Skip to Main Content
Book Chapter

Niger Delta

By
Harry Doust
Harry Doust
Shell International Petroleum Mij. The Hague, Netherlands
Search for other works by this author on:
Ebi Omatsola
Ebi Omatsola
Shell Petroleum Development Co. of Nigeria Ltd. Lagos, Nigeria
Search for other works by this author on:
Published:
January 01, 1989

Abstract

The Niger delta is situated on the Gulf of Guinea on the west coast of central Africa (Figure 1). During the Tertiary it built out into the Atlantic Ocean at the mouth of the Niger-Benue river system, an area of catchment that encompasses more than a million square kilometers of predominantly savannah-covered lowlands. The delta is one of the world’s largest, with the subaerial portion covering about 75,000 km2 and extending more than 300 km from apex to mouth (Figure 1). The regressive wedge of clastic sediments which it comprises is thought to reach a maximum thickness of about 12 km.

Accumulation of marine sediments in the basin probably commenced in Albian time, after the opening of the South Atlantic Ocean between the African and South American continents. True delta development, however, started only in the late Paleocene/Eocene, when sediments began to build out beyond troughs between basement horst blocks at the northern flank of the present delta area. Since then, the delta plain has prograded southward onto oceanic crust, gradually assuming a convex-to-the-sea morphology.

Throughout the geological history of the delta, its structure and stratigraphy have been controlled by the interplay between rates of sediment supply and subsidence. Important influences on sedimentation rate have been eustatic sea-level changes and climatic variations in the hinterland. Subsidence has been controlled largely by initial basement morphology and differential sediment loading on unstable shale. The delta sequence is extensively affected by synsedimentary and postsedimentary normal faults, the most important of which

You do not currently have access to this article.

Figures & Tables

Contents

AAPG Memoir

Divergent/Passive Margin Basins

J. D. Edwards
J. D. Edwards
Retired, Shell Oil Company
Search for other works by this author on:
P. A. Santogrossi
P. A. Santogrossi
Shell Offshore Incorporated
Search for other works by this author on:
American Association of Petroleum Geologists
Volume
48
ISBN electronic:
9781629811307
Publication date:
January 01, 1989

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal