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101-483: The Enon Formation was formed along the southern section of South Africa during the break up of Gondwana when there was widespread erosion of rocks comprising the Cape Fold Belt . It is considered to be Late Jurassic to Early Cretaceous in age although more thorough dating needs to be undertaken. It provides important geological data on the change in landscape during the break-up of Gondwana in relation to

202-618: A co-operative in the area. May 2007 the Swellendam VOR SWV 114.4 MHz was permanently withdrawn. Drostdy arms – In 1804, when the Cape Colony was ruled by the Batavian Republic , the government assigned armorial seals to each of the drostdyen, i.e. administrative districts. Swellendam was given the arms of its founder, Hendrik Swellengrebel , namely a golden shield displaying a blue fleur de lis with

303-642: A complex series of orogenic events assembled the eastern parts of Gondwana (eastern Africa, Arabian-Nubian Shield, Seychelles, Madagascar, India, Sri Lanka, East Antarctica, and Australia) c. 750 to 530 Ma . First, the Arabian-Nubian Shield collided with eastern Africa (in the Kenya-Tanzania region) in the East African Orogeny c. 750 to 620 Ma . Then Australia and East Antarctica were merged with

404-599: A continuous arc chain, the direction of subduction was different between the Australian-Tasmanian and New Zealand-Antarctica arc segments. Many terranes were accreted to Eurasia during Gondwana's existence, but the Cambrian or Precambrian origin of many of these terranes remains uncertain. For example, some Palaeozoic terranes and microcontinents that now make up Central Asia, often called the "Kazakh" and "Mongolian terranes", were progressively amalgamated into

505-486: A curved band surrounding the southern edge of the larger Kirkwood Formation. Near Heidelberg, the Enon is composed of greenish Bokkeveld shale clasts and vein quartz. Nearer Riversdale , Witteberg sandstone clasts are also present. At Herbertsdale, a large section is exposed, often interfingered with the neighbouring Kirkwood Formation. The southern portion of the Enon is composed mainly of angular Bokkeveld shale clasts in

606-746: A diversified assemblage of true insects. In Gondwana, in contrast, ice and, in Australia, volcanism decimated the Devonian flora to a low-diversity seed fern flora – the pteridophytes were increasingly replaced by the gymnosperms which were to dominate until the Mid-Cretaceous. Australia, however, was still located near the Equator during the Early Carboniferous, and during this period, temnospondyl and lepospondyl amphibians and

707-472: A few million years, reached its peak at c. 200 Ma , and coincided with the Triassic–Jurassic extinction event . The reformed Gondwanan continent was not precisely the same as that which had existed before Pangaea formed; for example, most of Florida and southern Georgia and Alabama is underlain by rocks that were originally part of Gondwana, but this region stayed attached to North America when

808-594: A gradual decline during the Triassic while ferns, though never dominant, managed to diversify. The brief period of icehouse conditions during the Triassic–Jurassic extinction event had a dramatic impact on dinosaurs but left plants largely unaffected. The Jurassic was mostly one of hot-house conditions and, while vertebrates managed to diversify in this environment, plants have left little evidence of such development, apart from Cheiroleidiacean conifers and Caytoniales and other groups of seed ferns. In terms of biomass,

909-518: A north-east motion about 90 million years ago. While subduction direction changed, it remained oblique (and not perpendicular) to the coast of South America, and the direction change affected several subduction zone -parallel faults including Atacama , Domeyko and Liquiñe-Ofqui . Insular India began to collide with Asia circa 70 Ma , forming the Indian subcontinent , since which more than 1,400 km (870 mi) of crust has been absorbed by

1010-639: A number of species related to those of the laurissilva of Valdivia, through the connection of the Antarctic flora . These include gymnosperms and the deciduous species of Nothofagus , as well as the New Zealand laurel, Corynocarpus laevigatus , and Laurelia novae-zelandiae . New Caledonia and New Zealand became separated from Australia by continental drift 85 million years ago. The islands still retain plants that originated in Gondwana and spread to

1111-616: A pale reddish-grey matrix. The rock just south of the Hartebeeskuil dam however, is composed more of partially silicified sandstone and quartzite clasts. At Mossel Bay , the Enon outcrops are often also composed of sandstone and quartzite clasts. Along the Oudshoorn-Gamtoos Basin, it occurs south of the Swartberg mountain range - around Oudtshoorn and eastwards. A large but highly eroded outcrop also occurs in

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1212-544: A pattern that reflects the Jurassic break-up of Pangaea. The Cretaceous saw the arrival of the angiosperms , or flowering plants, a group that probably evolved in western Gondwana (South America–Africa). From there the angiosperms diversified in two stages: the monocots and magnoliids evolved in the Early Cretaceous, followed by the hammamelid dicots . By the Mid-Cretaceous, angiosperms constituted half of

1313-521: A peak in biodiversity – the end-Permian extinction was enormous and so was the radiation that followed. Two families of conifers, Podocarpaceae and Araucariaceae , dominated Gondwana in the Early Triassic, but Dicroidium , an extinct genus of fork-leaved seed ferns, dominated woodlands and forests of Gondwana during most of the Triassic. Conifers evolved and radiated during the period, with six of eight extant families already present before

