用本文： | 王长势,朱伟林,钟锴,许长海.南海北部陆坡晚白垩世构造逆冲及其成因[J].地球科学,2015,40(9):1505-1516. |
| |
| 作者姓名： | 王长势 朱伟林 钟锴 许长海 |
| |
| 作者单位： | 1.同济大学海洋地质国家重点实验室, 上海 200092 |
| |
| 基金项目： | 国家重大科技专项项目2011ZX05023-003-003 |
| |
| 摘 要： | 地震资料显示南海北部中生界发育褶皱和逆冲断层等挤压构造, 但目前对其成因仍存在争议.通过对南海北部珠江口盆地东南部陆坡的二维地震剖面进行研究, 发现在云荔低隆起-兴荔凸起-兴宁凹陷一带存在2条近NW-SE走向并往NE方向逆冲的逆断层, 在东沙隆起南部有2条近南-北走向并具有压扭性质的走滑断层, 上述4条断层的平面延伸距离分别约为130、110、55和58 km.综合分析可知, 现今位于南海南部的礼乐-巴拉望地块经中侏罗世-早白垩世与华南陆缘发生软碰撞后, 在晚白垩世与华南陆缘在现今荔湾-兴宁凹陷一带进行最后的"焊接缝合", 而上述4条断层可作为该次"焊接缝合"的间接证据.由于太平洋向华南的俯冲板片在晚白垩世发生了后撤, 华南大陆边缘在晚白垩世末开始张裂之前可能整体为区域均衡抬升、局部陆-陆碰撞缝合的构造格局.
|
| 关 键 词： | 南海北部陆缘 礼乐-巴拉望地块 晚白垩世 逆冲断层 走滑断层 碰撞缝合 均衡抬升 海洋地质 |
| 收稿时间： | 2015-04-01 |
Late Cretaceous Tectonic Thrusting and Its Genesis in Northern Slope of the South China Sea |
| |
| Abstract: | There are folds and thrust faults in Mesozoic strata in the northern continental margin of the South China Sea, however, their geneses are still in controversy. In this study, 2D seismic profiles in the southeast region of the Pearl River Mouth basin (PRMB) are interpreted. Two northeastwards thrusting faults with approximately NW-SE strike are identified in the area of Yunli lower uplift, Xingli rise and Xingning sag, and two approximately north-south striking compressional strike-slip faults are distinguished in the southern area of Dongsha uplift. The 4 faults mentioned above are about 130, 110, 55 and 58 km long, respectively. It can be concluded that the Liyue (Reed) Bank-Palawan block which lies in the southern continental margin of the SCS underwent a soft collision with South China continental margin in Middle Jurassic to Early Cretaceous, and they finally united and sutured in Late Cretaceous approximately along Liwan to Xingning sags. The afore-mentioned 4 faults may be the circumstantial evidences for the final uniting and suturing between the Liyue Bank-Palawan block and the South China continental margin in the Late Cretaceous. Because of the retreat of the Pacific subducting slab in the Late Cretaceous, the overriding South China continental margin regionally and isostatically uplifted before it began to rift in the latest Cretaceous, whereas the coeval collision between the Liyue Bank-Palawan block and the South China continental margin was localized in the southeast of the PRMB. |
| |
| Keywords: | |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
| 点击此处可从《地球科学》浏览原始摘要信息 |
| 点击此处可从《地球科学》下载免费的PDF全文 |
|
