Cenozoic

Mesozoic

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El Azaza Formation

El Azaza Fm

Period:

Jurassic

Age Interval:

Late Jurassic

Province:
Sudan E

Type Locality and Naming

Khartoum Basin, central Sudan. Type well AAF-1, where the thickness if 36 m (10593 ft – 10712 ft).

Synonym: Azaza 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)]

Lithology and Thickness

"Azaza is the oldest Mesozoic formation reached by boreholes in the Khartoum Basin. The formation consists predominantly of ophitic and porphyritic extrusive basalt (Sim Oil, unpubl. rep.) alternating with thin red claystones and coarse sand in places." (Awad, 1994) The formation is 576 m thick in the AAF-2 well.

Lithology Pattern:

Lava

Relationships and Distribution

Lower contact

Major unconformity onto "Silurian Basalt" unit of uncertain actual age span

Upper contact

Overlain by the Abu Jinn Fm; although A. Gibreel (Ministry of Petroleum and Gas, 2015) notes that the contact is poorly dated and the Tithonian might be Abu Jinn Fm.

Regional extent

Khartoum Basin, central Sudan.

GeoJSON

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Fossils

Spores (Dictyophyllidites harrisii, Verrucösisporites sp. A, Todisporites minor). Pollen (Alisporites sp. C, Ginkgocycadopites sp. B, Callialasporites sp. A, Inaperturopollenites orbiculatus, Exesipollenites tumulus, Callialasporites trilobatus), Freshwater alga (Leisphaeridia sp., Celyphus rallusl) (Awad, 1994)

Age

Oxfordian-Tithonian according to A. Gibreel (Ministry of Petroleum and Gas, 2015); although he notes that the Tithonian might be Abu Jinn Fm (poorly dated contact).

Age Span:

Beginning stage:

Oxfordian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

161.53

Ending stage:

Tithonian

Fraction up in the ending stage:

1.0

Ending date (Ma):

143.10

Depositional setting

Fluvial to lacusrine

Depositional pattern:

Additional Information

Compiler:

Enam O. Obiosio, Solomon Joshua Avong and Henry Nasir Suleiman (2024) - Stratigraphic Lexicon compiled from the following publications:

Awad, M.Z., 1994. Stratigraphic, Palynological and Paleoecological Studies in the East-Central Sudan (Khartoum and Kosti Basins), Late Jurassic to Mid-Tertiary. Berliner Geowiss. Abh. 161: 163 pp.

Gibreel, Ahmed (Section Head G&G Studies, Ministry of Petroleum and Gas, Republic of Sudan(, 2015. Hydrocarbon potential and resources in Sudan. [Slide presentation at UNCTAD, 17^th Africa OILGASMINE, Khartoum, 23-26 Nov 2015]. https://unctad.org/system/files/non-official-document/17OILGASMINE%20Ahmed%20Gibreel%20Ahmed%20El-Amain%20S1.pdf