Abu Jinn Fm

Khartoum Basin, central Sudan. Type well is AAF-1, where it is 271 m thick.

Synonym: Abu Gin Fm (as used by Awad, 1994)

Reference: Awad (1994), A. Gibreel (2015)

[Fig. 1: Khartoum Basin is #8 on map (Fig.3 in Awad, 1994)]

[Fig. 2: Khartoum Basin stratigraphy and depositional sequences (pg. 17 in A. Gibreel, 2015)]

"At the type section, the Abu Gin contains predominantly grey claystones and shales interbedded with thin siltstones, sandstones, and volcanics near the top of the formation. Shales are dark grey to greenish grey and fissile. Siltstones are dark grey and moderately indurated. Sandstones occur only sporadically. They are fine- to medium-grained and are generally recovered as disaggregated grains. The grains are clear to translucent and angular in shape. Aggregates are possibly cemented by kaolinitic and argillaceous materials. In general, the whole formation becomes more tuffaceous towards the top. Unlike in the type well and in AAF-4, the top unit of the Abu Gin in AAF-2 is lithologically characterized by an upward passage from a sequence of interbedded claystone, siltstone and volcanics to a predominantly sandy sequence. This sandy sequence occurs between 1772 m (5815 ft) and 1664 m (5460 ft) depth and comprises coarsening upward argillaceous sandstones that alternate with carbonaceous claystones." (Awad, 1994)