The purpose of this volume is to inform the reader of the detailed geology of the four “divergent margin basins” discussed herein and to establish for the reader a set of analog scenarios which can be used for future petroleum exploration.
The divergent margin basins selected for presentation in this volume by the American Association of Petroleum Geologists are the Campos basin of Brazil, the Gabon basin, the Niger delta, and the basins of the northwest shelf of Australia. These four petroleum basins present a wide range of stratigraphic sequences and structural styles that represent the diverse evolution of this large and important class of world petroleum basins. Members of the AAPG as well as all the government, academic, and company geologists who will benefit from this volume are indebted to the authors, contributing associates, reviewers, and editors of these World Petroleum Basin Series volumes.
All basins in the divergent margin class occur along continental margins near a midplate position, where they overlie and straddle rigid continental and oceanic crust. These basins are now essentially aseismic and non- volcanic. All extant divergent margins are post-Triassic and are related to the sequential breakup of Pangea. They represent the opening ocean portion of the Wilson cycle of earth history (Wilson, 1976). As Pangea split, continental plates moved away from the African center (von Gerhard Bischoff, 1985).
The inboard roots of divergent margin basins lie on attenuated, subsided continental crust beneath the coastal plain, continental shelf, and continental slope. Outboard, they