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Nghi Tran, Ha Noi University of Sciences (Vietnam)
Tien Dao Manh, Marine Geology Union (Vietnam)
Thanh Dinh Xuan, Ha Noi University of Sciences (Vietnam)
Tin Nguyen Trong, Vietnam Petroleum Institute (Vietnam)
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Eastern Sea of Vietnam is a semi open sea that bounded by archipelagos, islands, mainland and connected partially with Pacific and Indian Ocean. Total water surface area of it is about 2,974,600 km2 and to be one of the widest semi open sea in the world. From 1960s to now, Vietnamese and foreign geoscientists have researched and got sample as well as mapping the geological map of Eastern Sea but there is still without guidance and right methods for mapping, especially in presenting geological units on geological map. So that, in this article the authors proposed principle of mapping of geological map of Eastern Sea with Cenozoic stratigraphic divisions and present them on the map.
Principle for mapping Cenozoic formations presented on the continental shelf is dividing into different geological units on the map based on stratigraphic units in vertical reflection direction by overlapping these units together and main fault systems that controlled geological structure types and basin forming, besides each of geological unit were colored by a special color. Perimeter of each geological unit is coincided with 0m isopath. There are four stratigraphic units in Eastern Sea: Eocene (E2); Oligocene (E3); Miocene (N1) and Pliocene ? Quaternary (N2-Q). Base on exposed area of each stratigraphical unit, the geological units will be identified and presented on the geological sea map. For example the exposed area of these stratigraphical units have upward ranking as follow: Eocene (E2); Oligocene (E3); Miocene (N1) and Pliocene ? Quaternary (N2-Q) and boundary between them is zero isopath and the geological units were presented on the map including: Eocene-Oligocene-Miocene-Pliocene-Quaternary (E2E3N1N2Q); Oligocene-Miocene-Pliocene-Quaternary (E3N1N2Q), Miocene-Pliocene-Quaternary (N1N2Q) and Pliocene-Quaternary (N2Q). By this principle, the geological map of Eastern Sea was mapped and presented clearer and more useful in using as a basic bottom sea map.
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