Pietermaritzburg Formation

Pietermaritzburg Fm

Period:

Permian

Age Interval:

Early Permian (Asselian- Sakmarian)

Province:
SouthAfrica-Namibia-Botswana

Type Locality and Naming

Named after the city of Pietermaritzburg in the KwaZulu-Natal Province of South Africa, where it is typically developed and well-exposed. It was formally established to designate the basal argillaceous (muddy) unit of the Ecca Group in the eastern, central, and northeastern sectors of the Karoo Basin. Lower formation in Ecca Gr in Main Karoo Basin (Eastern/Northern Forebulge).

Synonym:

Lithology and Thickness

A thick, monotonous, and fine-grained basinal succession. It consists predominantly of dark grey to black, heavily bioturbated, highly carbonaceous and silty shales and mudstones.

Lithology Pattern:

Claystone

Relationships and Distribution

Lower contact

Conformably and transitionally overlies the massive glaciogenic diamictites of the Dwyka Gr.

Upper contact

Conformably and transitionally overlain by the sandy, coal-bearing fluvio-deltaic deposits of the Vryheid Fm.

Regional extent

Restricted to the eastern, central, and northeastern parts of the Main Karoo Basin. It outcrops prominently in KwaZulu-Natal and extends deep into the subsurface of the Mpumalanga and Free State provinces.

Lower Ecca Gr (historically). It is the direct regional chronostratigraphic equivalent of the Prince Albert Fm (and the lower Whitehill Fm) found in the southern and western parts of the Main Karoo Basin.

GeoJSON

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Fossils

Age

Early Permian (Asselian- Sakmarian)

Age Span:

Beginning stage:

Asselian

Fraction up in beginning stage:

0.1

Beginning date (Ma):

298.35

Ending stage:

Sakmarian

Fraction up in the ending stage:

1.0

Ending date (Ma):

290.51

Depositional setting

Deep-water marine to extensive inland sea environment (often referred to as the "Ecca Sea").

Depositional pattern:

Additional Information

Compiler:

From the O. Catuneanu et al. / Journal of African Earth Sciences 43 (2005) 211–253; Johnson, M.R., et al. (2006): Sedimentary rocks of the Karoo Supergroup. In: The Geology of South Africa; Tavener-Smith, R., et al. (1988): Sedimentary models for coal formation in the Vryheid Formation, northern Karoo Basin.