Akwokwo Tillite Fm

Period:

Cryogenian

Age Interval:

latest Cryogenian

Province:
Northern Congo Margin

Type Locality and Naming

Lindi Basin of the northeastern DRC.

Synonym: Akwokwo Tillite; depending on the publication, it is also considered to be the basal formation of the Lokoma Gr

Reference: De Wit et al., 2015; Poidevin 2007; Verbeek 1970

[Fig 1. Simplified geological map of the Congo Basin, compiled from various published map. The stratigraphic units have been assembled into major sequences (Late Neoproterozoic, Paleozoic and Cenozoic)]

[Fig 2. Tectonic setting of the Neoproterozoic basins of present-day Central Africa, compiled from the 1: 2M geological map of the Zaire (Lepersonne, 1974) and the 1: 4M map Geology and Major Ore Deposits of Africa (Milesi et al., 2006)]

[Fig 3. Lithostratigraphic synthesis for the Neoproterozoic to Early Paleozoic period. Compiled after various authors. Dotted lines between Banalia, Alolo and Galamboge formations: stratigraphic transition by recurrences]

[Fig 4. Lithostratigraphic columns for the Congo Basin established using data from the 4 wells in the central part of the basin and outcrops on its NE margin (Lindi-Ubangi and Kisangani-Kindu region), compared with the West-Congo and Katanga stratigraphy]

[Fig 5.Simplified geological map of Sub-Saharan Africa showing the Neoproterozoic basins on and around the Congo Shield (modified after De Waele et al. 2008). (LC) Lower Congo Basin, (Co) Comba Basin, (Sa) Sangha Basin, (Ny) Nyanga-Niari Basin, (An) Angola Basin, (SO) Semb-Ouesso Basin, (Ba) Ubangui Basin, (LiB) Likki-Bembe´ Basin, (Bk) Bakouma Basin, (Fou) Fouroumbala Basin, (Li) Lindi Basin, It Itombwe Basin, (Ma)Malagarazi-Bukoban Basin, (Mb) Sankuru-Mbuji-Mayi-Lomami-Lovoy Basin, (Lu) Luamba Group, (Kat) Katanga Basin, (RB) Ruwenzorian Belt, KaB) Karagwe-Ankole Belt, (RuB) Ruzisian Belt, (KiB) Kibaran Belt,(UB) Ubendian Belt, IB Irumide Belt]

[Fig 6. Northern margin of the Congo Shield. (A) Geological sketch map of the Lindi Basin (modified after Verbeek 1970; Poidevin 1985)]

[Fig 7. Stratigraphic logs of the Lindi Supergoup in the DRC (modified after Verbeek 1970). (C and D) Stratigraphic logs of the Lindi Supergoup in CAR (modified after Poidevin 1985). cc cap carbonates, SG Sturtian Glaciation, MG Marinoan Glaciation]

[Fig 8. Stratigraphic correlation between the Neoproterozoic sedimentary basins in Central Africa. Correlations based on Sr isotopic data, radiometric age constraints and revised lithological relationships]

Lithology and Thickness

The 40-m-thick Akwokwo Tillite is equivalent to the Upper Diamictite of the West Congo Margin basins.

Lithology Pattern:

Glacial till

Relationships and Distribution

Lower contact

Lies on the Ituri Gr

Upper contact

Capped locally by carbonaceous argillites interbedded of cap carbonate lenses at the base of the Lokoma Gr

Regional extent

Extend in the Lindi Basin of the northeastern DRC. Trompette (1994) considered this basin and Fouroumbala-Bakouma basins of the south-western CAR, and to be part of the Lindi Basin.

GeoJSON

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Fossils

Age

Marinoan glaciation of latest Cryogenian

Age Span:

Beginning stage:

Cryogenian

Fraction up in beginning stage:

0.9

Beginning date (Ma):

643.50

Ending stage:

Cryogenian

Fraction up in the ending stage:

1.0

Ending date (Ma):

635.00

Depositional setting

Glacial deposits

Depositional pattern:

Additional Information

Compiler:

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

Geology and Resource Potential of the Congo Basin by Maarten J. de Wit, François Guillocheau and Michiel C.J. de Wit , Published Springer-Verlag Berlin Heidelberg 2015; DOI 10.1007/978-3-642-29482-2

Kadima, E., Delvaux, D., Sebagenzi, S.N., Tack, L., Kabeyaz (2011). Structure and geological history of the Congo Basin: an integrated interpretation of gravity, magnetic and reflection seismic data Basin Research (2011) 23, 499–527, doi: 10.1111/j.1365-2117.2011.00500.x