A pair of tortoises retreat into their shells in fear as a couple of geologists appear to study the diamictite they are walking over.
Clasts visible in the rock below mark melting events at the end of the Gondwana glaciation, 300 million years ago. Deposits like these cover much of southern Gondwana, and can be found today in southern Africa, Antarctica, Australia, India and South America. This section is the Dwyka Formation in the Karoo, South Africa.
(c) Geology for Global Development 2013