Ecca Gr
Type Locality and Naming
Main Karoo Basin (SE), Main Karoo Basin (Western Foredeep), Karasburg Basin, Aranos Basin, Waterberg Basin, Huab Basin, Owambo Basin, Kalahari Basin (SW), Kalahari Basin (Central), Kalahari Basin (NE), Mid-Zambezi Basin, Cabora-Bassa Basin, Main Karoo Basin (Eastern/Northern Forebulge), Springbok Flats Basin, Ellisras Basin, Tshipise Basin, Tuli Basin, Save Basin, Metangula Basin (Mozambique), Ruhuhu Basin (Tanzania), Congo Basin (Lukuga-DR Congo)
Synonym:
Lithology and Thickness
In the type-area of the Main Karoo Basin, Ecca Gr is formally subdivided into Waterford and Fort Brown Fm, Ripon Fm, Collingham and Whitehill Fm and Prince Albert Fm. Transitions from deep marine mudrocks at the base to shallow marine sandstones and coastal swamp/paludal coal measures at the top.
Relationships and Distribution
Lower contact
Typically overlies the glaciogenic deposits of the Dwyka Gr (either conformably or with an unconformity depending on the basin position)
Upper contact
Conformably overlain by the terrestrial fluvial deposits of the Beaufort Gr
Regional extent
Extremely widespread across southern and central Africa, hosting the vast majority of the region's economically viable coal reserves. Regional equivalents include the Mchuchuma Fm, Mbuyura Fm, and Mhukuru Fm (Ruhuhu Basin), Tevrede Fm (Waterberg Basin), and Hammanskraal Fm (Springbok Flats Basin). Kobe Fm, Otshe Fm (Kalahari Basins). Wankie Sandstones, Black Shale & Coal Group, and Lower Madumabisa mudstones (Zambezi/Luangwa)
GeoJSON
Fossils
Contains the aquatic mesosaurid reptile Mesosaurus in the Whitehill Formation and abundant plant flora indicative of a warm, humid climate in the coal-bearing strata.
Age
Depositional setting
The Ecca Gr records the post-glacial flooding of the basins and the eventual transition into shallow marine, deltaic, and coastal swamp environments.
Additional Information
It contains the vast majority of southern and central Africa's economically viable coal measures.