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Gondwana

Gondwana ( /ɡɒndˈwɑːnə/)[1] was a large landmass, sometimes referred to as a supercontinent. It was formed by the accretion of several cratons (large stable blocks of 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.[2] Eventually, Gondwana became the largest piece of continental crust of the Palaeozoic Era, covering an area of some 100,000,000 km2 (39,000,000 sq mi),[3] 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 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 (Mya). Gondwana was not considered a supercontinent by the earliest definition, since the landmasses of Baltica, Laurentia, and Siberia were separated from it.[4] To differentiate it from the Indian region of the same name (see § Name), it is also commonly called Gondwanaland.[5]

Gondwana
Gondwana 420 million years ago (late Silurian). View centred on the South Pole.
Historical continent
Formed600 Mya
TypeSupercontinent
Today part ofAfrica
North America
South America
Australia
India
Arabia
Antarctica
Balkans
Smaller continentsSouth America
Africa
Australia
Antarctica
Zealandia
Tectonic platesAfrican Plate
Antarctic Plate
Indo-Australian Plate
South American Plate

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.

Regions that were part of Gondwana shared floral and zoological elements that persist to the present day.

Name edit

 
Distribution of four Permian and Triassic fossil groups used as biogeographic evidence for continental drift, and land bridging

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".[6] The name had been previously used in a geological context, first by H. B. Medlicott in 1872,[7] from which the Gondwana sedimentary sequences (Permian-Triassic) are also described.

Some scientists prefer the term "Gondwanaland" to make a clear distinction between the region and the supercontinent.[8]

Formation edit

 
Eastern Gondwana. 620 to 550 Ma post-collisional extension of the East African Orogeny in blue and 570 to 530 Ma collisional metamorphism of the Kuunga orogeny in red.[9]

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 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: 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.[10]

The last stages of Gondwanan assembly overlapped with the opening of the Iapetus Ocean between Laurentia and western Gondwana.[11] 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.[12]

The Mozambique Ocean separated the CongoTanzaniaBangweulu Block of central Africa from Neoproterozoic India (India, the Antongil Block in far eastern Madagascar, the Seychelles, and the Napier and Rayner Complexes in East Antarctica). The Azania continent[13] (much of central Madagascar, the Horn of Africa and parts of Yemen and Arabia) was an island in the Mozambique Ocean.

 
Reconstruction showing final stages of assembly of Gondwana, 550 Mya

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 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.[14]

As the rest of Gondwana formed, 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 the remaining Gondwana c. 570 to 530 Ma in the Kuunga Orogeny.[15]

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.[16]

The 18,000 km-long (11,000 mi) Terra Australis Orogen developed along Gondwana's western, southern, and eastern margins.[17] Proto-Gondwanan Cambrian arc belts from this margin have been found in eastern Australia, Tasmania, New Zealand, and Antarctica. Though these belts formed a continuous arc chain, the direction of subduction was different between the Australian-Tasmanian and New Zealand-Antarctica arc segments.[18]

Peri-Gondwana development: Paleozoic rifts and accretions edit

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 the continent Kazakhstania in the Late Silurian. Whether these blocks originated on the shores of Gondwana is not known.[19]

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 the Variscan orogeny close to the Carboniferous–Permian boundary.[20]

 
 
 
 
Journey of the Asian blocks from Gondwana to Laurasia, Late Ordovician to Early Jurassic (450, 350, 300, and 200 Mya).
View centred on 0°S,105°E.

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 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 the Early Cretaceous, and West Burma and Woyla during the Late Cretaceous.[21]

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: 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.[22]

Southwestern accretions edit

During 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.[23] 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 the Ordovician.[24] This is the Cuyania or Precordillera terrane of the Famatinian orogeny in northwest Argentina which may have continued the line of the Appalachians southwards.[25] Chilenia terrane accreted later against Cuyania.[26] 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 the subduction process initiated in the early Carboniferous.[27] This was relatively short lived (lasting about 20 million years), and initial contact of the two landmasses occurred in the mid-Carboniferous,[27][28] with broader collision during the early Permian.[28] In the Devonian, an island arc named Chaitenia accreted to Patagonia in what is now south-central Chile.[29]

Gondwana as part of Pangaea: Late Paleozoic to Early Mesozoic edit

 
Gondwana formed part of Pangaea for c. 150 Ma[30]

Gondwana and Laurasia formed the Pangaea supercontinent during the Carboniferous. Pangaea began to break up in the Mid-Jurassic when the Central Atlantic opened.[31]

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 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 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.[32]

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 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.[33]

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, 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.[34]

The break-up 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 a few million years, reached its peak at c. 200 Ma, and coincided with the Triassic–Jurassic extinction event.[35] 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 the Central Atlantic opened.[36]

Break-up edit

Mesozoic edit

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 is now the southern Weddell Sea where initial break-up occurred during the Jurassic c. 180 to 160 Ma.[37]

Opening of western Indian Ocean edit

 
 
The first ocean floor formed between Madagascar and Africa c. 150 Ma (left) and between India and Madagascar c. 70 Ma (right).

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 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.[38] The history of the Africa-Antarctica break-up can be studied in great detail in the fracture zones and magnetic anomalies flanking the Southwest Indian Ridge.[39]

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 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.[40][41]

Opening of eastern Indian Ocean edit

 
 
 
The first ocean floor formed between India and Antarctica c. 120 Ma (left). The Kerguelen LIP began to form the Ninety East ridge c. 80 Ma (centre). The Indian and Australian plates merged c. 40 Ma (right).

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.[42] The Indian Plate and the Australian Plate are now separated by the Capricorn Plate and its diffuse boundaries.[43] 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.[44] The Kerguelen Plateau and the Broken Ridge, the southern end of the Ninety East Ridge, are now separated by 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.[45] A dramatic shift from arc- to rift magmatism c. 100 Ma separated Zealandia, including New Zealand, the Campbell Plateau, Chatham Rise, Lord Howe Rise, Norfolk Ridge, and New Caledonia, from West Antarctica c. 84 Ma.[46]

Opening of South Atlantic Ocean edit

 
 
At c. 126 Ma (left) the Falkland Plateau began to slide past southern Africa and the Paraná-Etendeka LIP had opened the Mid-Atlantic Ridge. At c. 83 Ma (right) the South Atlantic was fully opened and the Romanche Fracture Zone was forming near the Equator.

