Stratigraphy of Palaeozoic Carbonate Rocks in North Vietnam

The study integrates stratigraphic and biostratigraphical data from outcrops in North Viet Nam to better understand the sedimentary environments of the Paleozoic carbonate rocks in Viet Nam. The studied Paleozoic carbonate successions are represented by six sedimentary stages. These stages are as follow: the Early Cambrian stage, represented by the Cam Duong and Coc Bai formations, the Middle Cambrian - Early Ordovician stage, represented by the Ha Giang, Chang Pung, Lutxia and Ham Rong formations, the Middle Ordovician - Silurian stage, represented by the Sinh Vinh, Bo Hieng and Kien An formations, the Devonian - Early Carboniferous stage, represented by the Khao Loc, Si Phai, Na Quan, Ban Coong, Ban Pap, Trang Kenh, Mo Nhai, Toc Tat, Pho Han, Con Voi, Lung Nam and Da Nieng formations, the Carboniferous - Middle Permian stage, represented by the Bac Son, Song Da and Na Vang formations and Late Permian stage, represented by the Deo Son La and Dong Dang formations. These stages are suggested to be of different environment of deposition during the different transgressive and regressive cycles. The Early Cambrian stage is suggested to be of stable continental shelf depositional environment. The Middle Cambrian - Early Ordovician, Middle Ordovician - Silurian, Carboniferous - Middle Permian and Late Permian stages are indicated to be of shallow marine environment. The Devonian - Early Carboniferous stage is suggested to be of littoral shallow marine environment in the lower part, and of deep - water troughs environment in the upper part