Escarpment Grit | |
---|---|
Stratigraphic range: Early Triassic | |
Type | Geological formation |
Unit of | Upper Karoo Group, Karoo Supergroup |
Underlies | Pebbly Arkose Formation |
Overlies | Lower Karoo Group |
Lithology | |
Primary | Gritstone |
Other | Sandstone |
Location | |
Country | Zambia Zimbabwe |
Type section | |
Named for | Descriptive name |
Named by | A.M. MacGregor, Zimbabwe Geological Survey |
The Escarpment Grit is a Triassic geologic formation.[1] It is also referred to as the Nyoka Grit.[2]
The formation is composed of fluvial sediments, mainly gritstones and coarse sandstones.[3] Uranium is present in the Escarpment Grit of southern Zambia.[4]
The Escarpment Grit Formation is the basal unit of the Upper Karoo Group[5] and underlies the Pebbly Arkose Formation.[6] It has been dated as Upper Scythian (Early Triassic).[7]
The Pebbly Arkose has been correlated to the Angwa Sandstone Formation in the Mana Pools and Cabora Bassa Basins,[8] and the Elliot Formation of the Great Karoo Basin, South Africa.[6][7]
Alisporites spores have been identified from the Escarpment Grit in north-western Zimbabwe.[8]
This formation constitutes a productive aquifer in north-western Zimbabwe, although of limited thickness.[9]