The opening of the South Atlantic Ocean divided West Gondwana (South America and Africa), but there is a 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 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 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.[47]

Early Andean orogeny edit

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.[48][49] This development is presumed to have been linked to the subduction of cold oceanic lithosphere.[49] During the mid to Late Cretaceous (c. 90 million years ago), the Andean orogeny changed significantly in character.[48][49] 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 the uplift and erosion known to have occurred from the Late Cretaceous onward.[49] Plate tectonic reorganisation since the mid-Cretaceous might also have been linked to the opening of the South Atlantic Ocean.[48] 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 a north-east motion at about 90 million years ago.[50] 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.[49][50]

Cenozoic edit

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 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.[51]

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,[52] as well as allowing 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.[53]

Australia–Antarctica separation edit

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 the two developed but remained an embayment until the Eocene-Oligocene boundary when the Circumpolar Current developed and the glaciation of Antarctica began.[54]

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 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 the present arid regime. Australia has thus experienced various climate changes over a 15-million-year period with a gradual decrease in precipitation.[55]

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 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.[56] 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, 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 the Antarctic Peninsula increased, the renewed ACC resulted in cooler global climate.[57]

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.[58] 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 the continent became the arid or semiarid landscape it is today.[59]

Biogeography edit

 
Banksia, a grevilleoid Proteaceae, is an example of a plant from a family with a Gondwanan distribution

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.[8] For example, the plant family Proteaceae, known from all continents in 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.[60]

Post-Cambrian diversification edit

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 was followed by a Silurian Hot House period.[61] 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.[62]

 
 
Reconstructions of (left) a Late Silurian Cooksonia, the first land plant, and (right) a Late Devonian Archaeopteris, the first large tree

By the end of the Ordovician, Cooksonia, a slender, ground-covering plant, became the first vascular plant to establish itself on land. This first colonisation occurred exclusively around 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 the Equator during this period and remained a lifeless and barren landscape.[63]

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 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 the first trees, and by the Late Devonian this first forest was accompanied by the progymnosperms, including the first large trees Archaeopteris.[64] 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 a single jaw from Australia.[65]

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 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 the first amniote reptilians evolved, all closely related to the Laurasian fauna, but spreading ice eventually drove these animals away from Gondwana entirely.[66]

 
 
Fossilised Walchia and Utrechtia, two voltzialean pines from which modern conifers evolved
 
 
 
 
Still extant Triassic conifers (Agathis, Wollemia, Araucaria, and Podocarpus) that once dominated Gondwana

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 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 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.[67]

Modern diversification edit

During the Mid- to Late Triassic, hot-house conditions coincided with 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 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 a gradual decline during the Triassic while ferns, though never dominant, managed to diversify.[68]

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, 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 a pattern that reflects the Jurassic break-up of Pangaea.[69]

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 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 the lake deposits of the Santana Formation in Brazil, the Koonwarra Lake fauna in Australia, and the Orapa diamond mine in Botswana.[70]

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 was hardly affected.[70] 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.[71] 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.[72]

 
The plant genus Nothofagus provides a good example of a taxon with a Gondwanan distribution, having originated in the supercontinent and existing in present-day Australia, New Zealand, New Caledonia, and South America's Southern Cone. Fossils have also been found in Antarctica.[73]

The laurel forests of Australia, New Caledonia, and New Zealand have 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 the Southern Hemisphere continents later.

