Mchuchuma Fm
Type Locality and Naming
Ruhuhu Basin (Tanzania). Named after the Mchuchuma River in the Ruhuhu Basin of southwestern Tanzania. Originally mapped and described by Stockley (1932) as the "K2" horizon or the "Lower Coal Measures." It was formally designated as the Mchuchuma Formation within the modern Songea Group lithostratigraphy by later authors (e.g., Wopfner, 2002). Lower formation in Ecca Gr in Ruhuhu Basin (Tanzania)
Synonym: K2 Beds / Lower Coal Measures
Lithology and Thickness
Composed of a cyclic fluvio-deltaic and paludal sequence. It typically consists of thick, cross-bedded, coarse-grained arkosic sandstones interbedded with carbonaceous shales, siltstones, and economically significant, thick, workable coal seams.
Relationships and Distribution
Lower contact
Conformably to transitionally overlies the basal glacial and periglacial deposits of the Idusi Fm (K1).
Upper contact
Unconformably or disconformably overlain by the coarse clastics and red beds of the Mbuyura Fm (K3).
Regional extent
Widespread within the Ruhuhu Basin and extending into other Karoo-aged grabens in southwestern Tanzania (e.g., the Ketewaka-Mchuchuma Coalfield). It is a direct regional equivalent of the Vryheid Fm (Ecca Gr) in the Main Karoo Basin of South Africa, the Luwumbu Coal Fm in Zambia, and the Fubue Fm/Congresso Fm in Mozambique.
GeoJSON
Fossils
Age
Depositional setting
Fluvial, deltaic, and extensive paludal (swamp) environments within an actively subsiding intracratonic rift basin.
Additional Information