Otshe Fm
Type Locality and Naming
Kalahari Basin (SW). Southwestern Botswana. Like most Karoo units in Botswana, it is entirely concealed by the Cenozoic sands of the Kalahari Desert and was formally named and defined from extensive borehole core logging by the Botswana Geological Survey.
Synonym:
Lithology and Thickness
A thick, heterogeneous succession of medium to coarse-grained feldspathic sandstones, interbedded with siltstones, carbonaceous mudstones, and prominent, economically significant coal seams.
Relationships and Distribution
Lower contact
Conformably overlies the dark, fine-grained, marine to prodelta carbonaceous shales of the Kobe Fm (Middle Ecca equivalent).
Upper contact
Overlain (often unconformably due to regional intra-Karoo uplift) by the non-carbonaceous, paludal/fluvial mudstones of the Kule Fm (Beaufort Gr equivalent).
Regional extent
Widespread in the subsurface of the Gemsbok Sub-basin in southwestern Botswana and extending towards the Namibian border. Upper Ecca Gr equivalent. It correlates with the coal-bearing upper Ecca units across southern Africa (such as the Waterford Formation in the Main Karoo Basin, or the Boritse Formation in eastern Botswana).
GeoJSON
Fossils
Age
Depositional setting
Fluvio-deltaic and marginal paludal (swamp) environments.
Additional Information