1414-411: A red band. An anchor was placed behind the shield. The British authorities discontinued the drostdy seals in 1814, and replaced them with the royal coat of arms. Municipality (1) – The town of Swellendam established a municipality in 1843. Some time later, the town council decided to adopt the old drostdy arms (although it was not the legal successor to the drostdy). It mistook the fleur de lis for

1515-669: A result of data sets compiled on behalf of oil and mining companies: the East African Orogeny ( 650 to 800 Ma ) and Kuunga orogeny (including the Malagasy Orogeny in southern Madagascar) ( 550 Ma ), the collision between East Gondwana and East Africa in two steps, and the Brasiliano orogeny ( 660 to 530 Ma ), the successive collision between South American and African cratons . The last stages of Gondwanan assembly overlapped with

1616-853: A series of events severally restricted the Proto-ACC: change to shallow marine conditions along the North Scotia Ridge; closure of the Fuegan Seaway, the deep sea that existed in Tierra del Fuego; and uplift of the Patagonian Cordillera. This, together with the reactivated Iceland plume , contributed to global warming. During the Miocene, the Drake Passage began to widen, and as water flow between South America and

1717-473: A sheaf of wheat, and thus actually created a new design. Municipality (2) – In 1929, the town council learned that the Swellengrebel arms actually depicted a fleur de lis and not a sheaf of wheat. It changed the municipal arms accordingly. Both arms were depicted on cigarette cards issued in 1931. Divisional council – The divisional council, i.e. the local authority for the rural areas outside

1818-694: A single jaw from Australia. The closure of the Rheic Ocean and the formation of Pangaea in the Carboniferous resulted in the rerouting of ocean currents that initiated an Ice House period. As Gondwana began to rotate clockwise, Australia shifted south to more temperate latitudes. An ice cap initially covered most of southern Africa and South America but spread to eventually cover most of the supercontinent, save for northernmost Africa-South America and eastern Australia. Giant lycopod and horsetail forests continued to evolve in tropical Laurasia together with

1919-589: A small coastal town about 50 km (30 miles) from Swellendam, is one of the best whale viewing spots on the South coast as it is the largest whale nursery in South Africa. The town is situated at the foot of the Langeberg , and there are many hiking trails, ranging from day-walks to a 5 to 7-day trail. Wheat, canola, oats, sheep and dairy farming are practised in the area. Sentraal-Suid Koöperasie serves as

2020-507: A sustainable number today. The area is botanically diverse with an abundance of wild flowers and fynbos . The 250 hectare (one square mile) indigenous forest at Grootvadersbosch is the most noteworthy in the southwestern Cape. Woods like these are rare to find in the Cape this far west of the Knysna forests . Wildlife such as the formerly endangered bontebok and Cape mountain zebra inhabit

2121-466: A useful refreshment station on the long, slow journey up the coast. Today Swellendam remains an agricultural area, and contains multiple historic buildings. The first known sketch of Swellendam was of the Drostdy, by Johannes Schumacher in 1776, when he accompanied the son of Governor Swellengrebel to the town. Today the Drostdy forms part of a museum complex that consist of several heritage sites, namely

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2222-500: A village was established beyond the Drostdy, where artisans including numerous wainwrights and traders settled. Swellendam was the last Dutch outpost on the eastern frontier, and provided useful crafts services in the region. By 1795, maladministration and inadequacies of the Dutch East India Company caused the burghers of Swellendam to revolt, and on 17 June 1795, they declared themselves a Republic. Hermanus Steyn

2323-563: Is also commonly called Gondwanaland . Regions that were part of Gondwana shared floral and zoological elements that persist to the present day. The continent of Gondwana was named by the Austrian scientist Eduard Suess , after the region in central India of the same name , which is derived from Sanskrit for "forest of the Gonds ". The name had been previously used in a geological context, first by H. B. Medlicott in 1872, from which

2424-519: Is extremely poor. Gondwana Gondwana ( / ɡ ɒ n d ˈ w ɑː n ə / ) was a large landmass, sometimes referred to as a supercontinent . The remnants of Gondwana make up around two-thirds of today's continental area, including South America , Africa , Antarctica , Australia , Zealandia , Arabia , and the Indian Subcontinent . Gondwana was formed by the accretion of several cratons (large stable blocks of

2525-818: Is now the Transantarctic Mountains ): the Antarctic Peninsula , Marie Byrd Land , Zealandia , and Thurston Island ; the Falkland Islands and Ellsworth–Whitmore Mountains (in Antarctica) were rotated 90° in opposite directions; and South America south of the Gastre Fault (often referred to as Patagonia ) was pushed westward. The history of the Africa-Antarctica break-up can be studied in great detail in

2626-576: Is now the southern Weddell Sea where initial break-up occurred during the Jurassic c. 180 to 160 Ma . Gondwana began to break up in the early Jurassic following the extensive and fast emplacement of the Karoo-Ferrar flood basalts c. 184 Ma . Before the Karoo plume initiated rifting between Africa and Antarctica , it separated a series of smaller continental blocks from Gondwana's southern, Proto-Pacific margin (along what

2727-541: Is presumed to have been linked to the subduction of cold oceanic lithosphere . During the mid to Late Cretaceous ( c.  90 million years ago ), the Andean orogeny changed significantly in character. Warmer and younger oceanic lithosphere is believed to have started to be subducted beneath South America around this time. Such kind of subduction is held responsible not only for the intense contractional deformation that different lithologies were subject to, but also

2828-591: Is situated on the N2 , approximately 220 km (140 miles) from both Cape Town and George . Early travellers and explorers who visited the Cape in the 16th century traded with the Khoikhoi people who lived on these shores and in the interior. When the Dutch East India Company established a replenishment station at the Cape in 1652, trade continued inland as far as Swellendam. In 1743, Swellendam

2929-787: The Antarctic Peninsula increased, the renewed ACC resulted in cooler global climate. Since the Eocene, the northward movement of the Australian Plate has resulted in an arc-continent collision with the Philippine and Caroline plates and the uplift of the New Guinea Highlands . From the Oligocene to the late Miocene, the climate in Australia, dominated by warm and humid rainforests before this collision, began to alternate between open forest and rainforest before

3030-886: The Antongil Block in far eastern Madagascar, the Seychelles , and the Napier and Rayner Complexes in East Antarctica ). The Azania continent (much of central Madagascar , the Horn of Africa and parts of Yemen and Arabia) was an island in the Mozambique Ocean. The continent Australia/ Mawson was still separated from India, eastern Africa, and Kalahari by c. 600 Ma , when most of western Gondwana had already been amalgamated. By c. 550 Ma, India had reached its Gondwanan position, which initiated

3131-1075: The Australian Plate are now separated by the Capricorn Plate and its diffuse boundaries. During the opening of the Indian Ocean, the Kerguelen hotspot first formed the Kerguelen Plateau on the Antarctic Plate c. 118 to 95 Ma and then the Ninety East Ridge on the Indian Plate at c. 100 Ma . The Kerguelen Plateau and the Broken Ridge , the southern end of the Ninety East Ridge, are now separated by

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3232-844: The Campbell Plateau , Chatham Rise , Lord Howe Rise , Norfolk Ridge , and New Caledonia , from West Antarctica c. 84 Ma . The opening of the South Atlantic Ocean divided West Gondwana (South America and Africa), but there is considerable debate over the exact timing of this break-up. Rifting propagated from south to north along Triassic–Early Jurassic lineaments, but intra-continental rifts also began to develop within both continents in Jurassic–Cretaceous sedimentary basins, subdividing each continent into three sub-plates. Rifting began c. 190 Ma at Falkland latitudes, forcing Patagonia to move relative to

3333-602: The Central Atlantic opened . Antarctica, the centre of the supercontinent, shared boundaries with all other Gondwana continents and the fragmentation of Gondwana propagated clockwise around it. The break-up was the result of the eruption of the Karoo-Ferrar igneous province , one of the Earth's most extensive large igneous provinces (LIP) c. 200 to 170 Ma , but the oldest magnetic anomalies between South America, Africa, and Antarctica are found in what

3434-834: The Drake Passage and the deepening of the Tasman Gateway. The oldest oceanic crust in the Drake Passage, however, is 34 to 29 Ma -old which indicates that the spreading between the Antarctic and South American plates began near the Eocene/Oligocene boundary. Deep sea environments in Tierra del Fuego and the North Scotia Ridge during the Eocene and Oligocene indicate a "Proto-ACC" opened during this period. Later, 26 to 14 Ma ,

3535-711: The Dunn family . Both Johannes Brand and Francis Reitz spent some of their childhood in the same Cape Dutch house in Swellendam. Both became presidents of the Orange Free State . The region has a predominantly Mediterranean climate . There are long summer days in January and February. During February and March, summer draws to a close, with prevailing South Easter winds. April and May are autumnal months, with milder days and occasional showers. June and July bring

3636-757: The Great American Interchange . The break-up of Gondwana can be said to continue in eastern Africa at the Afar Triple Junction , which separates the Arabian , Nubian , and Somali plates, resulting in rifting in the Red Sea and East African Rift . In the Early Cenozoic , Australia was still connected to Antarctica c. 35–40° south of its current location and both continents were largely unglaciated. A rift between

3737-401: The Himalayan - Tibetan orogen. During the Cenozoic, the orogen resulted in the construction of the Tibetan Plateau between the Tethyan Himalayas in the south and the Kunlun and Qilian mountains in the north. Later, South America was connected to North America via the Isthmus of Panama , cutting off a circulation of warm water and thereby making the Arctic colder, as well as allowing

3838-481: The Ordovician . This is the Cuyania or Precordillera terrane of the Famatinian orogeny in northwest Argentina which may have continued the line of the Appalachians southwards. Chilenia terrane accreted later against Cuyania. The collision of the Patagonian terrane with the southwestern Gondwanan occurred in the late Paleozoic. Subduction-related igneous rocks from beneath the North Patagonian Massif have been dated at 320–330 million years old, indicating that

3939-409: The Pan-African orogeny , caused the continental fragments of a much older supercontinent, Rodinia , to amalgamate. One of those orogenic belts, the Mozambique Belt , formed 800 to 650 Ma and was originally interpreted as the suture between East (India, Madagascar, Antarctica, and Australia) and West Gondwana (Africa and South America). Three orogenies were recognised during the 1990s as

4040-481: The Pangaea supercontinent during the Carboniferous. Pangaea began to break up in the Mid-Jurassic when the Central Atlantic opened . In the western end of Pangaea, the collision between Gondwana and Laurasia closed the Rheic and Palaeo-Tethys oceans. The obliquity of this closure resulted in the docking of some northern terranes in the Marathon , Ouachita , Alleghanian , and Variscan orogenies, respectively. Southern terranes, such as Chortis and Oaxaca , on

4141-499: The Southeast Indian Ridge . Separation between Australia and East Antarctica began c. 132 Ma with seafloor spreading occurring c. 96 Ma . A shallow seaway developed over the South Tasman Rise during the Early Cenozoic and as oceanic crust started to separate the continents during the Eocene c. 35.5 Ma global ocean temperature dropped significantly. A dramatic shift from arc- to rift magmatism c. 100 Ma separated Zealandia , including New Zealand ,

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4242-442: The Uralian orogeny and Laurasia . Pangaea was finally amalgamated in the Late Carboniferous-Early Permian, but the oblique forces continued until Pangaea began to rift in the Triassic. In the eastern end, collisions occurred slightly later. The North China , South China , and Indochina blocks rifted from Gondwana during the middle Paleozoic and opened the Proto-Tethys Ocean . North China docked with Mongolia and Siberia during

4343-422: The Variscan orogeny close to the Carboniferous–Permian boundary. South-east Asia was made of Gondwanan and Cathaysian continental fragments that were assembled during the Mid-Palaeozoic and Cenozoic. This process can be divided into three phases of rifting along Gondwana's northern margin: first, in the Devonian, North and South China , together with Tarim and Quidam (north-western China) rifted, opening

4444-403: The uplift and erosion known to have occurred from the Late Cretaceous onward. Plate tectonic reorganisation since the mid-Cretaceous might also have been linked to the opening of the South Atlantic Ocean . Another change related to mid-Cretaceous plate tectonic rearrangement was the change of subduction direction of the oceanic lithosphere that went from having south-east motion to having

4545-490: The Algoa Basin. Much of the formation tends to comprise smaller clasts in a more iron-rich matrix, giving it a more reddish colour. Conglomerates are the most diagnostic feature of the Enon, so much so in the past the formation was referred to as the Enon Conglomerate Formation. The conglomerates consist of large, sub-rounded to rounded clasts of sheared or unsheared quartzite and sometimes slate , shale , and charcoal . Quartzite clasts are generally more rounded whereas

4646-422: The Cape winter, with mild weather, rain and possible snow on the mountain tops. August and September are the start of spring. Three nature reserves are situated near Swellendam, Marloth Nature Reserve , Sanbona Wildlife Reserve and Bontebok National Park . Bontebok National Park is where the rare bontebok was protected when it was close to extinction. The population has increased from 17 individuals in 1931 to

4747-502: The Carboniferous–Permian, followed by South China. The Cimmerian blocks then rifted from Gondwana to form the Palaeo-Thethys and Neo-Tethys oceans in the Late Carboniferous, and docked with Asia during the Triassic and Jurassic. Western Pangaea began to rift while the eastern end was still being assembled. The formation of Pangaea and its mountains had a tremendous impact on global climate and sea levels, which resulted in glaciations and continent-wide sedimentation. In North America,

4848-414: The Drostdy, the old Gaol, and Mayville. The 1936 census recorded a total population 3,784 residents. Some of the famous families that settled in the region and have since lived there are the Barry family, the Moodies from Scotland , the Steyns (Including The President of the Republic of Swellendam ) the Streicher family, the Van Eeden family, the Rothmann family, the Tomlinson family and

4949-405: The Early Cretaceous, and West Burma and Woyla during the Late Cretaceous. Gondwana's long, northern margin remained a mostly passive margin throughout the Palaeozoic. The Early Permian opening of the Neo-Tethys Ocean along this margin produced a long series of terranes, many of which were and still are being deformed in the Himalaya Orogeny . These terranes are, from Turkey to north-eastern India:

5050-412: The Earth's crust), beginning c.   800 to 650 Ma with the East African Orogeny , the collision of India and Madagascar with East Africa, and culminating in c.   600 to 530 Ma with the overlapping Brasiliano and Kuunga orogenies, the collision of South America with Africa, and the addition of Australia and Antarctica, respectively. Eventually, Gondwana became

5151-424: The Ecca formation. In the Nuy-Vink area, it exists as pale Witteberg sandstone and greenish Ecca shale clasts, cemented in a pale red or greenish (sometimes calcareous ) mudstone, overlaying the Ecca Group and the Dwyka . Between Robertson and Ashton , it exists mainly as micaceous or quartzitic Witteberg sandstone clasts , in a reddish-brown matrix, overlaying Witteberg Group rocks. This outcrop surrounds

