Research Letters

Waterford Formation in the south-eastern Karoo: Implications for basin development

Bruce S. Rubidge, P. John Hancox, Richard Mason
South African Journal of Science | Vol 108, No 3/4 | a829 | DOI: | © 2012 Bruce S. Rubidge, P. John Hancox, Richard Mason | This work is licensed under CC Attribution 4.0
Submitted: 11 July 2011 | Published: 07 March 2012

About the author(s)

Bruce S. Rubidge, University of the Witwatersrand, South Africa
P. John Hancox, University of the Witwatersrand, South Africa
Richard Mason, University of the Witwatersrand, South Africa


Extensive research on the rocks of the Karoo Supergroup has shown that this sequence, which contains an unsurpassed record of Permian–Jurassic tetrapods, records a largely unbroken stratigraphic succession from 300 Ma to 180 Ma. This Gondwanan succession was deposited in a changing environmental setting reflecting glacial marine through deltaic to fluvial and aeolian desert conditions. The contact between the Ecca and Beaufort Groups (at the top of the Waterford Formation of the Ecca Group) in the southern and western Karoo represents a change in depositional environment from a subaqueous to a subaerial delta plain. By contrast, the Waterford Formation has not yet been recognised in the south-eastern Karoo Basin, which might imply that a major unconformity is present between the Fort Brown Formation of the Ecca Group, deposited in a prodelta environment, and the overlying fluvially deposited Koonap Formation of the Beaufort Group. From careful documentation of lithofacies and sedimentological data, it can be demonstrated that the Waterford Formation is indeed present in the south-eastern part of the basin and that no major unconformity is present – a fact that has implications for the mapping of Karoo rocks in the Eastern Cape Province of South Africa, for understanding the depositional environment of ’reptilian‘ fossils from the lowermost Beaufort in this part of the Karoo basin, and for basin development models.


Karoo Supergroup; Beaufort; Ecca; stratigraphy; deposits


Total abstract views: 1483
Total article views: 2452


Johnson MR. Sandstone petrography, provenance and plate tectonic setting in Gondwana context of the southeastern Cape-Karoo Basin. S Afr J Geol. 1991;94:137–154.

Catuneanu O, Hancox PJ, Rubidge BS. Reciprocal flexural behaviour and contrasting stratigraphies: A new basin development model for the Karoo retroarc foreland system, South Africa. Basin Res. 1998;10:417–439.

Rubidge BS. Re-uniting lost continents – Fossil reptiles from the ancient Karoo and their wanderlust. S Afr J Geol. 2005;108:135–172.

Tankard A, Welsink H, Aukes P, Newton R, Stettler E. Tectonic evolution of the Cape and Karoo basins of South Africa. Mar Petrol Geol. 2009;26:1379–1412. marpetgeo.2009.01.022

Visser JNJ. Changes in the sediment transport direction in the Cape-Karoo Basin (Silurian-Triassic) in South Africa. S Afr J Sci. 1979;75:72–75.

Hancox PJ. A stratigraphic, sedimentological and palaeoenvironmental synthesis of the Beaufort-Molteno contact in the Karoo Basin. PhD thesis, Johannesburg, University of the Witwatersrand, 1998.

Visser JNJ. A review of the Stormberg Group and Drakensberg volcanics in southern Africa. Palaeont Afr. 1984;25:5–27.

Rubidge BS. South Africa’s oldest land living reptiles from the Ecca-Beaufort transition in the southern Karoo. S Afr J Sci. 1987;83:165–166.

Rubidge BS, Hancox PJ, Catuneanu O. Sequence analysis of the Ecca-Beaufort contact in the southern Karoo of South Africa. S Afr J Geol. 2000;103:81–96.

Smith AM, Zawada PK. The Ecca-Beaufort transition zone near Philipstown, Cape Province: A marine shelf sequence. S Afr J Geol. 1988;91:75–82.

Visser JNJ, Loock JC. The nature of the Ecca-Beaufort transition in the western and central Orange Free State. Trans Geol Soc S Afr. 1974;81:185–191.

Zawada PK, Cadle AB. Position of the Ecca-Beaufort contact in the southwestern Orange Free State: An evaluation of four possible alternatives. S Afr J Geol. 1987;91:49–56.

