The Teekloof Formation is a

geological formation A geological formation, or simply formation, is a body of rock having a consistent set of physical characteristics (lithology) that distinguishes it from adjacent bodies of rock, and which occupies a particular position in the layers of rock expo ...

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 under ...

, 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 per ...

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

. The Teekloof Formation is the uppermost formation of Adelaide Subgroup deposits West of 24ºE and contains Middle to Late

Permian The Permian ( ) is a geologic period and System (stratigraphy), stratigraphic system which spans 47 million years, from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.902 Mya. It is the s ...

-aged (

Guadalupian The Guadalupian is the second and middle Series (stratigraphy), series/Epoch (geology), epoch of the Permian. The Guadalupian was preceded by the Cisuralian and followed by the Lopingian. It is named after the Guadalupe Mountains of New Mexico an ...

Lopingian The Lopingian is the uppermost series/last epoch of the Permian. It is the last epoch of the Paleozoic. The Lopingian was preceded by the Guadalupian and followed by the Early Triassic. The Lopingian is often synonymous with the informal te ...

) deposits and four

biozone In biostratigraphy, biostratigraphic units or biozones are intervals of geological strata that are defined on the basis of their characteristic fossil taxon, taxa, as opposed to a Lithostratigraphy, lithostratigraphic unit which is defined by the ...

s (''

Pristerognathus ''Pristerognathus'' is an extinct genus of therocephalian, known from the late Middle Permian (Capitanian) of South Africa. It lends its name to the now defunct Pristerognathus Assemblage Zone of the Beaufort Group of South African geological s ...

'', ''

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 su ...

'', '' Cistecephalus'', and '' Daptocephalus'' assemblage zones) of the Beaufort Group. It overlies the Abrahamskraal Formation (the western correlate of the Middleton Formation). The Teekloof Formation does not underlie other units other than the younger Karoo dolerites and sills that relate to the emplacement of the Early

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...

Drakensberg Group to the east.

Outcrop An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth and other terrestrial planets. Features Outcrops do not cover the majority of the Earth's land surface because in most p ...

s and exposures of the Teekloof Formation range from

Sutherland Sutherland () is a Counties of Scotland, historic county, registration county and lieutenancy areas of Scotland, lieutenancy area in the Scottish Highlands, Highlands of Scotland. The name dates from the Scandinavian Scotland, Viking era when t ...

through the mountain escarpments between

Fraserburg Fraserburg is a town in the Karoo region of South Africa's Northern Cape province. It is located in the Karoo Hoogland Local Municipality. The town has some of the coldest winters in South Africa. The nearest towns are Williston, Northern Cape, W ...

and

Beaufort West Beaufort West (Afrikaans: ''Beaufort-Wes''; Xhosa: ''eBhobhofolo'') is a town in the Western Cape province in South Africa. It is the largest town in the arid Great Karoo region, and is known as the "Capital of the Karoo". It forms part of the ...

. The northernmost localities of the Teekloof Formation are found by Loxton, Victoria West and Richmond.

Geology

The Teekloof Formation overlies the Abrahamskraal Formation 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 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 per ...

. It is unclear whether rock preservation there ceased in the Late

due to localized basinal

tectonics Tectonics ( via Latin ) are the processes that result in the structure and properties of the Earth's crust and its evolution through time. The field of ''planetary tectonics'' extends the concept to other planets and moons. These processes ...

, 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 rock Sedimentary rocks are types of rock (geology), rock formed by the cementation (geology), cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or de ...

s of this formation 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.Blatt, H., and R.J. Tracy, 1996, ''Petrology.'' New York, New York, ...

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

carbonate A carbonate is a salt of carbonic acid, (), characterized by the presence of the carbonate ion, a polyatomic ion with the formula . The word "carbonate" may also refer to a carbonate ester, an organic compound containing the carbonate group ...

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 A deposit account is a bank account maintained by a financial institution in which a customer can deposit and withdraw money. Deposit accounts can be savings accounts, current accounts or any of several other types of accounts explained below. ...