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5252-448: The Equator during this period and remained a lifeless and barren landscape. West Gondwana drifted north during the Devonian , bringing Gondwana and Laurasia close together. Global cooling contributed to the Late Devonian extinction (19% of marine families and 50% of genera went extinct) and glaciation occurred in South America. Before Pangaea had formed, terrestrial plants, such as pteridophytes , began to diversify rapidly resulting in

5353-400: The Equator on landmasses then limited to Laurasia and, in Gondwana, to Australia. In the late Silurian, two distinctive lineages, zosterophylls and rhyniophytes , had colonised the tropics. The former evolved into the lycopods that were to dominate the Gondwanan vegetation over a long period, whilst the latter evolved into horsetails and gymnosperms . Most of Gondwana was located far from

5454-443: The Gondwana sedimentary sequences ( Permian - Triassic ) are also described. Some scientists prefer the term "Gondwanaland" for the supercontinent to make a clear distinction between the region and the supercontinent. The assembly of Gondwana was a protracted process during the Neoproterozoic and Paleozoic , which remains incompletely understood because of the lack of paleo-magnetic data. Several orogenies , collectively known as

5555-446: The Jurassic flora was dominated by conifer families and other gymnosperms that had evolved during the Triassic. The Pteridophytes that had dominated during the Palaeozoic were now marginalised, except for ferns. In contrast to Laurentia, very few insect fossils have been found in Gondwana, to a considerable extent because of widespread deserts and volcanism. While plants had a cosmopolitan distribution, dinosaurs evolved and diversified in

5656-406: The Kuunga orogeny (also known as the Pinjarra orogeny). Meanwhile, on the other side of the newly forming Africa, Kalahari collided with Congo and Rio de la Plata which closed the Adamastor Ocean . c. 540–530 Ma, the closure of the Mozambique Ocean brought India next to Australia–East Antarctica, and both North and South China were in proximity to Australia. As the rest of Gondwana formed,

5757-422: The Late Permian, many known from South Africa and Australia. Beetles and cockroaches remained minor elements in this fauna. Tetrapod fossils from the Early Permian have only been found in Laurasia but they became common in Gondwana later during the Permian. The arrival of the therapsids resulted in the first plant-vertebrate-insect ecosystem. During the Mid- to Late Triassic, hot-house conditions coincided with

5858-405: The Miocene, a warm and humid climate developed with pockets of rainforests in central Australia, but before the end of the period, colder and drier climate severely reduced this rainforest. A brief period of increased rainfall in the Pliocene was followed by drier climate which favoured grassland. Since then, the fluctuation between wet interglacial periods and dry glacial periods has developed into

5959-443: The Neoproterozoic to Palaeozoic phase of the Terra Australis Orogen , a series of terranes were rafted from the proto-Andean margin when the Iapteus Ocean opened, to be added back to Gondwana during the closure of that ocean. During the Paleozoic, some blocks which helped to form parts of the Southern Cone of South America, include a piece transferred from Laurentia when the west edge of Gondwana scraped against southeast Laurentia in

6060-441: The Palaeo-Tethys behind them. These terranes accreted to Asia during Late Devonian and Permian. Second, in the Late Carboniferous to Early Permian, Cimmerian terranes opened Meso-Tethys Ocean; Sibumasu and Qiangtang were added to south-east Asia during Late Permian and Early Jurassic. Third, in the Late Triassic to Late Jurassic, Lhasa , West Burma , Woyla terranes opened the Neo-Tethys Ocean; Lhasa collided with Asia during

6161-456: The South Atlantic (Brazil and Cameroon ) dating to around 120  million years ago , suggesting that some form of land connection still existed between Africa and South America as recently as the early Aptian . The first phases of Andean orogeny in the Jurassic and Early Cretaceous were characterised by extensional tectonics , rifting , the development of back-arc basins and the emplacement of large batholiths . This development

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6262-426: The Southern Hemisphere continents later. [REDACTED] Africa Swellendam Swellendam ( Afrikaans: ['swæːləndam] ) is the third oldest town in South Africa (after Cape Town and Stellenbosch ), a town with 17,537 inhabitants situated in the Western Cape province. The town has over 50 provincial heritage sites , most of them buildings of Cape Dutch architecture. Swellendam

6363-465: The Southern Hemisphere, has a "Gondwanan distribution" and is often described as an archaic, or relict , lineage. The distributions in the Proteaceae is, nevertheless, the result of both Gondwanan rafting and later oceanic dispersal. During the Silurian, Gondwana extended from the Equator (Australia) to the South Pole (North Africa and South America) whilst Laurasia was located on the Equator opposite to Australia. A short-lived Late Ordovician glaciation

6464-404: The Soutpansvlakte Basin, in the Waterskilpad river area, north east of Bredasdorp . The far western portion of this conglomerate is composed of Bokkeveld (60%) and Table Mountain sandstone (40%) clasts. The more northern parts have far more intercalated sandstone and mudstone, with clasts originating from the central Ruens Bokkeveld deposits. The clasts of the southern parts are predominantly from

