Clarens Formation

Clarens Formation
Clarens Formation
Ma PreꞒ Ꞓ O S D C P T J K Pg N
	Clarens, Free State
	Clarens Formation (South Africa)

The Clarens Formation is a

Karoo Basin.^[1]

Geology

The Clarens Formation is composed nearly entirely of fine to medium-grained, thickly-bedded sandstones that range from pale orange or pinkish to cream in color. It is characterized by its remarkable gross lithological uniformity and that its deposits mainly outcrop as high cliffs. These Clarens Formation cliffs frequently contain shallow caves and overhangs at the contact of the underlying Upper Elliot Formation (UEF) due to processes of erosion. This particular feature of the Clarens Formation lead to the initial naming of these rocks the “Cave Sandstone” in older literature.^[2]^[3] It is thought that the geographical range of the Clarens Formation was much greater millions of years ago, covering most of southern Africa in a vast sand dune environment which stretched out from the main Karoo Basin westwards into Namibia and into Zimbabwe in the northeast.^[4]^[5]^[6]^[7]

There has been very little recent research undertaken on Clarens Formation,

arid climate where dune fields were abundant.^[9]^[10]^[11] The Clarens Formation deposits have been categorized into three notable sedimentary facies

. These are laid out below:

Basal Zone 1: This
lenticular sandstones that contain various ripple structures, calcareous concretions and clay-pellet conglomerates. These have been interpreted as loess deposits. Various trace fossils are found in the mudstone
layers of the Basal Zone 1.

Middle Zone 2: The middle section of the Clarens Formation exhibit either massive or large-scale planar or cross trough bedding structures, and in some instances minor herringbone cross bedding. The sandstones are well sorted and the grain size is coarser than that found in the lower deposits. The sandstones from this facies and up are composed either of quartz arenites or greywackes. Scour and fill structures, and scour marks are also commonly observed in the upper sandstone deposits. These sedimentary facies have been interpreted as preserved sheet flood and ephemeral stream deposits, as well as playa lakes that were formed in a proper desert environment.
Upper Zone 3: In the upper sections of the Clarens Formation,
sphene, and hornblende. Thin, lenticular sandstones also reappear in the uppermost Clarens Formation, as do ripple marks and clay-pellet conglomerates, which reveals that the environment where these sedimentary rocks were formed was similar or the same as that of Basal Zone 1. Minor basalts begin to appear in the uppermost sections of the Clarens Formation which are interpreted as the commencement of the magmatic activity associated with the Drakensberg Group. The appearance of the basalts signals the termination of the sedimentation of the Karoo Basin. Extremely rare occurrences of shallow water structures have been found in the basaltic deposits.^[12]

Palaeontology

Paleontological finds of the Clarens Formation are less common than the underlying Upper

trackways of both large and small theropods, and also of small ornithischian dinosaurs. Petrified wood fragments, rhizoliths, coprolites, and planolites burrows have also been found.^[17]^[18]^[19]^[20]

Correlation

The Clarens Formation corresponds with numerous localities in Sub-Saharan Africa. It is currently considered to correlate in age with the Forest Sandstone of Zimbabwe, the Bodibeng Sandstone in the Tuli Basin of Botswana,^[21] and the Etjo Sandstone of Namibia. In South Africa, equivalent sedimentary facies to the Clarens Formation are present in the Lebombo Belt, north of Eswatini.

References

^ Broom, R. 1948. A contribution to our knowledge of the vertebrates of the Karroo Beds of South Africa. Transactions of the Royal Society of Edinburgh, 61, 577–629.
^ Beukes, N.J., 1970. Stratigraphy and sedimentology of the Cave Sandstone stage, Karoo System. In: S.H. Haughton (Editor), Proceedings and papers of the 2nd Gondwana symposium. Council for Scientific and Industrial Research, Pretoria, 321-341.
ISSN 1012-0750
.

ISSN 0078-8554
.

ISSN 1012-0750
.

^ Meiklejohn, K.I., 1997. The role of moisture in the weathering of the Clarens Formation of the KwaZulu-Natal Drakensberg: implications for the preservation of indigenous rock art. South African Geographical Journal, 79, pp.199-206.

S2CID 56420970
.

hdl:11660/7671

^ Eriksson, P.G., 1981. A palaeoenvironmental analysis of the Clarens Formationin the Natal Drakensberg. Transactions of the Geological Society of SouthAfrica, 84, 7-17.

