EXPLORATION IN THE OKIEP-COPPER-DISTRICT, NORTHERN CAPE PROVINCE, SOUTH-AFRICA - AN OVERVIEW

The Okiep Copper District, covering 3000 km(2), is situated in the Pro terozoic Namaqualand Metamorphic Complex. A swarm of easterly-trending , intermediate to basic bodies, collectively termed the Koperberg Suit e, intrudes the granulite facies granite-gneiss terrane. The bodies di splay a wide range of emplacement modes and geometries including dyke- , plug-, and sill-like forms. Copper mineralization occurs as fine dis seminations and local massive concentrations of sulphides associated w ith the more basic members of the suite. Disposition of ore bodies bro adly correlates with major lithological contacts. Exploration techniqu es employed in a previous exploration cycle (1946-1984) included regio nal and detailed geological mapping and geophysical surveying utilizin g magnetic, gravimetric, and electrical methods. The current explorati on programme (since 1988) employs a multidisciplinary approach in whic h results from research projects, advanced geophysical techniques, and previous exploration activities are being incorporated in systematic prioritization of drill targets. Despite modern advances in both geolo gy and geophysics, diamond drilling remains the definitive proof of th e presence of an ore body, and the current level of surface drilling i s in the order of 16 000 m per annum.