6565-408: The Taurides in southern Turkey; the Lesser Caucasus Terrane in Georgia; the Sanand, Alborz, and Lut terranes in Iran; the Mangysglak or Kopetdag Terrane in the Caspian Sea; the Afghan Terrane; the Karakorum Terrane in northern Pakistan; and the Lhasa and Qiangtang terranes in Tibet. The Permian–Triassic widening of the Neo-Tethys pushed all these terranes across the Equator and over to Eurasia. During

6666-439: The Worcester-Pletmos Basin, it occurs in patches along the southern flanks of the Langeberg Mountains - from Worcester in the west, as far as Mossel Bay in the east. In the Breede River valley , the Enon beds are tilted downwards to the south, and occur in three main outcrops. At Worcester it exists as partially-rounded clasts of grit and Witteberg sandstone, cemented in beds of argillaceous, reddish sandstone, and overlaying

6767-403: The area. Other species include bushbuck , klipspringer , grey rhebuck , Cape grysbok , baboon , mongoose , genet and the occasional leopard , as well as a species of ghost frog and a unique forest emperor butterfly. Over 200 bird species found near the town include waterfowl, the crowned eagle , black eagle , Narina trogon , paradise flycatcher and the Knysna woodpecker . Witsand ,

6868-550: The base of the Absaroka sequence coincides with the Alleghanian and Ouachita orogenies and are indicative of a large-scale change in the mode of deposition far away from the Pangaean orogenies. Ultimately, these changes contributed to the Permian–Triassic extinction event and left large deposits of hydrocarbons, coal, evaporite, and metals. The breakup of Pangaea began with the Central Atlantic magmatic province (CAMP) between South America, Africa, North America, and Europe. CAMP covered more than seven million square kilometres over

6969-414: The colonisation of Gondwana. The Baragwanathia Flora, found only in the Yea Beds of Victoria, Australia, occurs in two strata separated by 1,700 m (5,600 ft) or 30 Ma; the upper assemblage is more diverse and includes Baragwanathia, the first primitive herbaceous lycopod to evolve from the zosterophylls. During the Devonian, giant club mosses replaced the Baragwanathia Flora, introducing

7070-492: The continent Kazakhstania in the late Silurian . Whether these blocks originated on the shores of Gondwana is not known. In the Early Palaeozoic, the Armorican terrane , which today form large parts of France, was part of either Peri-Gondwana or core Gondwana; the Rheic Ocean closed in front of it and the Palaeo-Tethys Ocean opened behind it. Precambrian rocks from the Iberian Peninsula suggest that it, too, formed part of core Gondwana before its detachment as an orocline in

7171-424: The continent became the arid or semiarid landscape it is today. The adjective "Gondwanan" is in common use in biogeography when referring to patterns of distribution of living organisms, typically when the organisms are restricted to two or more of the now-discontinuous regions that were once part of Gondwana, including the Antarctic flora . For example, the plant family Proteaceae , known from all continents in

7272-833: The development of rifts systems on both continents, including the Central African Rift System and the Central African Shear Zone which lasted until c. 85 Ma . At Brazilian latitudes spreading is more difficult to assess because of the lack of palaeo-magnetic data, but rifting occurred in Nigeria at the Benue Trough c. 118 Ma . North of the Equator the rifting began after 120.4 Ma and continued until c. 100 to 96 Ma . Dinosaur footprints representing identical species assemblages are known from opposite sides of

7373-556: The end of it. Bennettitales and Pentoxylales , two now extinct orders of gymnospermous plants, evolved in the Late Triassic and became important in the Jurassic and Cretaceous. It is possible that gymnosperm biodiversity surpassed later angiosperm biodiversity and that the evolution of angiosperms began during the Triassic but, if so, in Laurasia rather than in Gondwana. Two Gondwanan classes, lycophytes and sphenophytes , saw

7474-946: The eruption of the Deccan basalts , whose eruption site may survive as the Réunion hotspot . The Seychelles and the Maldives are now separated by the Central Indian Ridge . During the initial break-up in the Early Jurassic a marine transgression swept over the Horn of Africa covering Triassic planation surfaces with sandstone , limestone , shale , marls and evaporites . East Gondwana, comprising Antarctica, Madagascar, India, and Australia, began to separate from Africa. East Gondwana then began to break up c. 132.5 to 96 Ma when India moved northwest from Australia-Antarctica. The Indian Plate and

7575-563: The evolution of Voltziales , one of the few plant orders to survive the end-Permian extinction (57% of marine families and 83% of genera went extinct) and which came to dominate in the Late Permian and from whom true conifers evolved. Tall lycopods and horsetails dominated the wetlands of Gondwana in the Early Permian. Insects co-evolved with glossopterids across Gondwana and diversified with more than 200 species in 21 orders by

7676-670: The fine, pale, greyish Kirkwood Formation sandstones of the Klaasvoogdsrivier area. The eastern part of this Enon outcrop, near Ashton, contains clasts of Dwyka tillite, fine greenish sandstone and shale pebbles. In the Overberg region, the Enon Formation occurs in several more outcrops. At Swellendam , it exists as Bokkeveld shale and micaceous Witteberg sandstone clasts, in a reddish-green sandy clay matrix. Between Heidelberg and Riversdale , it exists mainly as

