The complex transgression and regression history of the northern margin of the Palaeogene Tarim Sea (NW China), and implications for potential hydrocarbon occurrences

• Published in: Marine and petroleum geology Vol. 112; p. 104041
• Main Authors: Lv, Dawei, Song, Ying, Shi, Longqing, Wang, Zeli, Cong, Peizhang, van Loon, A.J. (Tom)
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2020
• Subjects: Epicontinental sea; Palaeogene; Sea-level changes; Sequence stratigraphy; Tarim basin; Transgressions; Sequence stratigraphy; Sea-level changes; Tarim basin; Transgressions; Palaeogene; Epicontinental sea
• ISSN: 0264-8172; 1873-4073
• DOI: 10.1016/j.marpetgeo.2019.104041

The Tarim Basin is an epicontinental marine basin that developed during the Palaeogene in the eastern margin of the Paratethys Ocean. Palaeoclimate models suggest that sea-level fluctuations were the main driving force causing the Palaeogene aridification of Asia's interior and the increase in monsoon intensity. The Palaeogene succession in the northern margin of the south-western Tarim Basin is composed of five lithofacies associations in which two third-order sequences and three third-order sequence boundaries are present that correspond a complex history of trans- and regressions. Sequence 1 formed in an epicontinental sea during the Palaeocene and early Eocene, whereas Sequence 2 represents a transitional stage from marine to terrestrial conditions during the late Eocene and Oligocene. Part of this development was synchronous with the development along the southern margin of the south-western Tarim Basin, but the transition from marine to continental along the northern margin of the south-western Tarim Basin did not take place until the late Eocene, when the sea retreated westwards. The present contribution can help reconstruct the Palaeogene palaeogeography of the Paratethys regions and may also facilitate paleoclimate modelling for central Asia. It also suggests that there is a good hydrocarbon potential in the western and southern parts of the south-western Tarim Basin. •Two third-order sequences in the south-western Tarim Basin were present.•A transition from a marine to a continental environment (41–42 Ma) was found.•Trans- and regressions were different between the northern and southern parts.•Good hydrocarbon potential was concluded in study area.