Cold-seep Related Bivalves At Northern Continental Slope Of South China Sea From SO177 During Upper-Pleistocene: The Discuss Of Community And Ecology

As the result of physical, chemical and biological processes of fluid seeping and diffusion into the sea water, the cold seeps and vents are now known to be common at continental margins worldwide, exuding fluids rich in low temperature water, hydrocarbon (gas and crude oil), H2S and teeming with life based on chemosynthesis. In these special settings, a largely endemic and chemosymbiotic biota, such as microbial mat, bivalves and gastropods, have been discovered, which may be related to the present of authigenic carbonate and gas hydrate. At the base of the ecological distribution and chemosynthetic food chain of these bivalve families, rapid growth rate become a important role in their developing process.So far the biggest gigantic methane-related carbonate rock has been observed in the north slope of South China Sea by Seabed TV through SO177, the SiGer Program collaborated by China and Germany in 2004. Depending on these active seep and CH4 eruption, microbial mat and bivalves appear in the crack of these carbonate crest and are obtained by means of Seabed TV grab in JiuLong Methane Reef and"HaiYang 4"Areas, which is the first time of getting so much cold-seep bivalve samples by crab.In the base of the identification results, the detailed morphology and internal structures of cold seep bivalves are described. Furthermore, the length and height of the valve are measured respectively. Integrating the qualitative and quantitative analysis, the characteristics of the cold seep bivalve on north continental slope in South China Sea are studied, and the cold seep bivalve community is reconstructed. Lastly, the relationship between cold seep community and hydrocarbon hydrate, valve feature and fluid activity are discussed.