Afri-Can Marine Minerals has completed a marine geophysical survey of the licence area Block J in the ocean off the coast of Namibia. This licence area is located about 140 kilometres north of Luderitz, Namibia.
Block J measures 994 square kilometres, is roughly 50 kilometres long and 20 kilometres wide. It extends between the 70-metre and the 170-metre water depth isobath. Marine & Coastal Geoscience (Pty) Ltd. of South Africa conducted a detailed geophysical survey of the shallowest eastern section of the licence area.
The survey, which began on Jan. 12, was carried out on the prospective shoreward (150 square kilometres) portion, underlain by crystalline bedrock with a cover of thin sediment veneer. This area contains the potential for diamondiferous deposits that match the geological models of the surrounding producing mining licences.
The survey collected 950 line kilometres of high resolution geophysical data. The data interpretation will include an evaluation of depositional environments with potentially diamondiferous sediments and the delineation of sampling targets. Preliminary interpretation of the side-scan sonar and pinger seismic data has identified a number of trap-site features which may have potential for diamond entrapment.
Northern reef: A number of promising features are located in the northeastern corner of the licence area at about 75-metre water depth. This part of the licence is underlain by crystalline basement and already two structurally controlled erosional features have been recognized, which are similar in water depth, size and outline to the Marshall Fork feature presently being mined by Namco and about to be mined by Diamond Fields International. To the north of the concession, Ocean Diamond Mining has mined an area of similar depth.
North of the northern reef: A regionally developed terraced region is found to the north of this reef and extending into block K. Water depth between 75 to 80 metres.
Central reef: Trap sites (gullies and erosional channels) are evident on this reef area which is also covered in places by phoscrete type material.
Southern reef: Also underlain by crystalline bedrock and showing a number of intersecting linear structural-erosional features. Water depth is roughly 100 to 120 metres.
These initial findings are based only on preliminary evaluation of the side-scan sonar and seismic data. Marine & Coastal will complete the bathymetric side-scan sonar and seismic interpretations within the next two months. The next exploration phase planned is a prospecting program of the sampling target features delineated from the geophysical data interpretation. Afri-Can is presently negotiating with different contractors in order to begin the sampling program.
Block J lies on the northern boundary of the known rich diamondiferous deposits currently being mined along the south and central Namibian west coast. To the south of these projects, an inferred resource exceeding 4.25 million carats has been estimated for the region between Halifax and Mercury Islands (Marine & Coastal, June 6, 2000). Block J lies approximately 10 kilometres west of Namco’s Mercury Island mining licence area (ML 36) and is adjoined to the south by Namibian Minerals Corp.’s (Namco) property (EPL 1950), which has a published resource of 653,000 carats (BOE Securities, Oct. 26, 1999).
