Discussing The Trace Of Tythys In The Area From Northern Slope To The Boundary Of Continent And Ocean Of South China Sea

Tethyan realm is a global structural realm on the world besides of Gondwana realm, Euro-Asian realm and Pacific realm. Its formation is due to a sequence opening and closing of Tethys Ocean in the low latitude area near the equator. This unique and eastward opening archipelagic ocean like a horn, and made violent influence to the evolution history of the global geologic structure. When Gondwana continent separated from Euro-Asian continent in the north, there produced a series of small oceanic basins. The formation of new oceanic basin was company with the extinction of the older ones. This recycling function made the formation of a huge structural zone in the low latitude zone near the equator. This huge structural zone-Tethyan realm cuts across European, Asian, African, South American and North American these five continents, and it made a great role in the evolution history of the global geologic structure; and its abundant petroleum resource is also attracting the petroleum geologists and industrialist's interest. In Tethyan realm, there are a lot of petroleum-containing depressions. As the contribution of Tethyan realm over the world, the depressions contribute in the low latitude area near the equator. The most famous petroleum-containing basin is Persian Gulf locates in Arabian area in western Asia. Generally speaking, the petroleum-containing depressions in Tethyan realm all have abundant petroleum resource. In these basins, the typical petroleum-containing sediment layer is mainly equator-enclosed type neritic face carbonate reef contain little shale, the organic type isâ… andâ…¡, and the cover is evaporitic rock. This sediment character typically has abundant petroleum perspective.The research about Tethys in China also has been done by many researchers since the concept began. But the topic about Tethys in South China Sea has also been quarreled as the work continues. At the beginning, the focus of the discussing is whether there is Tethyan realm in South China Sea or not. As the research about Tethyan realm on continent in China, accompanying with the development of geophysical method, we know more details about the Tethyan realm in South China Sea and its adjacent area. The Honghe fault zone in adjacent area of South China Sea belongs to Tethyan realm in structural property. The Honghe fault zone is relict suture zone of Tethys Ocean. This zone begins at Tibet plateau in the north, and it crosses Yunnan and northern Vietnam, and enters in South China Sea to the Southeast. Its length is about 1 000 kilometers. Our researchers have done a lot of work trying to find out its trace in South China Sea. With the support of more data, the idea of the research is the trace along the East Vietnam to the south or across South Hainan Island and linking the Xisha trough to the east. I want to choose one Tethyan model in Tethyan realm, and analysis the structural character and geophysical appearance of the Tethyan suture zone. Then I selected some OBS and DSRP data about northern slope of South China Sea to get the whole strata and structural framework. I build some gravitational models to reverse the texture of the layers in northern slope of South China Sea. I can get a macroscopic idea of the probability about the existence of the Tethyan realm in the northern slope of South China Sea. Furthermore, I will calculate the heat flow of the profiles in South China Sea, and discuss the relict of Tethyan realm in northern slope of South China Sea more particularly. It is generally about the eastward section of Honghe Fault in South China Sea.