The geology of Lesotho is built on ancient crystalline basement rock up to 3.6 billion years old, belonging to the Kaapvaal Craton, a section of stable primordial crust.
The country is notable for large fossil deposits and intense erosion due to high rainfall and a rare case of southern African glaciation during the last ice age.
[1] Lesotho shares many commonalities with the geology of South Africa, with Kaapvaal Craton crystalline basement rock that formed 3.6 to 2.5 billion years ago.
Geologists have gleaned insights into Lesotho's deep past through extrapolation from South Africa, xenoliths extracted from kimberlite pipes and other data from drilling.
As a result, extreme erosion formed cobble beds with sand and clay layers in lower elevation valleys, with material up to 20 meters thick.
The country has quarrying of Quaternary clay deposits, Drakensberg Group fine-grained basalts and sandstones in the Elliot, Molteno and Clarens Formations.