Introduction
The community of KwaMachi purported to have discovered gold in a quarry near Harding. The Council for Geoscience (CGS) was then requested by the Minister of Mineral Resources to investigate the veracity of the purports of gold in the KwaMachi region, which is part of the uMziwabantu Municipality in the KwaZulu Natal Province. In June 2018, the CGS conducted investigations in the Harding quarry where the aggregate was mined to maintain local roads and where the local community claimed to have found a gold deposit. In the first investigation, rock samples were collected from the quarry and analysed at the MINTEK Laboratory in Johannesburg. The 150 m by 150 m quarry was used primarily as a source of aggregates for improving the condition of the local roads. Although the first set of results showed that the quarry did not contain gold, The CGS decided to conduct further investigations.
Pending geological evidence of the purported gold, the quarry was closed to allow the CGS to conduct a second investigation which was conducted in October 2018. The sample area was widened to include the quarry and its surroundings. This will allow for a comprehensive conclusion on the accuracy of the claims of the community on the presence of gold in the Harding area. In this phase, the CGS collected rock (21) and soil samples (98). Although the known gold deposits in the KwaZulu-Natal Province are associated with heavy minerals and quartz veins in sandstones and are much further away from the Harding area. The geology of the Harding areas, which is mostly of the Karoo Supergroup (shale and dolerite – Figure 1), is not a suitable geological setting for gold. The second investigation of the CGS corroborated this.
The laboratory results found that the gold, platinum or palladium in the quarry and its surroundings is at the background level, meaning not economically mineralised. Mineral sulphides such as pyrite, chalcopyrite, pentlandite, cobalite, sphalerite and galena occur in the quarry. Pyrite and chalcopyrite have similar appearances to gold and can easily be mistaken for this precious metal.
Based on the analytical data presented in this report, the following conclusions can be made:
There is no economic gold, both in the quarry and its surroundings. All concentrations are significantly low and are within normal values in the rocks.