Tshidzi Formation

Tshidzi Fm

Period:

Carboniferous, Permian

Age Interval:

Late Carboniferous-Early Permian (Moscovian-Sakmarian)

Province:
SouthAfrica-Namibia-Botswana

Type Locality and Naming

Soutpansberg, Tshipise, Pafuri, Tuli, and Springbok Flats Basins (Limpopo, North West, and Gauteng provinces, South Africa). Named after the Tshidzi River (or Tshidzi area) in the Limpopo Province of northern South Africa. It was formally established as a distinct lithostratigraphic unit by G. Brandl in 1981 to classify the basal, glaciogenic deposits of the Karoo Supergroup resting in the isolated northern rift basins.

Synonym:

Lithology and Thickness

A relatively thin, patchy, and highly erratic glaciogenic succession. It typically ranges from just a few meters up to 20 meters in thickness, though it can occasionally reach up to 100 meters where it fills deep, scoured paleovalleys in the basement rock. It consists predominantly of massive, poorly sorted, polymictic diamictite (tillite) composed of angular to sub-rounded clasts of older basement rocks (like Soutpansberg quartzite or Limpopo Belt gneiss) supported in a dark, sandy to argillaceous (muddy) matrix. It frequently contains minor, discontinuous lenses of glaciofluvial sandstone and conglomerate.

Lithology Pattern:

Glacial till

Relationships and Distribution

Lower contact

Rests with a profound regional unconformity directly upon the deeply scoured, irregular paleotopography of the ancient Precambrian basement (which includes the Soutpansberg Group, Limpopo Mobile Belt, or the Bushveld Igneous Complex depending on the specific basin).

Upper contact

Conformably (and often rapidly) overlain by the coal-bearing clastics of the Madzaringwe Fm (in the northern basins) or the Hammanskraal Fm (in the Springbok Flats Basin).

Regional extent

Present at the base of the sequence in the fault-bounded, east-west trending Karoo remnant basins of northern South Africa (Soutpansberg, Tshipise, Pafuri, and Tuli) as well as the Springbok Flats Basin further south. Dwyka Gr equivalent in the northern basins and Springbok Flats Basin. It is the direct regional chronostratigraphic equivalent of the Dwyka Gr in the Main Karoo Basin and the Waterkloof Fm in the Ellisras Basin.

GeoJSON

null

Fossils

Age

Late Carboniferous-Early Permian (Moscovian-Sakmarian)

Age Span:

Beginning stage:

Moscovian

Fraction up in beginning stage:

0.5

Beginning date (Ma):

311.09

Ending stage:

Sakmarian

Fraction up in the ending stage:

0.5

Ending date (Ma):

292.02

Depositional setting

Depositional pattern:

Additional Information

Compiler:

From the O. Catuneanu et al. / Journal of African Earth Sciences 43 (2005) 211–253; Brandl, G. (1981): The geology of the Messina area. Explanation of Sheet 2230, Geological Survey of South Africa; Johnson, M.R., et al. (2006): Sedimentary rocks of the Karoo Supergroup. In: The Geology of South Africa.