| 摘要: |
| 在1991年中法合作渤海潮流沉积研究的基础上，查阅了国内外有关研究成果，分析了中国陆架的水深地形、沉积地貌与潮流动力的关系，认为潮流对中国陆架的海底地貌和沉积的形成发育起了主导作用。当潮流流速大于3节时，潮流的侵蚀作用是主要的，往复潮流多形成冲刷深槽，大大刷深了海峡或水道。当潮流流速1–3节时，潮流的沉积作用是主要的，多形成浅滩，即潮流沙脊和潮流沙席。以M2分潮椭率绝对值0.4为界，大于0.4者意味着潮流旋转性强，多形成潮流沙席；小于0.4者意味着潮流往复性强，多形成潮流沙脊。提出了我国邻近陆架发育了5个现代潮流沉积地貌体系：（1）黄海东部潮流沉积体系，它由西朝鲜湾潮流沙脊和其南部的沙席两者组成；（2）渤海东部潮流沉积体系，它由老铁山水道冲刷槽，辽东浅滩沙脊和渤中浅滩沙席三者组成；（3）长江口外潮流沉积体系，它由江苏滨外潮流沙脊和长江口浅滩潮流沙席组成；（4）台湾滨外潮流沉积体系，它由台湾海峡冲刷槽、台湾浅滩沙脊、澎湖水道冲刷槽和台中浅滩沙席四者组成；（5）琼州海峡潮流沉积体系，它由琼州海峡冲刷槽、东浅滩沙脊和西浅滩沙脊三者组成。此外，在东海陆架上还有冰后期海侵早期形成的残留潮流沉积体系。全新世陆架浅海潮流沉积模式可分海峡-浅滩型和一般浅滩型两种。 |
| 关键词: 中国陆架 潮流沉积体系 沉积模式 全新世 |
| DOI： |
| 分类号: |
| 基金项目:国家自然科学基金资助项目，48970272号 |
附件 |
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| TIDAL DEPOSITIONAL SYSTEMS AND PATTERNS OF CHINA'S CONTINENTAL SHELF |
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LIU Zhen-xia,XIA Dong-xing,WANG Kui-yang
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First Institute of Oceanography State Oceanic Administration, Qingdao, 266003
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| Abstract: |
| Based on a cooperative study between China and France on tidal deposits in the Eastern Bohai Sea in 1991, interrelationships between water depth, sediments, bed forms and tidal currents on China's continental shelves were analyzed. The results show that tidal currents play a major role in the creation of the present submarine geomorphology and depositional processes on China's shelves. If the tidal-current velocity exceeds 3 knots, then erosional action dominates and rectilinear currents form mostly deep scour furrows. When the tidal-current velocity ranges between l and 3 knots, deposition is dominant, and tidal currents form tidal shoals, i. e., tidal sand ridges and tidal sand sheets. The boundary between the ridges and the sheets lies near the location where the absolute value of the M2 ellipticity is 0.4. Where the absolute value is less than 0.4, tidal sand ridges are often formed in response to rectilinear currents. Where the absolute value exceeds 0.4, tidal sand sheets tend to be formed in response to rotatory currents. There are five modern tidal-depositional systems on China's continental shelves and the surrounding areas: (l) the tidal deposit over the eastern Yellow Sea (composed of tidal sand ridges in West Korea Bay and tidal sand sheets off South Korea); (2) the tidal deposits over the eastern Bohai Sea (composed of tidal scour furrows in the Laotieshan Channel, tidal sand ridges in the Liaodong Shoal and tidal sand sheets on the Bozhong Shoal); (3) the tidal depositional system off the Changjiang River estuary (composed of tidal sand ridges off the Jiangsu Province and tidal sand sheets on the Yangtze Shoal); (4) the deposits distributed to the west of Taiwan Island (composed of tidal scour furrows in the Taiwan Strait, tidal sand ridges over the Taiwan Shoal, tidal scour furrows in the Penghu Channel and tidal sand sheet on the Taizhong Shoal); and (5) the depositional system in the Qiongzhou Strait (composed of tidal scour furrows in the Qiongzhou Strait, tidal sand ridges on the eastern and western shoals). In addition, there are moribund tidal deposits in the East China Sea which formed during an early stage of the last transgression. The Holocene tidal-deposits on China's continental shelves can be divided into a strait-shoal type and an ordinary shoal type. |
| Key words: China's shelves, Tidal depositional systems, Depositional patterns, Holocene |
