南海北缘一统暗沙附近深水等深流沉积体系特征  

Deep-Water Contourite Depositional System in Vicinity of Yi'tong Shoal on Northern Margin of the South China Sea

作　　者：陈慧[1] 解习农[1] 毛凯楠[1] 

机构地区：[1]中国地质大学构造与油气教育部重点实验室,湖北武汉430074

出　　处：《地球科学（中国地质大学学报）》2015年第4期733-743,共11页Earth Science-Journal of China University of Geosciences

基　　金：国家自然科学基金(Nos.41372112;91028009);国家重点油气专项(No.2011ZX05025-002-02);教育部"111"引智计划(No.B14031)

摘　　要：利用高分辨率2D地震资料揭示南海北缘一统暗沙附近（水深700~1 000m）发育海山相关的深水等深流沉积体系,为南海北部陆缘深水洋流循环和深海动力学研究,以及深水油气矿产资源勘探提供了新的资料.一统暗沙南、北两侧发育边缘侵蚀槽沟,其中北缘的边缘槽沟可称为＂环槽＂,反映底流（可能属于南海中层水循环体系）自西向东流经海山.一套等深流沉积的伸长状-丘状漂积体沿环槽北岸发育.一统暗沙南侧和背侧还发育黏附型漂积体、南侧沉积区和补丁型漂积体.地震沉积记录显示该区稳定底流侵蚀-沉积活动可追溯至晚中新世早期.Using high-resolution 2D seismic data, this study reveals the presence of a deep-water contourite depositionaI system that developed in vicinity of the Yi＇tong Shoal （700--1 000 m depth）, on the northern margin of the South China Sea. The de- velopment of a moat north of the Yi＇tong Shoal indicates eastward flowing bottom currents, which might belong to the South China Sea Intermediate Water Circulation. Due to the coriolis deflection, an elongated-mounded drift is developed to the north of the moat. A marginal trough, a plastered drift and a deposition zone developed south of the Yi＇tong Shoal, indicative of rela-tively weak hydrodynamics in the south side. A shadow zone downstream of the Yi＇tong Shoal was generated where the currents slowed down, developing a depositional tail. Seismic stratigraphy shows that the initial development of the deep-water contou- rite depositional system was developed from the early Late Miocene （11.6 Ma）.

关 键 词：一统暗沙 深水等深流沉积体系 底流 海洋地质 

分 类 号：P736.21[天文地球—海洋地质]