The Teekloof Formation is a geological formation that forms part of the

Beaufort Group The Beaufort Group is the third of the main subdivisions of the Karoo Supergroup in South Africa. It is composed of a lower Adelaide Subgroup and an upper Tarkastad Subgroup. It follows conformably after the Ecca Group and unconformably underlie ...

, one of the five geological groups that comprises the

Karoo Supergroup The Karoo Supergroup is the most widespread stratigraphic unit in Africa south of the Kalahari Desert. The supergroup consists of a sequence of units, mostly of nonmarine origin, deposited between the Late Carboniferous and Early Jurassic, a perio ...

in South Africa. The Teekloof Formation is the uppermost formation of Adelaide Subgroup deposits West of 24ºE and contains Middle to Late Permian-aged ( Guadalupian to Lopingian) deposits and four biozones ('' Pristerognathus'', ''

Tropidostoma ''Tropidostoma'' is a medium-sized herbivorous oudenodontid dicynodont therapsid that lived during the Late Permian (Lopingian) period in South Africa. The first ''Tropidostoma'' fossil was described by Harry Govier Seeley in 1889. Later two sub ...

'', '' Cistecephalus'', and ''

Daptocephalus ''Daptocephalus'' is an extinct genus of non- mammalian synapsid anomodont dicynodont, it which was found in Late Permian strata, in a biozone known precisely for the presence of fossils of this dicynodont, the ''Daptocephalus'' Zone, in the Ka ...

'' assemblage zones) of the Beaufort Group. It overlies the

Abrahamskraal Formation The Abrahamskraal Formation is a geological formation and is found in numerous localities in the Northern Cape, Western Cape, and the Eastern Cape of South Africa. It is the lowermost formation of the Adelaide Subgroup of the Beaufort Group, a ma ...

(the western correlate of the

Middleton Formation The Middleton Formation is a geological formation that extends through the Northern Cape, Western Cape, and Eastern Cape provinces of South Africa. It overlies the lower Abrahamskraal Formation, and is the eastern correlate, East of 24ºE, of th ...

). The Teekloof Formation does not underlie other units other than the younger Karoo

dolerites Diabase (), also called dolerite () or microgabbro, is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. Diabase dikes and sills are typically shallow intrusive bodies and often exhibit fine-grained ...

and sills that relate to the emplacement of the Early Jurassic Drakensberg Group to the east. Outcrops and exposures of the Teekloof Formation range from

Sutherland Sutherland ( gd, Cataibh) is a historic county, registration county and lieutenancy area in the Highlands of Scotland. Its county town is Dornoch. Sutherland borders Caithness and Moray Firth to the east, Ross-shire and Cromartyshire (later ...

through the mountain escarpments between Fraserburg and Beaufort West. The northernmost localities of the Teekloof Formation are found by Loxton, Victoria West and Richmond.

Geology

The Teekloof Formation overlies the

and is not capped by any other preserved sedimentation. Only East of 24ºE does the preservation of

rocks continue. There is no rock preservation in the western-southwestern portions of the

Karoo Basin The Karoo Supergroup is the most widespread stratigraphy, stratigraphic unit in Africa south of the Kalahari Desert. The group (stratigraphy), supergroup consists of a sequence of units, mostly of nonmarine origin, deposited between the Pennsylvan ...

. It is unclear whether rock preservation there ceased in the Late Permian due to localized basinal tectonics, or if that rock material was preserved but later weathered away. The Teekloof Formation has five subdivisions or members which are listed below (from oldest to youngest): * Poortjie Member - Correlates with the ''Pristerognathus'' Assemblage Zone * Hoedemaker Member - Correlates with the ''Tropidostoma'' Assemblage Zone * Oukloof Member - Correlates with the ''Cistecephalus'' Assemblage Zone * Steenkampsvlakte Member - Correlates with the ''Daptocephalus'' Assemblage Zone * Javanerskop Member - Correlates with the ''Daptocephalus'' Assemblage Zone

