10 March 2017
Friday fold: Sheba Mine sample
Posted by Callan Bentley
When touring the geology of the Barberton Greenstone Belt last August, our group visited the Sheba Mine, a gold mine high in the hills. Their geologist kindly showed us around and allowed us to visit his history-laden office. I have no idea where this sample originated, but it was the only fold I saw in the place, nestled between sepia-toned photographs and old lanterns and rusty picks.
I wonder what the layers would have done if there was more to the sample at the bottom edge. Given the way they inflect inward on each limb, it’s a curious shape for a fold.
It is likely a folded banded iron formation – with alternate iron-oxide and chert layers. If you take one of those smaller diversions from the main Barberton-Swaziland road, there are some spectacular folded BIF outcrops – known to many of those hard-core “students” of BIF. By the way, the clarify of your photos in the blog are superb… Mpho (Botswana)