The Tertiary evolution of the prolific Nanpu Sag of Bohai Bay Basin, China

Constraints from volcanic records and tectono-stratigraphic sequences

Yuexia Dong, Long Xiao*, Haimin Zhou, Chunzeng Wang, Jianping Zheng, Ning Zhang, Wenchen Xia, Qian Ma, Jingxia Du, Zhongxin Zhao, Hongxiang Huang

*Corresponding author for this work

Research output: Contribution to journalArticle

50 Citations (Scopus)

Abstract

The Bohai Bay Basin, located on the eastern Asian margin, is the second largest oil-production basin in China. It contains numerous depressions and sags, among which Nanpu Sag has become particularly important because of signifi cant oil discoveries in recent years. Geologically and tectonically, however, the rifting mechanism and geodynamic evolution of the basin remain uncertain. This paper uses detailed volcanic and stratigraphic records obtained through extensive drilling and sampling in Nanpu Sag to interpret tectono-stratigraphic sequences and discuss basin dynamic evolution and crustmantle interactions of the Bohai Bay Basin. Nanpu Sag contains voluminous volcanic rocks of dominantly alkaline basalts. Drill core samples, well logs, and seismic profiles reveal three volcanic cycles between the Eocene and Miocene Epochs. These basalts were created during a transition from garnet- to spinel-peridotite. Five tectono-stratigraphic sequences produced by episodic continental rifting have been identifi ed, each composed of a basal coarse clastic sequence, a lower volcanic sequence, a middle deep-water clastic sequence, and an upper infilling sequence. Tectonically, Nanpu Sag experienced four evolutionary phases. The fi rst three corresponded to three rifting events revealed by cyclic volcanism and sedimentary depositional features. The fourth phase was marked by extreme thermal subsidence and prograding fluvial deposition followed by tectonic inversion. A diapiric upper-mantle upwelling model is proposed to explain the dynamics that controlled the multiple rifting processes, the cyclic volcanism, and the periodic tectonic evolution of Nanpu Sag and the greater Bohai Bay Basin.

Original languageEnglish
Pages (from-to)609-626
Number of pages18
JournalBulletin of the Geological Society of America
Volume122
Issue number3-4
DOIs
Publication statusPublished - 2010
Externally publishedYes

Fingerprint Dive into the research topics of 'The Tertiary evolution of the prolific Nanpu Sag of Bohai Bay Basin, China: Constraints from volcanic records and tectono-stratigraphic sequences'. Together they form a unique fingerprint.

Cite this