Cenozoic

Mesozoic

Information provided by geoscience team at Ahmadu Bello University, Zaria, Nigeria --see About

Maikona Formation

Maikona Fm

Period:

Paleogene

Age Interval:

Paleocene-Oligocene

Province:
Kenya

Type Locality and Naming

The Anza Basin of north-central Kenya is ca. 560 km long and appears to be deepest towards its northeast side, where the rift spans 130 km. The available information on the Anza basin is largely based on well data from five wells drilled by Amoco Kenya and Total Kenya in the late 1980s (Winn Jr et al., 1993). Stratigraphic subdivision of its sedimentary infill into groups and formations is yet to be completed (Lenhardt et al., 2025).

Synonym:

References: Reeves et al., 1987; Bosworth, 1992; Winn Jr et al., 1993; Lenhardt et al., 2025

[Fig. 1: Stratigraphy of the CARS (modified from Schull, 1988; McHargue et al., 1992; Guiraud and Bosworth, 1997; Gani et al., 2009; Wolela, 2009; Dou et al., 2013, 2018, 2023a; Liu and Chen, 2014; Eisawi et al., 2015; Mohammed et al., 2016; Bussert et al., 2018; Yassin et al., 2017; Mohammed Yasin et al., 2019; Gao et al., 2023)]

[Fig. 2: Simplified map of the West and Central African Rift System (WCARS) showing the Anza Basin in Kenya (modified from Genik, 1993).]

Lithology and Thickness

The Maikona Fm is made up of fluvial sandstones (Fig. 9 of Lenhardt et al., 2025)

Lithology Pattern:

Sandstone

Relationships and Distribution

Lower contact

AnzaCret Sandstone-Shale Fm, unconformably (uppermost Maastrichtian is absent) (Fig. 9 of Lenhardt et al., 2025)

Upper contact

AnzaVolcanic-Alluvial Fm, unconformably?

Regional extent

Anza Basin

GeoJSON

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Fossils

Age

Age Span:

Beginning stage:

Danian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

66.04

Ending stage:

Chattian

Fraction up in the ending stage:

1.0

Ending date (Ma):

23.04

Depositional setting

fluvial (Lenhardt et al., 2025)

Depositional pattern:

Additional Information

Compiler:

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

Lenhardt, N., Omietimi, E. J., Edegbai, A. J., Schwark, L., Catuneanu, O., Fairhead, J. D., Gotz, A. E. (2025): Traversing the rift: A review of the evolution of the West and Central African Rift System and its economic potential. Earth-Science Reviews, 261: pp. 1-39