Articles

Jako Schonken

I arrived at OR Tambo airport on a cold winter’s Thursday morning, hoping it wouldn’t rain. I hired a car and started driving in a northerly direction, following my GPS to Marble Hall - a place I have only heard about in the South African Micromount Society’s newsletters. I have been a member of the South African Micromount Society (SAMS) for more than three years, but have never been to their meetings or outings since they are based in Gauteng. Nor have I ever met any of the members, although we often e-mail back and forth. When I received the bulletin that they are planning a field trip to the Stavoren mine over the long weekend, I decided to bite the bullet, buy a plane ticket, arrange for a car, and book a room at a nearby guest farm.

I met Kevin Hean, one of the SAMS members outside OK Foods in Marble Hall and followed him to his accommodation. We headed off to the mine in his Toyota Prado, him laughing when I told him I wanted to drive to the mine with my hired Kia Picanto.

The Stavoren Mutue-Fides tin fields are located approximately 20 km to the north of Marble Hall. A gravel road takes you past the Arabie dam to another gravel road which gradually gets worse as you approach the mine. The land is currently owned by a local chief and remains unused except for the few locals that cut wood there. The tin field consists of a group of shafts and tailings scattered over a large area.

Records show that the area was prospected for tin since the beginning of the 20^th century, shortly after the Anglo-Boer War; however at the time it was considered not economically viable. The discovery of alluvial cassiterite in 1912 led to more prospecting and as a result the deposits on the farms of Stavoren, Mutue-Fides, Gaasterland and Roodewal were discovered. The farm Stavoren was worked for tin, tungsten and copper by the Stavoren Tin Mining Co. in 1919 and later by the Zaaiplaats Tin Mining Co. in 1920. Only moderate quantities of ore at relatively shallow depths were ever discovered and no mining has been undertaken since. From time to time the deposits have been re-evaluated, depending on the fluctuating metal prices.^1.

We followed the GPS co-ordinates that Stephen Gomersall, the SAMS newsletter editor, provided and, after about half an hour’s bumpy tweespoor track, and having made a wrong turn somewhere, we met the party at Hillside Quarry.

Micro mineral collecting differs from conventional mineral collecting in that you can choose a good spot on a tailings pile, sit down and screen the material around you by breaking the rocks until you find one that looks like it has potential. A 10× loupe is key for confirming if your material indeed has some micro crystals. The material with potential is taken home, inspected under a microscope and trimmed further as required. The resulting specimen will then be mounted in a small box to protect the crystals from damage and labeled/ cataloged. 

Though most of the SAMS members only came through for the day, Kevin, Henk and I decided to spend the Friday inspecting the other sites for potential, even though it was reported that the Hillside Quarry was by far the best collecting spot. B-line working was first on the list. These were the most extensive workings with smelters, built structures and an intact adit still to be seen. I found a very nice scheelite crystal in matrix here after spending some time breaking rocks with a sledgehammer. We moved on to find Spruit Workings and Western Quarry. We spent a considerable amount of time looking for these two spots. I decided to recce the area on foot while Henk and Kevin stayed behind at Gaasterland, another collecting spot. I did manage to find Spruit, but a barbed wire fence was put up across the tweespoor track, so I collected what I could and headed back to Gaasterland where we put together all we had found and called it a day.

While I collected more than 30 kg of specimens, I only brought back a handful on the flight. Needless to say, I’m excited to see what I’m going to find once I receive the rest!

^1. [Atanasova, M., Cairncross, B. and Windisch, W.R. (2016) Microminerals of the Bushveld Complex, South Africa. Popular Geoscience Series 6, Council for Geoscience, Pretoria, South Africa]