Lithologies

The sedimentary rocks of this

formation Formation may refer to: Linguistics * Back-formation, the process of creating a new lexeme by removing or affixes * Word formation, the creation of a new word by adding affixes Mathematics and science * Cave formation or speleothem, a secondar ...

are predominantly reddish or minor green

mudstone Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Mudstone is distinguished from '' shale'' by its lack of fissility (parallel layering).Blatt, H., and R.J. Tracy, 1996, ''Petrology. ...

s that are either structureless, horizontally laminated, or medium to thickly bedded.

Pedogenic Soil formation, also known as pedogenesis, is the process of soil genesis as regulated by the effects of place, environment, and history. Biogeochemical processes act to both create and destroy order (anisotropy) within soils. These alterations l ...

and diagenetic carbonate

nodules Nodule may refer to: *Nodule (geology), a small rock or mineral cluster *Manganese nodule, a metallic concretion found on the seafloor *Nodule (medicine), a small aggregation of cells *Root nodule Root nodules are found on the roots of plants, p ...

and also fossil gypsum rosettes occur in the

deposits. Interbedded with the

deposits are minor channel sandstones ranging from pale olive to greenish-grey in colour. The sandstones are fine to medium grained and preserve fining-upward sequences (e.g. from bottom to top: Massive, horizontally laminated, trough cross-bedded, and ripple cross-laminated sedimentary structures). In the uppermost sections of the Teekloof Formation, the Javanerskop Member contains ribbon-shaped, single storied sandstones. These sandstones in the uppermost sections contain numerous erosional surfaces lined with

siltstone Siltstone, also known as aleurolite, is a clastic sedimentary rock that is composed mostly of silt. It is a form of mudrock with a low clay mineral content, which can be distinguished from shale by its lack of fissility.Blatt ''et al.'' 1980, p ...

pellet conglomerates. Geologists consider the Teekloof Formation depositional environment to have been a floodplain

facies In geology, a facies ( , ; same pronunciation and spelling in the plural) is a body of rock with specified characteristics, which can be any observable attribute of rocks (such as their overall appearance, composition, or condition of formatio ...

association that underwent seasonal arid conditions and playa lake formation as indicated by the presence of fossil gypsum rosettes and carbonate

. The sandstone occurrences preserve evidence of deposition on point bars in a meandering river system. Seasonal waning flood level events are indicated by the fining upward sequences.

Paleontology

The Teekloof Formation is rich in fossil material and is particularly renowned for its diverse therapsid fossil fauna. Plant and invertebrate trace fossils are also found as are some preserved vertebrate fossil trackways. Well-known trackways of the

pareiasaur Pareiasaurs (meaning "cheek lizards") are an extinct clade of large, herbivorous parareptiles. Members of the group were armoured with scutes which covered large areas of the body. They first appeared in southern Pangea during the Middle Permian, ...

Bradysaurus ''Bradysaurus'' was a large, early and common pareiasaur, the fossils of which are known from the ''Tapinocephalus'' Assemblage Zone (Capitanian age) of the South African Karoo. Along with the similarly large dinocephalia, the bradysaurs cons ...

'', and therapsids '' Diictodon'' and ''

Tapinocaninus ''Tapinocaninus'' is an extinct genus of therapsids in the family Tapinocephalidae, of which it is the most basal member. Only one species is known, ''Tapinocaninus pamelae'' (meaning "Pam's humble canine"). Fossils have been found dating from t ...

'' have been found by the town Fraserburg.

References

{{Geology of South Africa, formations Geologic formations of South Africa Permian System of Africa Permian South Africa Mudstone formations Siltstone formations Sandstone formations Fluvial deposits Evaporite deposits Permian southern paleotemperate deposits Beaufort Group Fossiliferous stratigraphic units of Africa Paleontology in South Africa Formations Formations Formations