Welman J, Loock JC, Rubidge BS. New evidence for diachroneity of the Ecca-Beaufort contact (Karoo Supergroup, South Africa). S Afr J Sci. 2001;97:320–322.

Wickens HdV. Basin floor fan building turbidites of the southwestern Karoo Basin, Permian Ecca Group, South Africa. PhD thesis, Port Elizabeth, University of Port Elizabeth, 1994.

Johnson MR, Le Roux FG. The geology of the Grahamstown area. Council for Geosciences. The Geological Survey of South Africa explanation sheet. 1994;3326:1–41.

Johnson MR. Stratigraphy and sedimentology of the Cape and Karoo sequences in the Eastern Cape Province. PhD thesis, Grahamstown, Rhodes University, 1976.

Kingsley CS. Stratigraphy and sedimentology of the Ecca Group in the Eastern Cape province, South Africa. PhD thesis, Port Elizabeth, University of Port Elizabeth, 1977.

Catuneanu O, Bowker B. Sequence stratigraphy of the Koonap and Middleton fluvial formations in the Karoo foredeep South Africa. J Afr Earth Sci. 2001;33:579–595.

Kingsley CS. Depositional framework as basis for defining the Ecca-Beaufort transition in the Karoo Basin [Abstract]. Proceedings of the Symposium on Stratigraphic Problems relating to the Beaufort–Ecca Contact; 1987 Apr 15–16; Pretoria, South Africa. Pretoria: Geological Survey of South Africa, 1987; p. 3–4.

Cole DI. Proposed stratigraphic revision of the Adelaide Subgroup in the southern part of the main Karoo Basin, South Africa. Report No. 2006-0292:11p. Pretoria: Council for Geoscience; 2006.

Ridente D, Trincardi F. Pleistocene ‘muddy’ forced-regression deposits on the Adriatic shelf: A comparison with prodelta deposits of the late Holocene highstand mud wedge. Mar Geol. 2005;222:213–233.

Selley RC. Applied sedimentology. London: Academic Press; 2000.

Boggs S. Principles of sedimentology and stratigraphy. 2nd ed. New Jersey: Prentice-Hall; 1995.

Reineck HE, Singh IB. Depositional sedimentary environments. Berlin: Springer; 1975.

Rubidge BS. A palaeontological and palaeoenvironmental synthesis of the Permian Ecca-Beaufort in the southern Karoo between Prince Albert and Rietbron, Cape Province, South Africa. PhD thesis, Port Elizabeth, University of Port Elizabeth, 1988.

Stauffer PH. Grain-flow deposits and their implications: Santa Yves Mountains, California. J Sedim Petrol. 1967;37:487–508.

Tankard AJ. On the depositional response to thusting and lithospheric flexure: Examples from the Appalachian and Rocky Mountain basins. In: Allen PA, Homewood P, editors. Foreland basins. Oxford: Blackwell, 2009; p. 367–392.

Massari F, Grandesso P, Stefani C, Jobstraibizer PG. A small polyhistory foreland basin evolving in a context of oblique convergence: The Venetian Basin (Chattian to Recent, Southern Alps, Italy). In: Allen PA, Homewood P, editors. Foreland basins. Oxford: Blackwell Scientific, 2009; p. 141–168.

Mills PC. Genesis and diagnostic value of soft-sediment deformation structures – A review. Sed Geol. 1983;35:83–104.

Miall AD. The geology of fluvial deposits: Sedimentary facies, basin analysis and petroleum geology. Berlin: Springer-Verlag; 1996.

Miall AD. The geology of stratigraphic sequences. Berlin: Springer-Verlag; 1997.

Reader Comments

Before posting a comment, read our privacy policy.

Post a comment (login required)


Crossref Citations

1. A brief lithostratigraphic review of the Abrahamskraal and Koonap formations of the Beaufort Group, South Africa: Towards a basin-wide stratigraphic scheme for the Middle Permian Karoo
Michael Oliver Day, Bruce Sidney Rubidge
Journal of African Earth Sciences  vol: 100  first page: 227  year: 2014  
doi: 10.1016/j.jafrearsci.2014.07.001