Mosso Gr

Cenozoic

Mesozoic

Paleozoic

Neoproterozoic

Paleoproterozoic

Mosso Gr

Period:

Tonian

Age Interval:

Tonian

Province:
Eastern Congo Margin

Type Locality and Naming

The Malagarazi-Bukoban Basin (Burundi-Tanzania) is located along the boundary between the Archean Tanzania Craton to the east, the Mesoproterozoic Karagwe-Ankole Belt to the west and the Paleoproterozoic Ubendian Belt to the south. Lithostratigraphically, the Malagarazi Supergroup, stratigraphic-equivalent to the Bukoban Supergroup of Tanzania, is divided from base to top into Musindozi Gr, Mosso Gr and Kibago Gr (Tack 1995).

Synonym:

Reference: De Paepe et al. 1991; Tack 1995; de Wit et al., 2015

[Fig 1. Lithostratigraphic synthesis for the Neoproterozoic to Early Paleozoic period. Compiled after various authors (see text).Dotted lines between Banalia, Alolo and Galamboge formations: stratigraphic transition by recurrences.]

[Fig 2. 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. 3.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. 4. Stratigraphic correlation between the Neoproterozoic sedimentary basins in Central Africa. Correlations based on Sr isotopic data, radiometric age constraints and revised lithological relationships (de Wit et al., 2015).]

Lithology and Thickness

Consists of the approximately 150 m-thick siliciclastic and carbonate in the Mosso Group including 100 m-thick amygdaloidal basalts at 815 +/- 14 Ma (De Paepe et al. 1991).

Lithology Pattern:

Sandy limestone

Relationships and Distribution

Lower contact

Rests on the Mosindozi Gr

Upper contact

Overlain by the Kibago Gr

Regional extent

Neoproterozoic sedimentary rocks exposed on the eastern CS basins (Malagarazi-Bukoban Basin) in the DRC and Burundi-Tanzania successively

GeoJSON

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Fossils

Age

If similar to West Congo Margin basins as shown in the basin-correlation diagram in de Wit et al. (2015), this Gr spans ca. 70% to 85% up in Tonian; but base put at 65% to account for the ca. 815 Ma age of the basalts.

Age Span:

Beginning stage:

Tonian

Fraction up in beginning stage:

0.65

Beginning date (Ma):

818.00

Ending stage:

Tonian

Fraction up in the ending stage:

0.85

Ending date (Ma):

762.00

Depositional setting

The Malagarazi-Bukoban Supergroup are unmetamorphosed (Tack 1995). Deformation in the Itombwe and Malagarazi-Bukoban basins may be kinematically linked with strike-slip reactivation of the Kibaran and Karangwe-Ankole belts and/or Ubendian Belt during Pan-African orogen (de Wit et al., 2015).

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

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