See also edit

References edit

Notes edit

  1. ^ "Gondwana". Dictionary.com. Lexico Publishing Group. Retrieved 18 January 2010.
  2. ^ Meert & Van der Voo 1997, Abstract
  3. ^ Torsvik & Cocks 2013, Abstract
  4. ^ Bradley, D.C. (2011). "Secular Trends in the Geologic Record and the Supercontinent Cycle". Earth-Science Reviews. 108 (1–2): 16–33. Bibcode:2011ESRv..108...16B. CiteSeerX 10.1.1.715.6618. doi:10.1016/j.earscirev.2011.05.003. S2CID 140601854.
  5. ^ "Gondwanaland". Merriam-Webster Online Dictionary. Retrieved 18 January 2010.
  6. ^ Chakrabarti, Pratik (2019). "Gondwana and the Politics of Deep Past". Past & Present. 242 (1): 119–153. doi:10.1093/pastj/gty016.
  7. ^ Suess 1885, p. 768: "Wir nennen es Gondwána-Land, nach der gemeinsamen alten Gondwána-Flora, … "(We name it Gondwána-Land, after the common ancient flora of Gondwána …)
  8. ^ a b McLoughlin 2001, Gondwana or Gondwanaland?, pp. 272–273
  9. ^ Meert 2003, Fig. 10, p. 19
  10. ^ Meert & Van der Voo 1997, Introduction, pp. 223–226
  11. ^ Miashita & Yamamoto 1996
  12. ^ Meert & Van der Voo 1997, p. 229
  13. ^ Defined but not named in Collins & Pisarevsky 2005: "Azania" was a Greek name for the East African coast
  14. ^ Li et al. 2008, The birth of Gondwanaland (600–530 Ma), p. 201
  15. ^ Meert 2003, Abstract
  16. ^ Grantham, Maboko & Eglington 2003
  17. ^ Cawood 2005, Definition and Tectonic Framework, pp. 4–6
  18. ^ Münker & Crawford 2000, Abstract
  19. ^ Torsvik & Cocks 2013, Marginal microcontinents and terranes, p. 1008
  20. ^ Torsvik & Cocks 2013, Southern Europe, pp. 1008–1009
  21. ^ McLoughlin 2001, Cimmerian terranes, p. 278
  22. ^ Torsvik & Cocks 2013, South-central and eastern Asia
  23. ^ Cawood 2005, Peri-Gondwanan continental basement assemblages, pp. 15–16
  24. ^ Rapalini 2001; Rapalini 1998, pp. 105–106
  25. ^ Dalla Salda et al. 1998, Abstract; Vujovich, van Staal & Davis 2004, Conclusions, p. 1053
  26. ^ Ramos, V.A.; Jordan, T.E.; Allmendinger, R.W.; Mpodozis, C.; Kay, S.M.; Cortés, J.M.; Palma, M. (October 1986). "Paleozoic terranes of the central Argentina-Chilean Andes". Tectonics. 5 (6): 855–880. Bibcode:1986Tecto...5..855R. doi:10.1029/TC005i006p00855.
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  29. ^ Hervé, Francisco; Calderón, Mauricio; Fanning, Mark; Pankhurst, Robert; Rapela, Carlos W.; Quezada, Paulo (2018). "The country rocks of Devonian magmatism in the North Patagonian Massif and Chaitenia". Andean Geology. 45 (3): 301–317. doi:10.5027/andgeoV45n3-3117. hdl:11336/81577.
  30. ^ Li et al. 2008, Abstract
  31. ^ Torsvik & Van der Voo 2002, Data selection and reconstruction fits, p. 772
  32. ^ Blakey 2003, Assembly of Western Pangaea: Carboniferous–Permian, pp. 453–454
  33. ^ Blakey 2003, Assembly of Eastern Pangaea: Late Permian–Jurassic, p. 454
  34. ^ Blakey 2003, Summary: significance of Pangaean events, pp. 454–455
  35. ^ Marzoli et al. 1999, Abstract
  36. ^ "Gondwana Remnants in Alabama And Georgia: Uchee Is An 'Exotic' Peri-Gondwanan Arc Terrane, Not Part of Laurentia". ScienceDaily. 4 February 2008. Retrieved 22 October 2011.
  37. ^ Jokat et al. 2003, Introduction, pp. 1–2
  38. ^ Encarnación et al. 1996, Early rifting and Gondwana breakup, pp. 537–538
  39. ^ Royer et al. 1988, Figg. 7 a–j, pp. 248–257
  40. ^ Abbate, Ernesto; Bruni, Piero; Sagri, Mario (2015). "Geology of Ethiopia: A Review and Geomorphological Perspectives". In Billi, Paolo (ed.). Landscapes and Landforms of Ethiopia. World Geomorphological Landscapes. pp. 33–64. doi:10.1007/978-94-017-8026-1_2. ISBN 978-94-017-8026-1.
  41. ^ Coltorti, M.; Dramis, F.; Ollier, C.D. (2007). "Planation surfaces in Northern Ethiopia". Geomorphology. 89 (3–4): 287–296. Bibcode:2007Geomo..89..287C. doi:10.1016/j.geomorph.2006.12.007.
  42. ^ Powell, Roots & Veevers 1988, Abstract
  43. ^ DeMets, Gordon & Royer 2005, Introduction; Fig. 1, p. 446
  44. ^ Müller, Royer & Lawver 1993, Model results, pp. 277–278
  45. ^ McLoughlin 2001, East Antarctica–Australia, p. 280
  46. ^ McLoughlin 2001, West Antarctica–Tasmania, p. 280
  47. ^ Seton et al. 2012, South Atlantic, pp. 217–218
  48. ^ a b c Ramos 2009, Abstract
  49. ^ a b c d e Charrier, Pinto & Rodríguez 2006, pp. 45–46
  50. ^ a b Hoffmann-Rothe et al. 2006
  51. ^ Yin & Harrison 2000, Abstract
  52. ^ Luyendyk, Forsyth & Phillips 1972, Abstract
  53. ^ Jestin, Huchon & Gaulier 1994, Abstract
  54. ^ Martin 2006, Palaeogeography, pp. 538–539
  55. ^ Martin 2006, Conclusions, pp. 557–558
  56. ^ Lagabrielle et al. 2009, Timing of opening of the Drake Passage region, pp. 198–199
  57. ^ Lagabrielle et al. 2009, Conclusions, p. 210
  58. ^ Hill & Hall 2003, Abstract
  59. ^ Travouillon et al. 2009, Abstract
  60. ^ Barker et al. 2007, Abstract
  61. ^ Anderson et al. 1999, SILURIAN: terrestrial life appears in the tropics, p. 148
  62. ^ Anderson et al. 1999, The First Extinction, p. 151
  63. ^ Anderson et al. 1999, The Silurian revolution, p. 151
  64. ^ Anderson et al. 1999, DEVONIAN: colonising Gondwana; The Second Extinction; Global colonisation of plants, pp. 151, 153
  65. ^ Anderson et al. 1999, Amphibian prelude, p. 153
  66. ^ Anderson et al. 1999, CARBONIFEROUS: competing with ice, pp. 153–154
  67. ^ Anderson et al. 1999, PERMIAN: the glossopterid empire, pp. 153–154
  68. ^ Anderson et al. 1999, TRIASSIC: the gymnosperm heyday, pp. 155–156
  69. ^ Anderson et al. 1999, JURASSIC: volcanism, conifers and bennettitaleans, pp. 156, 158
  70. ^ a b Anderson et al. 1999, Cretaceous: of flowers and pollination, pp. 158–159
  71. ^ Gurovich & Beck 2009, Introduction, pp. 25–26
  72. ^ Woodburne, Rich & Springer 2003, Gondwana and early mammal evolution, p. 375
  73. ^ HaoMin & ZheKun 2007

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External links edit

  • Houseman, Greg. "Animation of the dispersal of Gondwanaland". University of Leeds. Retrieved 21 October 2008.
  • Barend Köbben; Colin Reeves; Maarten de Wit. "Interactive animation of the breakup of Gondwana". ITC, University of Twente. Retrieved 16 October 2017.
  • Graphical subjects dealing with Tectonics and Paleontology
  • Gondwana Reconstruction and Dispersion
  • The Gondwana Map Project 20 September 2019 at the Wayback Machine
  • van Hinsbergen, Douwe J.J.; Torsvik, Trond H.; Schmid, Stefan M.; Maţenco, Liviu C.; Maffione, Marco; Vissers, Reinoud L.M.; Gürer, Derya; Spakman, Wim (September 2019). "Orogenic architecture of the Mediterranean region and kinematic reconstruction of its tectonic evolution since the Triassic". Gondwana Research. 81: 79–229. Bibcode:2020GondR..81...79V. doi:10.1016/j.gr.2019.07.009. hdl:20.500.11850/390104.

