Gravity map of Africa - tectonic interpretation

Africa

Dick Gibson's work on Africa was on a proprietary basis for Marathon Oil Company. It utilized the University of Leeds' gravity compilation, together with published geologic and magnetic maps and local proprietary magnetic data. The six-month project resulted in a detailed 21-sheet Interpretation Atlas with clear overlays on the colored gravity maps, together with a 72 page written report.

Much of the gravity data set is of excellent quality for the working scale (1:2,000,000), though there were a few large "holes" and areas of sparse coverage, as in Angola, southern Lybia, and parts of Algeria. This compilation remains the best gravity set for the continent of Africa. Contact GETECH (Univ. of Leeds) for more information about the compilation. Gibson Consulting has no rights to the interpretation Dick Gibson did for Marathon, but you can contact Pat Millegan at Marathon for more information.

Some of the kinds of information contained in this data set are

locations of graben-bounding fault systems and accommodation zones in the Sudan-Anza and East Niger Rifts
basin geometries along the Central African Shear Zone
regional distribution of Karroo Basins and depocenters (for example in Zaire)
probable extensional features in southern Mozambique and Somalia
basement features that may be related to carbonate buildups in the the Sirte Basin
locations of regionally thin crust (with possible thick prospective section)
salt basin geometry in Gabon
basement features of the Benue Trough
subtle structures related to production in the Niger Delta
and many other features useful for basin analysis.

The resolution of the grid is inadequate to map particular grabens and horsts in Cabinda or the Gulf of Suez, but regional basin geometry and accommodation zones can be defined.

This work was done in 1989 and included a 5-year proprietary period for Marathon. Since this period has expired, Dick Gibson is available to work on this data set again. Let us know if you are interested. You might also consider Gibson Consulting's 1- or 2-day program, Architecture of the Continents.

Back to Continent-Scale Page
Back to World Index