Southern orange free state (SOFS) is situated in the Magisterial District Matjhabeng, near the towns of Welkom, Virginia and Theunissen, approximately 240km south-west of Johannesburg, in the Free State province of South Africa. The site is adjacent to Beatrix, and is accessed via the N1 highway between Johannesburg and Kroonstad and then via the R30. Geologically, it is located in the Free State Goldfield and will form part of the southernmost gold mine in the Witwatersrand Basin. The SOFS area includes: Wits Gold prospecting areas comprising the Bloemhoek and De Bron Merriespruit projects, which are separated by regional faulting.
SOFS, in its current form, dates from April 2014 when Sibanye-Stillwater acquired Wits Gold. Sibanye-Stillwater is investigating the possibility of submitting a Section 102 application seeking consent from the Department of Mineral Resources to amend the Beatrix Mining Right by consolidating the Beatrix Mining Right, SOFS Mining Right and Prospecting Rights. Bloemhoek and De Bron Merriespruit are exploration projects and a c has been completed for De Bron Merriespruit but as yet no mining activities have been initiated. Historically, a total of 99 boreholes were drilled in the De Bron Merriespruit project area and estimation is in line with Sibanye-Stillwater standards and protocols. From 1947 to 2004, a total of 28 surface boreholes were drilled in the Bloemhoek project area. Most of this drilling was completed by Anglo American during the 1980s. Wits Gold acquired the property and data in 2004 and subsequently drilled a further four boreholes which culminated in a pre-feasibility study, completed in 2009, with a SAMREC Code (The South African Code for the Reporting of
the Exploration Results, Mineral Resources and Mineral Reserves) compliant Mineral Resource and Mineral Reserve Statement. Since then, two more exploration boreholes were drilled in 2017 to firm up the Mineral Resource model in the Bloemhoek area, north of the 3 Shaft complex decline extention. Beisa North has been proven to not be economically attractive at present. The prospecting right has lapsed. Subsequently, it has been decided to apply for further prospecting rights for the Beisa North area.
Mode of occurrence
Laterally continuous with mid-range predictability. Shallow gold/uranium deposits comprising the BXR/VS5, AAR, B and Leader reefs of the Central. Rand Group of the Witwatersrand Supergroup. Clear patterns of mineralisation characterised by a highly channelised fluvial depositional environment. The Beisa Reef was predominantly mined for its uraniferous content at the old Beisa uranium mine located within the Beatrix Mining Right.
Notes on Mineral Resource Statement
Geostatistically estimated density is used. A provisional mine design at De Bron Merriespruit project caters for a standard Witwatersrand gold mine design accessing underground orebody via a vertical and decline shaft system and utilising conventional scattered breast mining methods. Sibanye-Stillwater intends to combine the Beatrix and SOFS Mining Right within the greater Free State Mining Right. The Bloemhoek project constitutes the western extent of the SOFS Mining Right, covering an area of approximately 4,060 ha. The current life of mining for De Bron Merriespruit is estimated at 19 years. The De Bron Merriespruit project is the only SOFS project that was subjected to a feasibility study.