【摘要】 中国陆架残留沉积复盖面积达38.26万平方公里,占陆架总面积的30.1%.分布最广的残留沉积是滨岸相残留砂,其它还有少量的河流相、湖沼相、三角洲相、类黄土和古土壤等.残留砂的年龄大体在距今15000—7500年.残留沉积的存在取决于海面升降和现代沉积作用的不均衡性.中国陆架较大的残留沉积区有11个,其分布与海水流系格局密切相关,可分为四类:1.外陆架残留沉积;2.海湾残留沉积;3.海峡残留沉积;4.大河口外残留沉积.更多还原

【Abstract】 The China continental shelf covers an area of approximately 1271000km2, where relict sediment area is about 383000km2 and makes up 30.1% of the total shelf. The most important of them are plimpset sediment. The coastal deposit which is called relict sand is main genetic type. In addition, the genetic types are fluvial, deltaic, lake deposites, fossil soil and loessal deposit and so on. Relict sandes were formed in transgression duying the Latest Pleistocene and the begening of the Holocene. Data of 14C age of relict sands are 7500-15000 y.B.P., but some particles of relict sediment are multicycle deposits, theirs data may reach 30000-42000 y. B. P..Based on geographical distribution of relict sediments four types are divided. 1. Outer continental shelf relict sediments (in the East China Sea and the South China Sea); 2. The relict sediment in bay (in the Hangzho Bay and Beibu Bay); 3. Relict sediment of straits (in the Bohai Straits, the Taiwan Straits and east to Cengshantou Cape); 4. Relict sediment in the area off big river mouths (areas off the Changziang River and the Zujiang River Mouthes).Distribution of relict sediments is closely relateted to the ocean current system. Deposition in outer shelf is controleted by current system of outer sea and alongshore current that carry huge quantitis of sediment is difficul to reach there, so mordern sedimentation is of little significance in this areas. Hydrody-namism is of faint in bay and is advantageous to sedimentation, but becaus of short of material suppely relict sediment is reserved in some bays. Hydrody-namism is too strong in some areas of straits to deposits or because of erosion older strata are exposed. Hydrodynamism is complex in area off big rever mouth, sedimentation is active in some areas, and in ather areas deposition my by absent.更多还原