gondwana, this, article, about, supercontinent, region, india, india, other, uses, disambiguation, ɑː, large, landmass, sometimes, referred, supercontinent, formed, accretion, several, cratons, large, stable, blocks, earth, crust, beginning, with, east, africa. This article is about the supercontinent For the region in India see Gondwana India For other uses see Gondwana disambiguation Gondwana ɡ ɒ n d ˈ w ɑː n e 1 was a large landmass sometimes referred to as a supercontinent It was formed by the accretion of several cratons large stable blocks of 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 2 Eventually Gondwana became the largest piece of continental crust of the Palaeozoic Era covering an area of some 100 000 000 km2 39 000 000 sq mi 3 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 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 Mya Gondwana was not considered a supercontinent by the earliest definition since the landmasses of Baltica Laurentia and Siberia were separated from it 4 To differentiate it from the Indian region of the same name see Name it is also commonly called Gondwanaland 5 GondwanaGondwana 420 million years ago late Silurian View centred on the South Pole Historical continentFormed600 MyaTypeSupercontinentToday part ofAfricaNorth AmericaSouth AmericaAustraliaIndiaArabiaAntarcticaBalkansSmaller continentsSouth AmericaAfricaAustraliaAntarcticaZealandiaTectonic platesAfrican PlateAntarctic PlateIndo Australian PlateSouth American PlateThe 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 Regions that were part of Gondwana shared floral and zoological elements that persist to the present day Contents 1 Name 2 Formation 3 Peri Gondwana development Paleozoic rifts and accretions 3 1 Southwestern accretions 4 Gondwana as part of Pangaea Late Paleozoic to Early Mesozoic 5 Break up 5 1 Mesozoic 5 1 1 Opening of western Indian Ocean 5 1 2 Opening of eastern Indian Ocean 5 1 3 Opening of South Atlantic Ocean 5 1 4 Early Andean orogeny 5 2 Cenozoic 5 2 1 Australia Antarctica separation 6 Biogeography 6 1 Post Cambrian diversification 6 2 Modern diversification 7 See also 8 References 8 1 Notes 8 2 Sources 9 External linksName edit nbsp Distribution of four Permian and Triassic fossil groups used as biogeographic evidence for continental drift and land bridgingThe 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 6 The name had been previously used in a geological context first by H B Medlicott in 1872 7 from which the Gondwana sedimentary sequences Permian Triassic are also described Some scientists prefer the term Gondwanaland to make a clear distinction between the region and the supercontinent 8 Formation edit nbsp Eastern Gondwana 620 to 550 Ma post collisional extension of the East African Orogeny in blue and 570 to 530 Ma collisional metamorphism of the Kuunga orogeny in red 9 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 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 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 10 The last stages of Gondwanan assembly overlapped with the opening of the Iapetus Ocean between Laurentia and western Gondwana 11 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 12 The Mozambique Ocean separated the Congo Tanzania Bangweulu Block of central Africa from Neoproterozoic India India the Antongil Block in far eastern Madagascar the Seychelles and the Napier and Rayner Complexes in East Antarctica The Azania continent 13 much of central Madagascar the Horn of Africa and parts of Yemen and Arabia was an island in the Mozambique Ocean nbsp Reconstruction showing final stages of assembly of Gondwana 550 MyaThe 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 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 14 As the rest of Gondwana formed 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 the remaining Gondwana c 570 to 530 Ma in the Kuunga Orogeny 15 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 16 The 18 000 km long 11 000 mi Terra Australis Orogen developed along Gondwana s western southern and eastern margins 17 Proto Gondwanan Cambrian arc belts from this margin have been found in eastern Australia Tasmania New Zealand and Antarctica Though these belts formed a continuous arc chain the direction of subduction was different between the Australian Tasmanian and New Zealand Antarctica arc segments 18 Peri Gondwana development Paleozoic rifts and accretions editMany 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 the continent Kazakhstania in the Late Silurian Whether these blocks originated on the shores of Gondwana is not known 19 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 the Variscan orogeny close to the Carboniferous Permian boundary 20 nbsp nbsp nbsp nbsp Journey of the Asian blocks from Gondwana to Laurasia Late Ordovician to Early Jurassic 450 350 300 and 200 Mya View centred on 0 S 105 E 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 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 the Early Cretaceous and West Burma and Woyla during the Late Cretaceous 21 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 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 22 Southwestern accretions edit During 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 23 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 the Ordovician 24 This is the Cuyania or Precordillera terrane of the Famatinian orogeny in northwest Argentina which may have continued the line of the Appalachians southwards 25 Chilenia terrane accreted later against Cuyania 26 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 the subduction process initiated in the early Carboniferous 27 This was relatively short lived lasting about 20 million years and initial contact of the two landmasses occurred in the mid Carboniferous 27 28 with broader collision during the early Permian 28 In the Devonian an island arc named Chaitenia accreted to Patagonia in what is now south central Chile 29 Gondwana as part of Pangaea Late Paleozoic to Early Mesozoic editMain article Pangaea nbsp Gondwana formed part of Pangaea for c 150 Ma 30 Gondwana and Laurasia formed the Pangaea supercontinent during the Carboniferous Pangaea began to break up in the Mid Jurassic when the Central Atlantic opened 31 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 the other hand remained largely unaffected by the collision along the southern shores of Laurentia Some Peri Gondwanan terranes such as Yucatan 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 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 32 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 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 33 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 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 34 The break up 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 a few million years reached its peak at c 200 Ma and coincided with the Triassic Jurassic extinction event 35 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 the Central Atlantic opened 36 Break up editMesozoic edit 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 is now the southern Weddell Sea where initial break up occurred during the Jurassic c 180 to 160 Ma 37 Opening of western Indian Ocean edit nbsp nbsp The first ocean floor formed between Madagascar and Africa c 150 Ma left and between India and Madagascar c 70 Ma right 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 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 38 The history of the Africa Antarctica break up can be studied in great detail in the fracture zones and magnetic anomalies flanking the Southwest Indian Ridge 39 The Madagascar block and the Mascarene Plateau stretching from the Seychelles to Reunion 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 the eruption of the Deccan basalts whose eruption site may survive as the Reunion 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 40 41 Opening of eastern Indian Ocean edit nbsp nbsp nbsp The first ocean floor formed between India and Antarctica c 120 Ma left The Kerguelen LIP began to form the Ninety East ridge c 80 Ma centre The Indian and Australian plates merged c 40 Ma right 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 42 The Indian Plate and the Australian Plate are now separated by the Capricorn Plate and its diffuse boundaries 43 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 44 The Kerguelen Plateau and the Broken Ridge the southern end of the Ninety East Ridge are now separated by 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 45 A dramatic shift from arc to rift magmatism c 100 Ma separated Zealandia including New Zealand the Campbell Plateau Chatham Rise Lord Howe Rise Norfolk Ridge and New Caledonia from West Antarctica c 84 Ma 46 Opening of South Atlantic Ocean edit nbsp nbsp At c 126 Ma left the Falkland Plateau began to slide past southern Africa and the Parana Etendeka LIP had opened the Mid Atlantic Ridge At c 83 Ma right the South Atlantic was fully opened and the Romanche Fracture Zone was forming near the Equator The opening of the South Atlantic Ocean divided West Gondwana South America and Africa but there is a 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 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 Parana and Etendeka magmatics resulted in further ocean floor spreading c 130 to 135 Ma and 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 47 Early Andean orogeny edit 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 48 49 This development is presumed to have been linked to the subduction of cold oceanic lithosphere 49 During the mid to Late Cretaceous c 90 million years ago the Andean orogeny changed significantly in character 48 49 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 the uplift and erosion known to have occurred from the Late Cretaceous onward 49 Plate tectonic reorganisation since the mid Cretaceous might also have been linked to the opening of the South Atlantic Ocean 48 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 a north east motion at about 90 million years ago 50 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 Liquine Ofqui 49 50 Cenozoic edit 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 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 51 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 52 as well as allowing 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 53 Australia Antarctica separation edit 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 the two developed but remained an embayment until the Eocene Oligocene boundary when the Circumpolar Current developed and the glaciation of Antarctica began 54 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 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 the present arid regime Australia has thus experienced various climate changes over a 15 million year period with a gradual decrease in precipitation 55 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 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 56 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 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 the Antarctic Peninsula increased the renewed ACC resulted in cooler global climate 57 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 58 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 the continent became the arid or semiarid landscape it is today 59 Biogeography editSee also Evolutionary history of plants nbsp Banksia a grevilleoid Proteaceae is an example of a plant from a family with a Gondwanan distributionThe 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 8 For example the plant family Proteaceae known from all continents in 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 60 Post Cambrian diversification edit 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 was followed by a Silurian Hot House period 61 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 62 nbsp nbsp Reconstructions of left a Late Silurian Cooksonia the first land plant and right a Late Devonian Archaeopteris the first large tree By the end of the Ordovician Cooksonia a slender ground covering plant became the first vascular plant to establish itself on land This first colonisation occurred exclusively around 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 the Equator during this period and remained a lifeless and barren landscape 63 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 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 the first trees and by the Late Devonian this first forest was accompanied by the progymnosperms including the first large trees Archaeopteris 64 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 a single jaw from Australia 65 