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Teekloof Formation
The Teekloof Formation is a geological formation that forms part of the Beaufort Group, one of the five geological groups that comprises the Karoo Supergroup 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'', ''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 Drakensberg Group to the east. Outcrops and exposures of the Teekloof Formation range from Sutherland through the mountain escarpments between Fraserburg and Beaufort West. The northernmost localities of the Teekloof Formation are found by Loxton, Victoria We ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 exposed in a geographical region (the stratigraphic column). It is the fundamental unit of lithostratigraphy, the study of strata or rock layers. A formation must be large enough that it can be mapped at the surface or traced in the subsurface. Formations are otherwise not defined by the thickness of their rock strata, which can vary widely. They are usually, but not universally, tabular in form. They may consist of a single lithology (rock type), or of alternating beds of two or more lithologies, or even a heterogeneous mixture of lithologies, so long as this distinguishes them from adjacent bodies of rock. The concept of a geologic formation goes back to the beginnings of modern scientific geology. The term was used by Abraham Gottlob Wer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biozone
In biostratigraphy, biostratigraphic units or biozones are intervals of geological strata that are defined on the basis of their characteristic fossil taxa, as opposed to a lithostratigraphic unit which is defined by the lithological properties of the surrounding rock. A biostratigraphic unit is defined by the zone fossils it contains. These may be a single taxon or combinations of taxa if the taxa are relatively abundant, or variations in features related to the distribution of fossils. The same strata may be zoned differently depending on the diagnostic criteria or fossil group chosen, so there may be several, sometimes overlapping, biostratigraphic units in the same interval. Like lithostratigraphic units, biozones must have a type section designated as a stratotype. These stratotypes are named according to the typical taxon (or taxa) that are found in that particular biozone. The boundary of two distinct biostratigraphic units is called a ''biohorizon''. Biozones can be furthe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loxton, Northern Cape
Loxton is a town in the Karoo region of South Africa's Northern Cape province. Within the Ubuntu Local Municipality of the Pixley ka Seme District Municipality It is in one of the major wool-producing and one of the largest garlic-producing areas in South Africa. With a population of 1,053 in 2011, the area is quiet and sparsely populated. Afrikaans is the most widely spoken language in the town. History Loxton was originally a farm called Phizantefontein, which was owned by A.E. Loxton, whom the town is named after. The farm was bought from him in 1899 by the Dutch Reformed Church for £7,500 so as to establish a parish for local farmers. The town is believed to have been named after A.E Loxton due to a £50 donation he made to fund the salary of the town's first Dutch Reformed Church minister. The town's first church building and schoolhouse was built in 1900. Tree-lined streets and flood irrigation channels that run alongside the town's main roads were completed in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beaufort West
Beaufort West (Afrikaans: ''Beaufort-Wes''; Xhosa: ''eBhofolo'') 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 Beaufort West Local Municipality, with 34,085 inhabitants in 2011. It is the centre of an agricultural district based mainly on sheep farming, and is a significant town and logistical support hub on the N1 national road. Next door to Beaufort West is the Karoo National Park. Important Permian era fossils have been found in the area to the west of the town. Initially found by David Baird, son of the local magistrate in 1827. The old Town Hall and the Dutch Reformed Church have been declared national monuments. History Beaufort West was the first town to be established in the central Karoo. The town was founded in 1818 and initially named ''Beaufort'' after Henry Somerset, 5th Duke of Beaufort, who was the father of Lord Charles Henry Somerset ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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, Sutherland, Loxton and Leeu-Gamka, all of which are more than 100 km distant. A particularly good example of a corbelled house can be found in the town, there are others in the district. The town is also well known for the large number of unique and well-preserved fossil finds that litter the surrounding area. History The earliest known inhabitants of the area were the San people and their artefacts and rock paintings can still be found in the area. The first Europeans to arrive in the region were Trekboers who arrived in 1759. The first settler to be recorded in these parts was Willem Steenkamp, after whom the Steenkampsberg is named. In 1851 Fraserburg was established on the farm Rietfontein and named after the Scottish immigrant Reverend Col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sutherland, Northern Cape
Sutherland is a town with about 2,841 inhabitants in the Northern Cape province of South Africa. It lies in the western Roggeveld Mountains in the Karoo. History Sutherland was founded in 1855 as a church and market town to serve the area's sheep farmers. By 1872 the town had a population of 138 registered citizens living in 19 houses. The large Dutch Reformed church in the centre of Sutherland was built in 1899. During the Anglo Boer War the church was used as a fort by garrisoned British soldiers. During the war a number of engagements between British and Boer forces occurred in the town. In one such engagement a force of 250 Boer commandos attacked the local British garrison for 10 hours. The ruins of a fort can be found on the outskirts of town on the hill called Rebelskop. This was named after this engagement. Economy Major economic activities include tourism and sheep farming. The area includes at least twelve registered B&B's, guest houses and guest farms. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Outcrop