. Interbedded with the

deposits are minor channel

sandstone Sandstone is a Clastic rock#Sedimentary clastic rocks, clastic sedimentary rock composed mainly of grain size, sand-sized (0.0625 to 2 mm) silicate mineral, silicate grains, Cementation (geology), cemented together by another mineral. Sand ...

s ranging from pale olive to greenish-grey in colour. The

s are fine to medium grained and preserve fining-upward sequences (e.g. from bottom to top: Massive, horizontally laminated, trough

cross-bedded In geology, cross-bedding, also known as cross-stratification, is layering within a stratum and at an angle to the main bedding plane. The sedimentary structures which result are roughly horizontal units composed of inclined layers. The original ...

, and ripple cross-laminated

sedimentary structures Sedimentary structures include all kinds of features in sediments and sedimentary rocks, formed at the time of deposition. Sediments and sedimentary rocks are characterized by bedding, which occurs when layers of sediment, with different parti ...

). In the uppermost sections of the Teekloof Formation, the Javanerskop Member contains ribbon-shaped, single storied

s. 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. Although its permeabil ...

pellet conglomerates.

Geologist A geologist is a scientist who studies the structure, composition, and History of Earth, history of Earth. Geologists incorporate techniques from physics, chemistry, biology, mathematics, and geography to perform research in the Field research, ...

s consider the Teekloof Formation depositional environment to have been a

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river. Floodplains stretch from the banks of a river channel to the base of the enclosing valley, and experience flooding during periods of high Discharge (hydrolog ...

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

association that underwent seasonal

arid Aridity is the condition of geographical regions which make up approximately 43% of total global available land area, characterized by low annual precipitation, increased temperatures, and limited water availability.Perez-Aguilar, L. Y., Plata ...

conditions and

playa lake A dry lake bed, also known as a playa (), is a basin or Depression (geology), depression that formerly contained a standing surface water body, which disappears when evaporation processes exceed recharge. If the floor of a dry lake is covered b ...

formation as indicated by the presence of fossil gypsum rosettes and

. The

occurrences preserve evidence of deposition on

point bar A point bar is a depositional feature made of alluvium that accumulates on the inside bend of streams and rivers below the slip-off slope. Point bars are found in abundance in mature or meandering streams. They are crescent-shaped and located on ...

s in a

meander A meander is one of a series of regular sinuous curves in the Channel (geography), channel of a river or other watercourse. It is produced as a watercourse erosion, erodes the sediments of an outer, concave bank (cut bank, cut bank or river cl ...

ing river system. Seasonal waning flood level events are indicated by the fining upward sequences.

Paleontology

The Teekloof Formation is rich in

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...

material and is particularly renowned for its diverse therapsid

fauna Fauna (: faunae or faunas) is all of the animal life present in a particular region or time. The corresponding terms for plants and fungi are ''flora'' and '' funga'', respectively. Flora, fauna, funga and other forms of life are collectively ...

. Plant and

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

trace fossil A trace fossil, also called an ichnofossil (; ), is a fossil record of biological activity by lifeforms, but not the preserved remains of the organism itself. Trace fossils contrast with body fossils, which are the fossilized remains of part ...

s are also found as are some preserved

vertebrate Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...

fossil trackway A fossil track or ichnite ( Greek "''ιχνιον''" (''ichnion'') – a track, trace or footstep) is a fossilized footprint. This is a type of trace fossil. A fossil trackway is a sequence of fossil tracks left by a single organism. Over the ye ...

s. 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 osteoderms which covered large areas of the body. They first appeared in southern Pangea during the Middle Per ...

Bradysaurus ''Bradysaurus'' is a genus of large, primitive and widespread pareiasaur. They possessed a covering of armoured scutes, likely serving as defense against their main predators, the gorgonopsians. Fossils of ''Bradysaurus'' are known from the ''T ...

'', and therapsids ''

Diictodon ''Diictodon'' (meaning "two weasel teeth") is an extinct genus of pylaecephalid dicynodont that lived during the Late Permian period, approximately 255 million years ago. Fossils have been found in the ''Cistecephalus'' Assemblage Zone of the M ...

'' and ''

Tapinocaninus ''Tapinocaninus'' (Greek for "humble"- tapino, and "canine"- caninus) 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 "Pamela's ...

'' have been found by the town

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