Development of a distinct submarine depositional system on a topographically complex Niger Delta slope. (26th August 2019)

• Record Type: Journal Article
• Authors: Zhao, Xiaoming; Li, Minghua; Qi, Kun; Liu, Li; Hu, Guangyi; Wu, Wei; Zhang, Wenbiao; Ge, Jiawang
• Editors: Somerville, I.
• Is Part Of: Geological journal. Volume 55:Number 5(2020)
• Page Start: 3732
• Page End: 3747
• Publication Date: 2019-08-26
• Subjects: channel -- gradient -- growth fault -- lobe -- minibasins -- Niger Delta slope; Geology -- Periodicals; 551
• DOI: 10.1002/gj.3622
• Languages: English
• ISSNs: 0072-1050

Abstract

Abstract : The deep‐water Niger Delta continental slope is a prolific petroleum province. A key challenge in unlocking the potential of such petroleum provinces is in understanding the internal architecture and associated controlling factors of deep‐water depositional systems. Here, we used high‐resolution 3D seismic data to analyse the development of a submarine system on the midslope of the Niger continental margin: the Bakama Submarine Depositional System (BSDS). Over 18 km down dip, the BSDS evolves from lobes through straight channels to lobes again. The fills of intraslope Minibasin I comprised three overlapping lobe complexes varying in size from 1, 200 to 4, 000 m in width, 15 to 30 m in thickness, and 8 to 11 km in length. During the development of these three lobe complexes, Minibasin I and adjacent growth faults interacted with a variety of deep‐water depositional process, which directly influenced the sediment distribution on this slope and the evolution of whole BSDS. Downstream of Minibasin I, ten straight, sub‐parallel adjacent channels occurred on a significantly increased slope (from <2° to >3°). They deeply incise the underlying strata and are small in scale, 150 to 200 m in width, 30 to 45 m in depth with aspect ratios of 4 to 5. On a more gentle slope section (<2°) within the linked downslope intraslope basin (Minibasin II), these adjacent channels are replaced by two attached lobe complexes that are some 2, 100 to 3, 100 m in length, 600 to 1, 700 m in width, and 10 to 30 m in thickness. Therefore, it could be concluded that localized slope gradients play an important role in the development of straight channels and their attached lobes.