Upper Wankie Sandstone Fm
Type Locality and Naming
Mid-Zambezi Basin (Zimbabwe and southern Zambia). Named after the Hwange (formerly Wankie) district in northwestern Zimbabwe. It was formally defined by early 20th-century geologists mapping the region's vast coalfields, named for its distinct stratigraphic position lying immediately above the main economic coal seams. Upper formation in Ecca Gr in Mid-Zambezi Basin
Synonym:
Lithology and Thickness
Predominantly a massive, high-energy arenaceous (sandy) succession. It consists of coarse-grained, strongly cross-bedded, white to pale grey feldspathic sandstones (arkose). It is highly micaceous and frequently contains thin lenticular bands of carbonaceous shale, occasional thin coal stringers, and localized basal conglomerates. It typically ranges from 15 to 40 meters in thickness.
Relationships and Distribution
Lower contact
Rests conformably, though often with a sharply defined and highly erosive channel-scoured base, upon the thick coal seams and carbonaceous mudstones of the Black Shale and Coal Gr (also known as the Wankie Coal Fm).
Upper contact
Conformably and transitionally overlain by the dark, quiet-water carbonaceous shales of the Lower Madumabisa Mudstones Fm.
Regional extent
Widespread across the Mid-Zambezi Basin in Zimbabwe and southern Zambia. Middle Ecca Gr equivalent. It broadly correlates with the Vryheid Fm in the Main Karoo Basin of South Africa and the Kweneng Fm in Botswana.
GeoJSON
Fossils
Age
Depositional setting
High-energy continental braided river and fluvio-deltaic environments.
Additional Information