Adok Fm

Muglad Basin -- SW Sudan and the northwestern part of South Sudan. Upper-middle formation of the Kordofan Gr

Reference: Babikir, 1997; Makeen et al., 2013; Jingyao, 2015

[Fig. 1: Western and Central African rift system. West African rift subsystem and Central African]

[Fig. 2: General stratigraphic column - Muglad Basin, Sudan, showing three geological cycles – Neocomian to Barremian, Aptian to Maastrichtian, and Paleocene to Pliocene - Miocene, or Quaternary and Petroleum Systems (from Ahmed and Ozumba, 2017)]

[Fig. 3: Comprehensive stratigraphic columns in the Muglad Basin (from Dou et al., 2023)]

[Fig. 4: Regional stratigraphy of the Muglad basin, SW Sudan (after Schull 1988; Dou Lirong et al. 2013 – extracted from Makeen et al., 2013)]

[Fig. 5: Location map of the Fula sub-basin in the Muglad basin including oilfields (study area) (after Dou Lirong et al. 2013 – extracted from Makeen et al., 2013)]

This formation consists of predominantly massive beds of grey, yellow, orange and brown clay, with thin locally developed beds of fine-grained sand, soft clays and consolidated claystones. Clay ironstone and iron staining are locally common (Babikir, 1997). The Adok Formation is made up of coarse-grained sandstones and has an estimated thickness of 1000m (Makeen et al., 2013; Jingyao, 2015).

Pollens (Verrucato-sporites spp.)

Late Miocene-Pliocene

The predominantly argillaceous nature of the sediments indicates a low energy depositional environment of shallow oxic lakes (Babikir, 1997).