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 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 the first amniote reptilians evolved all closely related to the Laurasian fauna but spreading ice eventually drove these animals away from Gondwana entirely 66 nbsp nbsp Fossilised Walchia and Utrechtia two voltzialean pines from which modern conifers evolved nbsp nbsp nbsp nbsp Still extant Triassic conifers Agathis Wollemia Araucaria and Podocarpus that once dominated Gondwana 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 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 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 67 Modern diversification edit During the Mid to Late Triassic hot house conditions coincided with 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 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 a gradual decline during the Triassic while ferns though never dominant managed to diversify 68 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 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 a pattern that reflects the Jurassic break up of Pangaea 69 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 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 the lake deposits of the Santana Formation in Brazil the Koonwarra Lake fauna in Australia and the Orapa diamond mine in Botswana 70 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 was hardly affected 70 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 71 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 72 nbsp The plant genus Nothofagus provides a good example of a taxon with a Gondwanan distribution having originated in the supercontinent and existing in present day Australia New Zealand New Caledonia and South America s Southern Cone Fossils have also been found in Antarctica 73 The laurel forests of Australia New Caledonia and New Zealand have 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 the Southern Hemisphere continents later See also editContinental drift the movement of the Earth s continents relative to each other Australasian realm Gondwana Rainforests of Australia The Great Escarpment of Southern Africa Plate tectonics a theory which describes the large scale motions of Earth s lithosphere South Polar dinosaurs which proliferated during the Early Cretaceous 145 100 Mya while Australia was still linked to Antarctica to form East Gondwana Gondwana Research a scholarly journal including Gondwana among its emphasesReferences editNotes edit Gondwana Dictionary com Lexico Publishing Group Retrieved 18 January 2010 Meert amp Van der Voo 1997 Abstract Torsvik amp Cocks 2013 Abstract Bradley D C 2011 Secular Trends in the Geologic Record and the Supercontinent Cycle Earth Science Reviews 108 1 2 16 33 Bibcode 2011ESRv 108 16B CiteSeerX 10 1 1 715 6618 doi 10 1016 j earscirev 2011 05 003 S2CID 140601854 Gondwanaland Merriam Webster Online Dictionary Retrieved 18 January 2010 Chakrabarti Pratik 2019 Gondwana and the Politics of Deep Past Past amp Present 242 1 119 153 doi 10 1093 pastj gty016 Suess 1885 p 768 Wir nennen es Gondwana Land nach der gemeinsamen alten Gondwana Flora We name it Gondwana Land after the common ancient flora of Gondwana a b McLoughlin 2001 Gondwana or Gondwanaland pp 272 273 Meert 2003 Fig 10 p 19 Meert amp Van der Voo 1997 Introduction pp 223 226 Miashita amp Yamamoto 1996 Meert amp Van der Voo 1997 p 229 Defined but not named in Collins amp Pisarevsky 2005 Azania was a Greek name for the East African coast Li et al 2008 The birth of Gondwanaland 600 530 Ma p 201 Meert 2003 Abstract Grantham Maboko amp Eglington 2003 Cawood 2005 Definition and Tectonic Framework pp 4 6 Munker amp Crawford 2000 Abstract Torsvik amp Cocks 2013 Marginal microcontinents and terranes p 1008 Torsvik amp Cocks 2013 Southern Europe pp 1008 1009 McLoughlin 2001 Cimmerian terranes p 278 Torsvik amp Cocks 2013 South central and eastern Asia Cawood 2005 Peri Gondwanan continental basement assemblages pp 15 16 Rapalini 2001 Rapalini 1998 pp 105 106 Dalla Salda et al 1998 Abstract Vujovich van Staal amp Davis 2004 Conclusions p 1053 Ramos V A Jordan T E Allmendinger R W Mpodozis C Kay S M Cortes J M Palma M October 1986 Paleozoic terranes of the central Argentina Chilean Andes Tectonics 5 6 855 880 Bibcode 1986Tecto 5 855R doi 10 1029 TC005i006p00855 a b Pankhurst R J Rapela C W Fanning C M Marquez M 1 June 2006 Gondwanide continental collision and the origin of Patagonia PDF Earth Science Reviews 76 3 4 235 257 Bibcode 2006ESRv 76 235P doi 10 1016 j earscirev 2006 02 001 a b Ramos Victor A 1 November 2008 Patagonia A paleozoic continent adrift Journal of South American Earth Sciences 26 3 235 251 Bibcode 2008JSAES 26 235R doi 10 1016 j jsames 2008 06 002 hdl 11336 92748 Herve Francisco Calderon Mauricio Fanning Mark Pankhurst Robert Rapela Carlos W Quezada Paulo 2018 The country rocks of Devonian magmatism in the North Patagonian Massif and Chaitenia Andean Geology 45 3 301 317 doi 10 5027 andgeoV45n3 3117 hdl 11336 81577 Li et al 2008 Abstract Torsvik amp Van der Voo 2002 Data selection and reconstruction fits p 772 Blakey 2003 Assembly of Western Pangaea Carboniferous Permian pp 453 454 Blakey 2003 Assembly of Eastern Pangaea Late Permian Jurassic p 454 Blakey 2003 Summary significance of Pangaean events pp 454 455 Marzoli et al 1999 Abstract Gondwana Remnants in Alabama And Georgia Uchee Is An Exotic Peri Gondwanan Arc Terrane Not Part of Laurentia ScienceDaily 4 February 2008 Retrieved 22 October 2011 Jokat et al 2003 Introduction pp 1 2 Encarnacion et al 1996 Early rifting and Gondwana breakup pp 537 538 Royer et al 1988 Figg 7 a j pp 248 257 Abbate Ernesto Bruni Piero Sagri Mario 2015 Geology of Ethiopia A Review and Geomorphological Perspectives In Billi Paolo ed Landscapes and Landforms of Ethiopia World Geomorphological Landscapes pp 33 64 doi 10 1007 978 94 017 8026 1 2 ISBN 978 94 017 8026 1 Coltorti M Dramis F Ollier C D 2007 Planation surfaces in Northern Ethiopia Geomorphology 89 3 4 287 296 Bibcode 2007Geomo 89 287C doi 10 1016 j geomorph 2006 12 007 Powell Roots amp Veevers 1988 Abstract DeMets Gordon amp Royer 2005 Introduction Fig 1 p 446 Muller Royer amp Lawver 1993 Model results pp 277 278 McLoughlin 2001 East Antarctica Australia p 280 McLoughlin 2001 West Antarctica Tasmania p 280 Seton et al 2012 South Atlantic pp 217 218 a b c Ramos 2009 Abstract a b c d