Prince Albert Fm
Type Locality and Naming
Main Karoo Basin (SE), Main Karoo Basin (Western Foredeep) South Africa, Aranos Basin, Owambo Basin. Lowermost formation in Ecca Gr
Synonym:
Lithology and Thickness
Deep marine mudstones. Prince Albert Fm (in Namibian stratigraphy) is divided into Rietmond Shale Member, Auob Sandstone Member, Mukorob Shale Member, and Nossob Sandstone Member are part of the geology of the Aranos Basin (specifically in the Stampriet Artesian Basin region) in southeastern Namibia.
From top (youngest) to bottom (oldest), the sequence within the Prince Albert Formation in this region is: Rietmond Member (Shale and sandstone), the uppermost unit, which acts as the upper confining layer (aquiclude) for the underlying Auob aquifer. It is highly variable in thickness due to pre-Kalahari erosion. Auob Member (Sandstone), directly underlies the Rietmond Member. It is a major, porous, multi-story channel sandstone unit that forms one of the most critical artesian aquifers in Namibia (the Auob Aquifer). Mukorob Member (Shale/Mudstone), sits below the Auob Member and above the Nossob Member. This is a pelitic (shale, mudstone, and siltstone) succession deposited in a shelf setting. Nossob Member (Sandstone), the basal member of this sequence. It consists of medium to coarse-grained sandstones (interpreted as a prograding delta-front) and sits unconformably on the glacial deposits of the underlying Dwyka Gr (Kameelhaar Mbr). It forms the lower artesian aquifer in the basin.
Relationships and Distribution
Lower contact
Typically overlies the glaciogenic diamictites and tillites of the underlying Dwyka Gr
Upper contact
Conformably overlain by the black, carbonaceous mudstones of the Whitehill Fm
Regional extent
Main Karoo Basin, South Africa. Catuneanu et al. (2005) mentions the Aranos Basin and the Prince Albert Formation broadly in their correlation charts (e.g., Figure 3)
GeoJSON
Fossils
Age
Depositional setting
Deep marine environments; represents post-glacial flooding and suspension settling in an interior seaway during the "early underfilled" stage of the Karoo retroarc foreland basin (Figure 2).
Additional Information
The Prince Albert Formation records the immediate marine transgression that followed the retreat and melting of the Dwyka ice sheets across the basin.