tailieunhanh - Báo cáo " Sequence stratigraphy of Quatemary depositions on the land and at the continental shelf of Vietnam "

The sequence stratigraphy units of the Quaternary sediments at the continental shelf of Vietnam have been compared with the lithofacies and depositional cycles in relation to sea level changes. During the regression phases corresponding to the lowstand systems tract has being formed the alluvial lithofacies, shelf deltaic complex and shelf edge fans complex. The maximum regression remarked by erosion boundaries has corresponded with the lowstand sea level characterized by the slope fan turbiditte complex. The transgression phase ilas lcaded to forru the ravinement surfaces and the transgressive systems tract deposits for the end of each sequence (depositional cycle). . | VNU Journal of Science Earth Sciences 25 2009 32-39 Sequence stratigraphy of Quaternary depositions on the land and at the continental shelf of Vietnam Tran Nghi Dinh Xuan Thanh Tran Thi Thanh Nhan Nguyen Dinh Thai College of Science VNU Received 8 April 2009 received in revised form 14 April 2009 Abstract. Tile sequence stratigraphy units of tile Quaternary sediments at the continental shelf of Vietnam have been compared with the lithofacies and depositional cycles in relation to sea level changes. During the regression phases corresponding to the lowstand systems tract has being formed the alluvial lithofacies shelf deltaic complex and shelf edge fans complex. Tile maximum regression remarked by erosion boundaries has corresponded with the lowstand sea level characterized by die slope fan turbiditte complex. The transgression phase has leaded to form the ravinement surfaces and Hie transgressive systems tract deposits for the end of each sequence depositional cycle . Keywords Lowstand sea level Highstand sea level Lowstand system tract Transgressive system tract Highstand system tract Deep water turbidite Progradation Healing phase. 1. Introduction So far the Quaternary stratigraphy lithofacies - paleogeography s ea bottom sediments depositional cycles in relation to sea level changes and tectonic movement . have been carried out by Tran Nghi Trinh The Hieu Nguyen Bleu 1991 - 2008 . The types of data used for analysis are based on the following principles - The lithologic composition thickness of Quaternary formations in the continental shelf of Vietnam are related with the sea level changes and tectonic movements. - The Quaternary sediments have cyclic composition granulometry mineralogy petrology geochemistry environmental geochemistry especially lithofacies associations . The boundaries of cycles have Corresponding author. Tel. 84-4-38542489. E-mail trannghi@ been divided based on fluvial erosion surface of transgress sive system tract Vinh Phuc .