Late cenozoic shallow marine diamond placers off the northern Sperrgebiet, Namibia

Oelofsen, André

Late cenozoic shallow marine diamond placers off the northern Sperrgebiet, Namibia

Master Thesis

2008

Publisher

University of Cape Town

Department

Department of Geological Sciences

Faculty

Faculty of Science

Abstract

Small scale diver-assisted diamond mining has taken place since 1990 in the shallow marin (<30 m water depth) portions of Mining Licence 45 (Elizabeth Bay) between Halifax Island and Elizabeth Bay along the southwestern coast of Namibia. These operations in the northern part off the coast of the Sperrgebiet have produced almost 400,000 carats over a period of 17 years. Although sparse records remain from the early days, sufficient data from various sources were collected, collated and summarised to make meaningful observations. From historic and current diamond diving records, 4 submarine areas which have yielded high returns were described in terms of their geomorphology, sedimentology and diamond occurrence. Using detailed geophysical survey data (Sidescan Sonar and Multi-beam Bathymetry), the deposition of diamonds at these sites were modelled in GIS-based reconstructions. The diamond size frequency distribution (SFO) of the Shallow Marine (0 to -30 m) deposits in the study area is similar to the proximal aeolian deposit mined on land at Elizabeth Bay and the deeper Midwater (-30 to -70 m depth) deposits situated southwest of the study area.

Description

Includes bibliographical references (leaves 185-193).

Keywords

Geological Sciences

Reference:

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Masters

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