An outcrop or rocky outcrop is a visible exposure of bedrock or ancient superficial deposits on the surface of the Earth. Features Outcrops do not cover the majority of the Earth's land surface because in most places the bedrock or superficial deposits are covered by soil and vegetation and cannot be seen or examined closely. However, in places where the overlying cover is removed through erosion or tectonic uplift, the rock may be exposed, or ''crop out''. Such exposure will happen most frequently in areas where erosion is rapid and exceeds the weathering rate such as on steep hillsides, mountain ridges and tops, river banks, and tectonically active areas. In Finland, glacial erosion during the last glacial maximum (ca. 11000 BC), followed by scouring by sea waves, followed by isostatic uplift has produced many smooth coastal and littoral outcrops. Bedrock and superficial deposits may also be exposed at the Earth's surface due to human excavations such as quarrying and build ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 Mya. The Jurassic constitutes the middle period of the Mesozoic, Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified. The start of the Jurassic was marked by the major Triassic–Jurassic extinction event, associated with the eruption of the Central Atlantic magmatic province, Central Atlantic Magmatic Province. The beginning of the Toarcian Stage started around 183 million years ago and is marked by an extinction event associated with widespread Anoxic event, oceanic anoxia, ocean acidification, and elevated temperatures likely caused by the eruption of the Karoo-Ferrar, Karoo-Ferrar large igneous provinces. The end of the Jurassic, however, has no clear boundary with the Cretaceous and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sill (geology)
In geology, a sill is a tabular sheet intrusion that has intruded between older layers of sedimentary rock, beds of volcanic lava or tuff, or along the direction of foliation in metamorphic rock. A ''sill'' is a ''concordant intrusive sheet'', meaning that a sill does not cut across preexisting rock beds. Stacking of sills builds a sill complex . and a large magma chamber at high magma flux. In contrast, a dike is a discordant intrusive sheet, which does cut across older rocks. Sills are fed by dikes, except in unusual locations where they form in nearly vertical beds attached directly to a magma source. The rocks must be brittle and fracture to create the planes along which the magma intrudes the parent rock bodies, whether this occurs along preexisting planes between sedimentary or volcanic beds or weakened planes related to foliation in metamorphic rock. These planes or weakened areas allow the intrusion of a thin sheet-like body of magma paralleling the existing bedding pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 to aphanitic chilled margins which may contain tachylite (dark mafic glass). ''Diabase'' is the preferred name in North America, while ''dolerite'' is the preferred name in the rest of the English-speaking world, where sometimes the name ''diabase'' refers to altered dolerites and basalts. Some geologists prefer to avoid confusion by using the name ''microgabbro''. The name ''diabase'' comes from the French ', and ultimately from the Greek - meaning "act of crossing over, transition". Petrography Diabase normally has a fine but visible texture of euhedral lath-shaped plagioclase crystals (62%) set in a finer matrix of clinopyroxene, typically augite (20–29%), with minor olivine (3% up to 12% in olivine diabase), magnetite (2%), and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 the Teekloof Formation. Outcrops and exposures of the Middleton Formation range from Graaff-Reinet in the Eastern Cape onwards. The Middleton Formation's type locality lies near the small hamlet, Middleton, approximately 25 km south of Cookhouse. Other exposures lie in hillsides along the Great Fish River in the Eastern Cape. The Middleton Formation forms part of the Adelaide Subgroup of the Beaufort Group, which itself forms part of the Karoo Supergroup. Geology The Middleton Formation is the eastern correlate of the Teekloof Formation. Both these formations overlie the Abrahamskraal Formation. The upper Middleton Formation correlates with eastern exposures of the uppermost ''Pristerognathus'' Assemblage Zone, and is late Middle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daptocephalus Assemblage Zone
The ''Daptocephalus'' Assemblage Zone is a tetrapod assemblage zone or biozone found in the Adelaide Subgroup of the Beaufort Group, a majorly fossiliferous and geologically important geological Group of the Karoo Supergroup in South Africa.Rubidge, B. S. (1995). Biostratigraphy of the Beaufort Group (Karoo Supergroup). ''Biostratigraphic series''. This biozone has outcrops located in the upper Teekloof Formation west of 24°E, the majority of the Balfour Formation east of 24°E, and the Normandien Formation in the north. It has numerous localities which are spread out from Colesberg in the Northern Cape, Graaff-Reniet to Mthatha in the Eastern Cape, and from Bloemfontein to Harrismith in the Free State. The ''Daptocephalus'' Assemblage Zone is one of eight biozones found in the Beaufort Group and is considered Late Permian (Lopingian) in age. Its contact with the overlying ''Lystrosaurus'' Assemblage Zone marks the Permian-Triassic boundary. Previously known as the ''Dicynodo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
