The Ganigobis Formation is a Late Carboniferous (Gzhelian) to Early Permian (Artinskian) geologic formation of the Dwyka Group in the ǁKaras Region of southeastern Namibia and the Northern Cape of South Africa. The widespread formation was deposited in the Aranos and Karoo Basins of southern Africa.
Description The Ganigobis Formation is an extensive unit with a maximum thickness of evidenced in the Vreda borehole.Bangert et al., 2000, p.266 The conglomerates, sandstones, shales and tuff of the formation were deposited in a glacio-lacustrine to marine environment.Ganigobis Formation at Fossilworks.orgBangert, 2000, p.21 The Ganigobis Formation provides fossil fish as well as bivalves (e.g. Nuculopsis), gastropods (e.g. Peruvispira), scyphozoa (e.g. Conularia), crinoid stalks, foraminifera (Hyperammina, Ammodiscus, Glomospira, Ammobacculites and Spiroplectammina),Bangert, 2000, p.60 sponges and sponge spicules, radiolaria, coprolites and permineralised wood.Bangert, 2000, p.3
Zircons of the Ganigobis Shale Member yield SHRIMP-ages of 302-300 Ma. This dates the uppermost part of the second deglaciation sequence in southern Namibia to the Late Carboniferous (Gzelian) and provides a minimum age for the onset of Karoo-equivalent marine deposition. The age of the uppermost argillaceous part of the third deglaciation sequence (297 Ma) was determined from zircons of a tuffaceous bed sampled in a roadcut in the Western Cape Province, South Africa.
Fossil content Among others, the following fish fossils are reported from the formation:Ganigobis at Fossilworks.orgWesselton Mine, Kimberley at Fossilworks.orgGanigobis, near Tses Station at Fossilworks.org
Acrolepis addamsi Namaichthys schroederi Watsonichthys lotzi
See also List of fossiliferous stratigraphic units in Namibia List of fossiliferous stratigraphic units in South Africa Geology of Namibia Geology of South Africa Irati Formation
References
Bibliography
Further reading B. G. Gardiner. 1962. Namaichthys schroederi Gürich and other Palaeozoic Fishes from South Africa. Palaeontology 5(1):9-21