Late last year I visited the Waterberg area of South Africa. I was standing on a ridge overlooking a thunderstorm moving over a distant plain. The pictures above show the progression of the storm over about a half hour. The area is pristine and typical of the Waterberg area with thorn trees and low lying hills. I imagined that this scene would have been been witnessed by Australopithecus africanus or Homo Erectus as they looked over a similar landscape millions of years ago.
The hills in the distance are 1.6 billion year old sedimentary rocks called the Waterberg Supergroup rocks which are a sequence of conglomerates, sandstones and shales. Read more on the Waterberg rocks at http://www.onlineminerals.com/geo.htm