Biano Gr

Cenozoic

Mesozoic

Paleozoic

Neoproterozoic

Paleoproterozoic

Biano Gr

Period:

Ordovician, Silurian, Devonian

Age Interval:

uncertain Ordovician-Devonian

Province:
Southern Congo Margin

Type Locality and Naming

Katanga Basin, Southern Congo margin in DRC and Zambia

Synonym:

Reference: Brock 1961; Cailteux et al. 2007; de Wit and Linol 2014; Fernandez-Alonso et al. 2012;Kampunzu and Cailteux 1999; Tait et al. 2011; Steven 2000

[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, 1974a) and the 1: 4MmapGeology 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 (see text).Dotted lines between Banalia, Aloloand 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: Southern margin of the Congo Shield. (A) Geological sketch map of the Katanga Basin (modified after Heijlen et al. 2008). (B) Synthetic stratigraphic log combined with C and Sr isotopic curves of the Katanga Supergroup in the DRC and Zambia (modified after d ‰13 Cailteux et al. 2005). Note the declines in C estimated at 6.7 in d 1 the Lower Roan Group, followed by intervals with strong 3C enrichments, attributed to the Bitter Spring negative excursion and a d1 second negative 3C shift at the top of the Mwashia Group, reported to the Sturtian glacial events (Bull et al. 2011)]

[Fig 7: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

Consists of siliciclastic rocks made up of sandstone, quartzite and conglomerate and having thickness of about 1400m. These sequences stretching over a 700 km-long and 50 km-wide region from the Mwinilunga district in northwestern Zambia (Brock 1961; Steven 2000), east-northeastwards through Kolwezi and Likasi (DRC), and southeastwards to Bwana Mkubwa (Zambia) and Lonshi (Cailteux et al. 2007).

Lithology Pattern:

Coarse-grained sandstone

Relationships and Distribution

Lower contact

Lies unconformably on the Ngule Subgroup of the Kundelungu Gr of the Katanga Super Gr

Upper contact

Overlain by Karoo Super Gr (Lukuga Gr of glacial till?)

Regional extent

Katanga Basin, Southern Congo margin in DRC and Zambia. Exposed in the Mwinilunga district in northwestern Zambia, east northeastwards through Kolwezi and Likasi (DRC), and southeastwards to Bwana Mkubwa (Zambia) and Lonshi

GeoJSON

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Fossils

Age

Assuming equivalence to Inkisi Gr, then ca. Ordov-Devon interval

Age Span:

Beginning stage:

Tremadocian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

486.85

Ending stage:

Tournaisian

Fraction up in the ending stage:

0.0

Ending date (Ma):

359.30

Depositional setting

Inkisi Gr and Biano Gr are considered to be red-bed sequences of post-Pan African and pre-Karoo age (Tait et al. 2011; de Wit and Linol 2014).

Depositional pattern:

Additional Information

These sequences are affected by the Pan-African or Lufilian north-directed folding and thrusting deformations (620–570 Ma; Kampunzu and Cailteux 1999). Since the Mesoproterozoic Eon, the CS region was subjected to intermittent episodes of extensional activity resulting in long-lived shallow cratonic basins, which were subsequently deformed by short-lived phases of compression during the Neoproterozoic (Fernandez-Alonso et al., 2012).

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