深水沉积物波及其在南海研究之现状

深水沉积物波的研究始于20世纪50年代。根据成因和结构特征，可以将深水沉积物波划分为细粒底流、细粒浊流、粗粒底流和粗粒浊流等类型。不同类型的沉积物波具有不同的形态、物质组成及分布特征。已提出的深水沉积物波的形成模式主要有背流波模式、逆行沙波模式、内波模式及底形和斜坡失稳混合模式等。1994年太阳号95航次和1999年ODP184航次揭示并证实，南海北部东沙岸外1144站所处的深水陆坡区发育有一高速沉积物牵引体。根据最新的地震资料分析发现，该牵引体实际上由一系列逆陆坡向上倾方向迁移的沉积物波组成，这一发现对于南海北部大陆边缘古海洋、古环境和古气候研究，以及南海深水油气勘探具有重要意义。

Current Status of Deep-water Sediment Wave Studies and the South China Sea Perspectives

Research on deep-water sediment waves was initiated in the 1950's.So far,significant progress has been achieved.It is been known that deep-water sediment waves are generated mainly by bottom currents or turbidity currents.Four main catalogues of deep-water sediment waves have been recognized according to their grain size of component sediments and formation processes: fine-grained bottom current sediment waves,coarse-grained bottom current sediment waves,fine-grained turbidity current sediment waves,and coarse-grained turbidity current sediment waves.Models presented for the formation of deepwater sediment waves include lee-wave model,antidune model,internal wave model and mixed bedform and failure model.Newly-acquired high-resolution seismic data revealed that the sediment drift with high deposition rates on the slope offshore Dongsha Islands,northern South China Sea was actually composed of a series of sediment waves migrated upslope.This finding is of great significance not only to the reconstruction of paleoceanography,paleoenvironment,paleo-tectonics,and paleoclimate,but also to deep-water petroleum exploration in the South China Sea.