e Charrier Pinto amp Rodriguez 2006 pp 45 46 a b Hoffmann Rothe et al 2006 Yin amp Harrison 2000 Abstract Luyendyk Forsyth amp Phillips 1972 Abstract Jestin Huchon amp Gaulier 1994 Abstract Martin 2006 Palaeogeography pp 538 539 Martin 2006 Conclusions pp 557 558 Lagabrielle et al 2009 Timing of opening of the Drake Passage region pp 198 199 Lagabrielle et al 2009 Conclusions p 210 Hill amp Hall 2003 Abstract Travouillon et al 2009 Abstract Barker et al 2007 Abstract Anderson et al 1999 SILURIAN terrestrial life appears in the tropics p 148 Anderson et al 1999 The First Extinction p 151 Anderson et al 1999 The Silurian revolution p 151 Anderson et al 1999 DEVONIAN colonising Gondwana The Second Extinction Global colonisation of plants pp 151 153 Anderson et al 1999 Amphibian prelude p 153 Anderson et al 1999 CARBONIFEROUS competing with ice pp 153 154 Anderson et al 1999 PERMIAN the glossopterid empire pp 153 154 Anderson et al 1999 TRIASSIC the gymnosperm heyday pp 155 156 Anderson et al 1999 JURASSIC volcanism conifers and bennettitaleans pp 156 158 a b Anderson et al 1999 Cretaceous of flowers and pollination pp 158 159 Gurovich amp Beck 2009 Introduction pp 25 26 Woodburne Rich amp Springer 2003 Gondwana and early mammal evolution p 375 HaoMin amp ZheKun 2007 Sources edit Anderson J M Anderson H M Archangelsky S Bamford M Chandra S Dettmann M Hill R McLoughlin S Rosler O 1999 Patterns of Gondwana plant colonisation and diversification Journal of African Earth Sciences 28 1 145 167 Bibcode 1999JAfES 28 145A doi 10 1016 S0899 5362 98 00083 9 Retrieved 25 November 2017 Barker N P Weston P H Rutschmann F Sauquet H 2007 Molecular dating of the Gondwanan plant family Proteaceae is only partially congruent with the timing of the break up of Gondwana Journal of Biogeography 34 12 2012 2027 doi 10 1111 j 1365 2699 2007 01749 x S2CID 86156197 Retrieved 3 September 2017 Blakey R C 2003 Carboniferous Permian paleogeography of the assembly of Pangaea In Wong Th E ed Proceedings of the XVth International Congress on Carboniferous and Permian Stratigraphy Utrecht Vol 10 p 16 Utrecht the Netherlands Royal Netherlands Academy of Arts and Sciences Cawood Peter A 2005 Terra Australis Orogen Rodinia breakup and development of the Pacific and Iapetus margins of Gondwana during the Neoproterozoic and Paleozoic Earth Science Reviews 69 3 249 279 Bibcode 2005ESRv 69 249C doi 10 1016 j earscirev 2004 09 001 Charrier Reynaldo Pinto Luisa Rodriguez Maria Pia 2006 3 Tectonostratigraphic evolution of the Andean Orogen in Chile In Moreno Teresa Gibbons Wes eds Geology of Chile Geological Society of London pp 21 114 ISBN 9781862392199 Collins A S Pisarevsky S A 2005 Amalgamating eastern Gondwana The evolution of the Circum Indian Orogens Earth Science Reviews 71 3 4 229 270 Bibcode 2005ESRv 71 229C CiteSeerX 10 1 1 558 5911 doi 10 1016 j earscirev 2005 02 004 Dalla Salda L H de Luchi M G L Cingolani C A Varela R 1998 Laurentia Gondwana collision the origin of the Famatinian Appalachian orogenic belt a review Geological Society London Special Publications 142 1 219 234 Bibcode 1998GSLSP 142 219D doi 10 1144 GSL SP 1998 142 01 11 S2CID 140562320 Retrieved 10 September 2017 DeMets C Gordon R G Royer J Y 2005 Motion between the Indian Capricorn and Somalian plates since 20 Ma implications for the timing and magnitude of distributed lithospheric deformation in the equatorial Indian ocean Geophysical Journal International 161 2 445 468 Bibcode 2005GeoJI 161 445D doi 10 1111 j 1365 246X 2005 02598 x Encarnacion J Fleming T H Elliot D H Eales H V 1996 Synchronous emplacement of Ferrar and Karoo dolerites and the early breakup of Gondwana Geology 24 6 535 538 Bibcode 1996Geo 24 535E doi 10 1130 0091 7613 1996 024 lt 0535 seofak gt 2 3 co 2 ISSN 0091 7613 Grantham G H Maboko M Eglington B M 2003 A review of the evolution of the Mozambique Belt and implications for the amalgamation and dispersal of Rodinia and Gondwana Geological Society London Special Publications 206 1 401 425 Bibcode 2003GSLSP 206 401G doi 10 1144 GSL SP 2003 206 01 19 S2CID 128411554 Retrieved 3 September 2017 Gurovich Y Beck R 2009 The phylogenetic affinities of the enigmatic mammalian clade Gondwanatheria Journal of Mammalian Evolution 16 1 25 49 doi 10 1007 s10914 008 9097 3 S2CID 42799370 Retrieved 11 February 2018 HaoMin Li ZheKun Zhou 1 September 2007 Fossil Nothofagaceous Leaves from the Eocene of Western Antarctica and their Bearing on the Origin Dispersal and Systematics of Nothofagus PDF Science in China Series D Earth Sciences 50 10 1525 1535 Bibcode 2007ScChD 50 1525H doi 10 1007 s11430 007 0102 0 S2CID 130395392 Retrieved 10 September 2017 Hill K C Hall R 2003 Mesozoic Cenozoic evolution of Australia s New Guinea margin in a west Pacific context PDF In Hillis R R Muller R D eds Evolution and Dynamics of the Australian Plate Geological Society of America pp 265 290 ISBN 9780813723723 Retrieved 27 January 2018 Hoffmann Rothe Arne Kukowski Nina Dresen Georg Echtler Helmut Oncken Onno Klotz Jurgen Scheuber Ekkehard Kellner Antje 2006 Oblique Convergence along the Chilean Margin Partitioning Margin Parallel Faulting and Force Interaction at the Plate Interface In Oncken Onno Chong Guillermo Franz Gerhard Giese Peter Gotze Hans Jurgen Ramos Victor A Strecker Manfred R Wigger Peter eds The Andes Active Subduction Orogeny Frontiers in Earth Sciences Berlin Heidelberg Springer pp 125 146 doi 10 1007 978 3 540 48684 8 6 ISBN 978 3 540 24329 8 Retrieved 27 January 2018 Jestin F Huchon P Gaulier J M 1994 The Somalia plate and the East African Rift System present day kinematics Geophysical Journal International 116 3 637 654 Bibcode 1994GeoJI 116 637J CiteSeerX 10 1 1 876 4499 doi 10 1111 j 1365 246X 1994 tb03286 x Jokat W Boebel T Konig M Meyer U 2003 Timing and geometry of early Gondwana breakup Journal of Geophysical Research Solid Earth 108 B9 2428 Bibcode 2003JGRB 108 2428J doi 10 1029 2002JB001802 Retrieved 1 October 2017 Lagabrielle Y Godderis Y Donnadieu Y Malavieille J Suarez M 2009 The tectonic history of Drake Passage and its possible impacts on global climate PDF Earth and Planetary Science Letters 279 3 197 211 Bibcode 2009E amp PSL 279 197L doi 10 1016 j epsl 2008 12 037 Li Z X Bogdanova S V Collins A S Davidson A De Waele B Ernst R E Fitzsimons I C W Fuck R A Gladkochub D P Jacobs J Karlstrom K E Lu S Natapov L M Pease V Pisarevsky S A Thrane K Vernikovsky V 