^ Eriksson, P.G., 1986. Aeolian dune and alluvial fan deposits in the Clarens Formation of the Natal Drakensberg. Transactions of the Geological Societyof South Africa, 89, 389-393.

ISSN 1996-8590
.

ISSN 0899-5362.{{cite journal}}: CS1 maint: multiple names: authors list (link
)

^ Bordy, E.M., Bumby, A.J., Catuneanu, O. and Eriksson, P.G., 2004. Advanced early Jurassic termite (Insecta: Isoptera) nests: evidence from the Clarens Formation in the Tuli Basin, southern Africa. Palaios, 19(1), pp.68-78.

ISSN 0078-8554
.

ISSN 0567-7920.{{cite journal}}: CS1 maint: multiple names: authors list (link
)

^ Sues, H.D., Reisz, R.R., Hinic, S. and Raath, M.A., 2004. On the skull of Massospondylus carinatus Owen, 1854 (Dinosauria: Sauropodomorpha) from the Elliot and Clarens formations (Lower Jurassic) of South Africa. Annals of Carnegie Museum, 73(4), pp.239-257.

^ Kitching, J.W., 1979. Preliminary report on a clutch of six dinosaurian eggs from the Upper Triassic Elliot Formation, Northern Orange Free State.

ISSN 0037-9409
.

ISSN 1996-7489
.

S2CID 37548361
.

ISSN 1464-343X.{{cite journal}}: CS1 maint: multiple names: authors list (link
)

Retrieved from "https://en.wikipedia.org/w/index.php?title=Clarens_Formation&oldid=1215583081"

[1] Broom, R. 1948. A contribution to our knowledge of the vertebrates of the Karroo Beds of South Africa. Transactions of the Royal Society of Edinburgh, 61, 577–629.

[2] Beukes, N.J., 1970. Stratigraphy and sedimentology of the Cave Sandstone stage, Karoo System. In: S.H. Haughton (Editor), Proceedings and papers of the 2nd Gondwana symposium. Council for Scientific and Industrial Research, Pretoria, 321-341.

[3] ISSN 1012-0750
.

[4] ISSN 0078-8554
.

[5] ISSN 1012-0750
.

[6] Meiklejohn, K.I., 1997. The role of moisture in the weathering of the Clarens Formation of the KwaZulu-Natal Drakensberg: implications for the preservation of indigenous rock art. South African Geographical Journal, 79, pp.199-206.

[7] S2CID 56420970
.

[8] hdl:11660/7671

[9] Eriksson, P.G., 1981. A palaeoenvironmental analysis of the Clarens Formationin the Natal Drakensberg. Transactions of the Geological Society of SouthAfrica, 84, 7-17.

[10] Eriksson, P.G., 1986. Aeolian dune and alluvial fan deposits in the Clarens Formation of the Natal Drakensberg. Transactions of the Geological Societyof South Africa, 89, 389-393.

[11] ISSN 1996-8590
.

[12] ISSN 0899-5362.{{cite journal}}: CS1 maint: multiple names: authors list (link
)

[13] Bordy, E.M., Bumby, A.J., Catuneanu, O. and Eriksson, P.G., 2004. Advanced early Jurassic termite (Insecta: Isoptera) nests: evidence from the Clarens Formation in the Tuli Basin, southern Africa. Palaios, 19(1), pp.68-78.

[14] ISSN 0078-8554
.

[15] ISSN 0567-7920.{{cite journal}}: CS1 maint: multiple names: authors list (link
)

[16] Sues, H.D., Reisz, R.R., Hinic, S. and Raath, M.A., 2004. On the skull of Massospondylus carinatus Owen, 1854 (Dinosauria: Sauropodomorpha) from the Elliot and Clarens formations (Lower Jurassic) of South Africa. Annals of Carnegie Museum, 73(4), pp.239-257.

[17] Kitching, J.W., 1979. Preliminary report on a clutch of six dinosaurian eggs from the Upper Triassic Elliot Formation, Northern Orange Free State.

[18] ISSN 0037-9409
.

[19] ISSN 1996-7489
.

[20] S2CID 37548361
.

[21] ISSN 1464-343X.{{cite journal}}: CS1 maint: multiple names: authors list (link
)

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[9]

[10]

[11]

[12]

[17]

[18]

[19]

[20]

[21]

Geology

Palaeontology

Correlation

See also

References