7777-564: The first amniote reptilians evolved, all closely related to the Laurasian fauna, but spreading ice eventually drove these animals away from Gondwana entirely. The Gondwana ice sheet melted, and sea levels dropped during the Permian and Triassic global warming. During this period, the extinct glossopterids colonised Gondwana and reached peak diversity in the Late Permian when coal-forming forests covered much of Gondwana. The period also saw

7878-522: The first trees, and by the Late Devonian this first forest was accompanied by the progymnosperms , including the first large trees Archaeopteris . The Late Devonian extinction probably also resulted in osteolepiform fishes evolving into the amphibian tetrapods , the earliest land vertebrates, in Greenland and Russia. The only traces of this evolution in Gondwana are amphibian footprints and

7979-526: The flora in northeastern Australia. There is, however, no obvious connection between this spectacular angiosperm radiation and any known extinction event nor with vertebrate/insect evolution. Insect orders associated with pollination, such as beetles , flies , butterflies and moths , and wasps, bees, and ants , radiated continuously from the Permian-Triassic, long before the arrival of the angiosperms. Well-preserved insect fossils have been found in

8080-636: The fracture zones and magnetic anomalies flanking the Southwest Indian Ridge . The Madagascar block and the Mascarene Plateau , stretching from the Seychelles to Réunion , were broken off India, causing Madagascar and Insular India to be separate landmasses : elements of this break-up nearly coincide with the Cretaceous–Paleogene extinction event . The India–Madagascar–Seychelles separations appear to coincide with

8181-861: The lake deposits of the Santana Formation in Brazil, the Koonwarra Lake fauna in Australia, and the Orapa diamond mine in Botswana. Dinosaurs continued to prosper but, as the angiosperm diversified, conifers, bennettitaleans and pentoxylaleans disappeared from Gondwana c. 115 Ma together with the specialised herbivorous ornithischians , whilst generalist browsers, such as several families of sauropodomorph Saurischia , prevailed. The Cretaceous–Paleogene extinction event killed off all dinosaurs except birds, but plant evolution in Gondwana

8282-700: The largest piece of continental crust of the Palaeozoic Era, covering an area of some 100,000,000 km (39,000,000 sq mi), about one-fifth of the Earth's surface. It fused with Euramerica during the Carboniferous to form Pangea . It began to separate from northern Pangea ( Laurasia ) during the Triassic , and started to fragment during the Early Jurassic (around 180 million years ago). The final stages of break-up, involving

8383-610: The limits of the Enon conglomerate beds often interfinger or transition gradually into the softer sands and mudstones of the Kirkwood Formation . Outcroups are also known from the Breede River Valley. Some silicified wood , charcoal fragments, abraded bone fragments, and two theropod dinosaur teeth, have been recovered from the Enon Formation at the Oudtshoorn theropod site. However, fossil preservation

8484-416: The most common matrix is a gypsiferous (sometimes iron-oxide rich) sandy clay. At some places, clasts of various sizes are intermixed, with large amounts of sandy matrix; at others however, water-sorted clasts of similar size occur in layers, separated by infilled sandstone lenses. Groupings within the formation have occasionally been informally identified, such as the basal Enon Sandstones that occur in

8585-701: The opening of the Iapetus Ocean between Laurentia and western Gondwana. During this interval, the Cambrian explosion occurred. Laurentia was docked against the western shores of a united Gondwana for a brief period near the Precambrian/Cambrian boundary, forming the short-lived and still disputed supercontinent Pannotia . The Mozambique Ocean separated the Congo – Tanzania – Bangweulu Block of central Africa from Neoproterozoic India (India,

8686-600: The other hand, remained largely unaffected by the collision along the southern shores of Laurentia. Some Peri-Gondwanan terranes, such as Yucatán and Florida , were buffered from collisions by major promontories. Other terranes, such as Carolina and Meguma , were directly involved in the collision. The final collision resulted in the Variscan- Appalachian Mountains , stretching from present-day Mexico to southern Europe. Meanwhile, Baltica collided with Siberia and Kazakhstania which resulted in

8787-561: The present arid regime. Australia has thus experienced various climate changes over a 15-million-year period with a gradual decrease in precipitation. The Tasman Gateway between Australia and Antarctica began to open c. 40 to 30 Ma . Palaeontological evidence indicates the Antarctic Circumpolar Current (ACC) was established in the Late Oligocene c. 23 Ma with the full opening of

8888-760: The remaining Gondwana c. 570 to 530 Ma in the Kuunga Orogeny. The later Malagasy orogeny at about 550–515 Mya affected Madagascar, eastern East Africa and southern India. In it, Neoproterozoic India collided with the already combined Azania and Congo–Tanzania–Bangweulu Block, suturing along the Mozambique Belt. The 18,000 km-long (11,000 mi) Terra Australis Orogen developed along Gondwana's western, southern, and eastern margins. Proto-Gondwanan Cambrian arc belts from this margin have been found in eastern Australia, Tasmania, New Zealand, and Antarctica. Though these belts formed

