Middleton Fm
Type Locality and Naming
Main Karoo Basin, South Africa. Named after the town of Middleton in the Eastern Cape, South Africa. It forms the middle sequence of the Adelaide Subgroup south of the basin hinge line. Lowermost formation in Beaufort Gr
Synonym:
Lithology and Thickness
Characterized by a significant shift in terrestrial deposition. It consists of thick, upward-fining cycles of pale grey fine-grained sandstones and, most distinctively, red to purplish mudstones.
Relationships and Distribution
Lower contact
Conformably overlies the Koonap Fm.
Upper contact
Conformably overlain by the fluvial mudstones and sandstones of the Balfour Fm
Regional extent
Widespread across the southern portion of the Main Karoo Basin. Correlates broadly with the lower Teekloof Fm in the western Karoo Basin and the upper part of the Assise de transition in the Congo Basin.
GeoJSON
Fossils
Highly fossiliferous. It hosts three successive and famous tetrapod biostratigraphic zones: the Pristerognathus, Tropidostoma, and Cistecephalus Assemblage Zones, recording a diverse ecosystem of dicynodonts, gorgonopsians, and therocephalians.
Age
Depositional setting
A semi-arid, highly seasonal terrestrial environment dominated by meandering river channels and expansive, well-drained, oxidized floodplains.
Additional Information