2008 Assembly configuration and break up history of Rodinia a synthesis PDF Precambrian Research 160 1 179 210 Bibcode 2008PreR 160 179L doi 10 1016 j precamres 2007 04 021 Retrieved 30 September 2017 Luyendyk B P Forsyth D Phillips J D 1972 Experimental Approach to the Paleocirculation of the Oceanic Surface Waters PDF Geological Society of America Bulletin 83 9 2649 Bibcode 1972GSAB 83 2649L doi 10 1130 0016 7606 1972 83 2649 eattpo 2 0 co 2 Retrieved 1 September 2017 Martin H A 2006 Cenozoic climatic change and the development of the arid vegetation in Australia PDF Journal of Arid Environments 66 3 533 563 Bibcode 2006JArEn 66 533M doi 10 1016 j jaridenv 2006 01 009 Retrieved 26 November 2017 Marzoli A Renne P R Piccirillo E M Ernesto M Bellieni G De Min A 1999 Extensive 200 million year old continental flood basalts of the Central Atlantic Magmatic Province Science 284 5414 616 618 Bibcode 1999Sci 284 616M doi 10 1126 science 284 5414 616 PMID 10213679 Retrieved 1 October 2017 McLoughlin S 2001 The breakup history of Gondwana and its impact on pre Cenozoic floristic provincialism Australian Journal of Botany 49 3 271 300 doi 10 1071 BT00023 Retrieved 3 September 2017 Meert J G 2003 A synopsis of events related to the assembly of eastern Gondwana Tectonophysics 362 1 1 40 Bibcode 2003Tectp 362 1M doi 10 1016 S0040 1951 02 00629 7 Meert J G Van der Voo R 1997 The assembly of Gondwana 800 550 Ma Journal of Geodynamics 23 3 4 223 235 Bibcode 1997JGeo 23 223M doi 10 1016 S0264 3707 96 00046 4 Retrieved 3 September 2017 Miashita Y Yamamoto T 1996 Gondwanaland Its Formation Evolution and Dispersion Journal of African Earth Sciences 23 2 XIX Bibcode 1996JAfES 23D 19M doi 10 1016 s0899 5362 97 86882 0 Muller R D Royer J Y Lawver L A 1993 Revised plate motions relative to the hotspots from combined Atlantic and Indian Ocean hotspot tracks Geology 21 3 275 278 Bibcode 1993Geo 21 275D doi 10 1130 0091 7613 1993 021 lt 0275 RPMRTT gt 2 3 CO 2 Retrieved 1 September 2017 Munker C Crawford A J 2000 Cambrian arc evolution along the SE Gondwana active margin a synthesis from Tasmania New Zealand Australia Antarctica correlations Tectonics 19 3 415 432 Bibcode 2000Tecto 19 415M doi 10 1029 2000TC900002 S2CID 129154382 Powell C Roots S R Veevers J J 1988 Pre Breakup Continental Extension in East Gondwanaland and the Early Opening of the Eastern Indian Ocean Tectonophysics 155 1 4 261 283 Bibcode 1988Tectp 155 261P doi 10 1016 0040 1951 88 90269 7 Ramos V A 2009 Anatomy and global context of the Andes Main geologic features and the Andean orogenic cycle Geological Society of America Memoirs 204 31 65 doi 10 1130 2009 1204 02 ISBN 9780813712048 Retrieved 15 December 2015 Rapalini A E 2001 The Assembly of Southern South America in the Late Proterozoic and Paleozoic Some Paleomagnetic Clues Spring Meeting 2001 American Geophysical Union Bibcode 2001AGUSM GP32D03R Rapalini A E 1998 Syntectonic magnetization of the mid Palaeozoic Sierra Grande Formation further constraints on the tectonic evolution of Patagonia PDF Journal of the Geological Society 155 1 105 114 Bibcode 1998JGSoc 155 105R doi 10 1144 gsjgs 155 1 0105 S2CID 140198760 Retrieved 10 September 2017 Royer J Y Patriat P Bergh H W Scotese C R 1988 Evolution of the Southwest Indian Ridge from the Late Cretaceous anomaly 34 to the Middle Eocene anomaly 20 Tectonophysics 155 1 4 235 260 Bibcode 1988Tectp 155 235R doi 10 1016 0040 1951 88 90268 5 S2CID 128563461 Retrieved 31 July 2016 Seton M Muller R D Zahirovic S Gaina C Torsvik T Shephard G Talsma A Gurnis M Maus S Chandler M 2012 Global continental and ocean basin reconstructions since 200Ma Earth Science Reviews 113 3 212 270 Bibcode 2012ESRv 113 212S doi 10 1016 j earscirev 2012 03 002 Retrieved 23 October 2016 Suess E 1885 Das Antlitz der Erde The Face of the Earth in German Vol 1 Leipzig Germany G Freytag Retrieved 3 September 2017 Torsvik T H Cocks L R M 2013 Gondwana from top to base in space and time PDF Gondwana Research 24 3 999 1030 Bibcode 2013GondR 24 999T doi 10 1016 j gr 2013 06 012 Retrieved 18 September 2013 Torsvik T H Van der Voo R 2002 Refining Gondwana and Pangea Palaeogeography Estimates of Phanerozoic non dipole octupole fields PDF Geophysical Journal International 151 3 771 794 Bibcode 2002GeoJI 151 771T doi 10 1046 j 1365 246X 2002 01799 x Retrieved 16 September 2017 Travouillon K J Legendre S Archer M Hand S J 2009 Palaeoecological analyses of Riversleigh s Oligo Miocene sites implications for Oligo Miocene climate change in Australia Palaeogeography Palaeoclimatology Palaeoecology 276 1 4 24 37 Bibcode 2009PPP 276 24T doi 10 1016 j palaeo 2009 02 025 Vujovich G I van Staal C R Davis W 2004 Age constraints on the tectonic evolution and provenance of the Pie de Palo Complex Cuyania composite terrane and the Famatinian Orogeny in the Sierra de Pie de Palo San Juan Argentina PDF Gondwana Research 7 4 1041 1056 Bibcode 2004GondR 7 1041V doi 10 1016 S1342 937X 05 71083 2 Retrieved 10 September 2017 Woodburne M O Rich T H Springer M S 2003 The evolution of tribospheny and the antiquity of mammalian clades Molecular Phylogenetics and Evolution 28 2 360 385 doi 10 1016 S1055 7903 03 00113 1 PMID 12878472 Yin A Harrison T M 2000 Geologic evolution of the Himalayan Tibetan orogen PDF Annual Review of Earth and Planetary Sciences 28 1 211 280 Bibcode 2000AREPS 28 211Y doi 10 1146 annurev earth 28 1 211 Retrieved 26 November 2017 External links editHouseman Greg Animation of the dispersal of Gondwanaland University of Leeds Retrieved 21 October 2008 Barend Kobben Colin Reeves Maarten de Wit Interactive animation of the breakup of Gondwana ITC University of Twente Retrieved 16 October 2017 Graphical subjects dealing with Tectonics and Paleontology Gondwana Reconstruction and Dispersion The Gondwana Map Project Archived 20 September 2019 at the Wayback Machine van Hinsbergen Douwe J J Torsvik Trond H Schmid Stefan M Maţenco Liviu C Maffione Marco Vissers Reinoud L M Gurer Derya Spakman Wim September 2019 Orogenic architecture of the Mediterranean region and kinematic reconstruction of its tectonic evolution since the Triassic Gondwana Research 81 79 229 Bibcode 2020GondR 81 79V doi 10 1016 j gr 2019 07 009 hdl 20 500 11850 390104 Retrieved from https en wikipedia org w index php title Gondwana amp oldid 1196791553, wikipedia, wiki, book, books, library,

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