8989-538: The separation of Antarctica from South America (forming the Drake Passage ) and Australia, occurred during the Paleogene (from around 66 to 23 million years ago (Ma)). Gondwana was not considered a supercontinent by the earliest definition, since the landmasses of Baltica , Laurentia , and Siberia were separated from it. To differentiate it from the Indian region of the same name (see § Name ), it

9090-403: The slate and shale clasts are angular. These are interbedded with subordinate sandstone lenses ranging from white, yellow, red and green in colour, claystones , and rare mudstone units. These were deposited in a high-energy alluvial environment where debris flows were common. Though formerly continuous, the Enon Formation now occurs as several disjunct outcrops in the southern Cape. Along

9191-665: The still static remainder of South America and Africa, and this westward movement lasted until the Early Cretaceous 126.7 Ma . From there rifting propagated northward during the Late Jurassic c. 150 Ma or Early Cretaceous c. 140 Ma most likely forcing dextral movements between sub-plates on either side. South of the Walvis Ridge and Rio Grande Rise the Paraná and Etendeka magmatics resulted in further ocean-floor spreading c. 130 to 135 Ma and

9292-399: The subduction process initiated in the early Carboniferous. This was relatively short-lived (lasting about 20 million years), and initial contact of the two landmasses occurred in the mid-Carboniferous, with broader collision during the early Permian. In the Devonian, an island arc named Chaitenia accreted to Patagonia in what is now south-central Chile. Gondwana and Laurasia formed

9393-521: The surrounding Bredasdorp mountains and Bokkeveld rocks. To the east, an isolated bed in the Soutrivier valley is composed almost entirely of disc-shaped shale and siltstone clasts (with occasional vein quartz rocks). Other outcrops occur in smaller, isolated basins south of Soetendalsvlei at Jubilee, where pale red and grey conglomerates, mudstones, sandstones and tuffaceous rocks support occasional silcrete caps, as well as at Haasvlakte. Laterally,

9494-513: The town, assumed its own coat of arms on 15 November 1974. and registered it at the Bureau of Heraldry in October 1975. The arms – Per pale Azure and Or, a fleur-de-lis and in chief two mullets of six points counterchanged , i.e. a shield divided vertically into blue and gold, and a fleur de lis below two six-pointed stars – were designed by Cornelis Pama . The crest was an anchor entwined with

9595-636: The two developed but remained an embayment until the Eocene-Oligocene boundary when the Circumpolar Current developed and the glaciation of Antarctica began. Australia was warm and wet during the Palaeocene and dominated by rainforest. The opening of the Tasman Gateway at the Eocene-Oligocene boundary ( 33 Ma ) resulted in abrupt cooling but the Oligocene became a period of high rainfall with swamps in southeast Australia. During

9696-739: The younger and softer formations - the Kirkwood and Sundays River - which overlie it, and because it is the oldest formation of the onshore post-Karoo Mesozoic deposits found in South Africa . Underlying strata are separated by unconformities in most locales expect where the Enon is underlain by deposits of the Cape Fold Belt. The sedimentary rock of the Enon comprises several different types of coarse, clastic , poorly sorted pebble to cobble thickly-bedded conglomerate deposits . The clasts are usually pale or white quartzite , and

9797-638: Was appointed as President of the Republic of Swellendam . The burghers of Swellendam started to call themselves "national burghers", after the style of the French Revolution. The Republic was short-lived, and was ended on 4 November 1795, when the Cape was occupied by the Kingdom of Great Britain . With the arrival of British settlers in the early 19th century, the Overberg boomed, and Swellendam

9898-461: Was declared a magisterial district, the third-oldest in South Africa, and was named after Governor Hendrik Swellengrebel , the first South African born Governor, and his wife, Helena Ten Damme. This outlying settlement soon became a gateway to the interior, and was visited by many famous explorers and travellers including François Le Vaillant (1781), Lady Anne Barnard (1798), William John Burchell (1815), and Thomas William Bowler (1860). In time,

9999-483: Was followed by a Silurian Hot House period. The End-Ordovician extinction , which resulted in 27% of marine invertebrate families and 57% of genera going extinct, occurred during this shift from Ice House to Hot House. By the end of the Ordovician, Cooksonia , a slender, ground-covering plant, became the first known vascular plant to establish itself on land. This first colonisation occurred exclusively around

10100-540: Was hardly affected. Gondwanatheria is an extinct group of non- therian mammals with a Gondwanan distribution (South America, Africa, Madagascar, India, Zealandia and Antarctica) during the Late Cretaceous and Palaeogene. Xenarthra and Afrotheria , two placental clades, are of Gondwanan origin and probably began to evolve separately c. 105 Ma when Africa and South America separated. The laurel forests of Australia, New Caledonia, and New Zealand have

10201-509: Was soon the heart of the mercantile empire of Barry and Nephews, created by Joseph Barry, which dominated trade in the area up until 1870. The Breede River is the longest navigable river in South Africa and ships sailed 35 km (20 miles) up river to Malgas to unload and load merchandise. By the middle of the 19th century, the eastern districts had been colonised by the British settlers and Swellendam had grown in size. The town served as

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