Fulton's Drift Mudstones Fm
Type Locality and Naming
Tuli Basin and Mazunga Basin (Southern Zimbabwe, near the South African and Botswana borders). Named after Fulton's Drift, a historic causeway and river crossing located in the region. It was formally designated as a distinct lithostratigraphic unit by A.O. Thompson in 1975 to classify the coal-bearing, muddy successions in the Zimbabwean sector of the Tuli Basin (often referred to locally as the Mazunga Basin).
Synonym: Fulton's Drift Formation
Lithology and Thickness
A predominantly fine-grained (clayey) basinal succession. It is composed mainly of grey to black carbonaceous shales and mudstones. Intercalated within these mudrocks are thin, non-economic coal seams and a few discontinuous, lenticular white to light-grey sandstones and pebble beds, which are most frequent near the base of the formation.
Relationships and Distribution
Lower contact
Rests upon basal Karoo glacial deposits (Dwyka Gr equivalents) or rests with a profound unconformity directly upon the ancient Precambrian gneisses and greenstones of the Limpopo Mobile Belt and Zimbabwe Craton.
Upper contact
Conformably overlain by the coarser sandstones and red-bed mudstones of the Upper Karoo sequence (such as the Gushu Fm and Escarpment grit Fm, local Beaufort/Stormberg equivalents).
Regional extent
Restricted geographically to the Zimbabwean portion of the Tuli Karoo Basin (specifically the Mazunga sub-basin) in southern Zimbabwe. Ecca Gr equivalent. In the broader regional context of the Karoo Supergroup, it directly correlates with the Madzaringwe Fm and Mikambeni Fm in the South African portion of the Tuli and Tshipise basins, and the Mofdiahogolo Fm and Sweswe Fm in neighboring Botswana.
GeoJSON
Fossils
Age
Depositional setting
Shallow lacustrine (lake), distal floodplain, and restricted paludal (peat swamp) environments.
Additional Information