The rocks of the main block of Avalonia as they relate to modern coasts and boundaries but in their relative positions as they were at the end of the Carboniferous, before Europe and North America separated again. The names are given in their French forms.

Avalonia was an ancient microcontinent or terrane whose history formed much of the older rocks of Western Europe, Atlantic Canada, and parts of the coastal United States. Continental crustal fragments or microcontinents are fragments of continents thought to have been broken off from the main continental mass forming distinct islands possibly A terrane in Geology is a fragment of crustal material formed on or broken off from one Tectonic plate and accreted — " sutured " Western Europe at its most general meaning means 'all the countries in the West of Europe ' The United States of America —commonly referred to as the The name is derived from the Avalon Peninsula in Newfoundland. The Avalon Peninsula is a large Peninsula (10360 km²) that makes up the southeast portion of the island of Newfoundland. Newfoundland — ˈn(jufənˌlænd (Terre-Neuve Talamh an Éisc — is a large island 15 km off the east coast of

Development

The early development of Avalonia is believed to have been in volcanic arcs near a subduction zone on the margin of Gondwana. A volcanic arc is a chain of volcanic islands or Mountains formed by Plate tectonics as an oceanic Tectonic plate subducts under In Geology, a subduction zone is an area on Earth where two tectonic plates meet and move towards one another with one sliding underneath the other Gondwana (ɡɒnˈdwɑːnə originally Gondwanaland) was a southern Supercontinent that existed about 500 to 200 Ma ago ^[1] Some material may have accreted from volcanic island arcs which formed further out in the ocean and later collided with Gondwana as a result of plate tectonic movements. The igneous activity had started by 730 million years ago and continued until around 570 million years ago, in the late Neoproterozoic. The Neoproterozoic Era is the unit of geologic time from 1000 to 542 +/- 0 ^[2]

In the early Cambrian, the supercontinent Pannotia broke up and Avalonia drifted off northwards from Gondwana. The Cambrian is a geologic period and system that began about Ma (million years ago at the end of the Proterozoic eon and ended about Ma with In Geology, a supercontinent is a Landmass comprising more than one Continental core or Craton. Pannotia, first described by Ian W D Dalziel in 1997 is a hypothetical Supercontinent that existed from the Pan-African orogeny about 600 million years ago to the This independent movement of Avalonia started from a latitude of about 60° South. The eastern end of Avalonia collided with Baltica, a continental plate occupying the latitudes from about 30°S to 55°S, as the latter slowly rotated anticlockwise towards it. Baltica redirects here For the Russian beer, see Baltika Breweries Baltica is a name applied by geologists to a late- Proterozoic, This happened at the end of the Ordovician and during the early Silurian. The Ordovician is a geologic period and system, the second of six of the Paleozoic era, and covers the time between 488 The Silurian is a geologic period and system that extends from the end of the Ordovician period about 443

In the late Silurian and lower Devonian, the combined Baltica and Avalonia collided progressively, with Laurentia, beginning with the long extremity of Avalonia which is now attached to America. The Silurian is a geologic period and system that extends from the end of the Ordovician period about 443 The Devonian is a geologic period and system of the Paleozoic era spanning from to  million years ago. Laurentia (also known as the North American craton) like all Craton land was created as continents moved about the surface of the Earth The result of this was the formation of Euramerica. Euramerica (also known as Laurussia or Old Red Continent) was a minor Supercontinent created in the Devonian as the result of a collision between At the completion of this stage, the site of Britain was at 30°S and Nova Scotia at about 45°S. This collision is represented by the Caledonian folding or in North America as an early phase in the Acadian orogeny. The Caledonian orogeny is a mountain building event recorded in the Mountains and Hills of northern Scotland, Ireland, England, The Acadian orogeny is a middle Paleozoic deformation especially in the northern Appalachians, between New York and Newfoundland.

In the Permian, the new continent and another terrane, Armorica which included Iberia, drifted in from Gondwana, trapping Avalonia between it and the continent so adding Iberia/Armorica to Euramerica. The Permian is a geologic period and system that extends from 299 This was followed up by the arrival of Gondwana. The effects of these collisions are seen in Europe as the Variscan folding. The Variscan (or Hercynian) orogeny is a geologic mountain-building event caused by Late Paleozoic Continental collision between Laurasia In North America it shows as later phases of the Acadian orogeny. This was happening at around the Equator during the later Carboniferous, forming Pangaea in such a way that Avalonia was near its centre but partially flooded by shallow sea. The Carboniferous is a geologic period and system that extends from the end of the Devonian period about 359 Pangaea, Pangæa or Pangea (pænˈdʒiːə from παν pan, meaning entire, and Γαῖα Gaea, meaning Earth in

In the Jurassic, Pangaea split into Laurasia and Gondwana, with Avalonia as part of Laurasia. The Jurassic is a geologic period and system that extends from about Ma (million years ago to  Ma that is from the end of the Triassic to the beginning Laurasia (lɔˈreɪʃiə lɔˈreɪʒə was a Supercontinent that most recently existed as a part of the split of the Pangaean supercontinent in the late Mesozoic In the Cretaceous, Laurasia broke up into North America and Eurasia with Avalonia split between them. The Cretaceous (kriːˈteɪʃəs, usually abbreviated 'K' for its German translation "Kreide" is a geologic period and system, reaching from the end of For the superstate in George Orwell 's novel see Nations of Nineteen Eighty-Four.

Iberia was later rotated away again as the African part of Gondwana brushed past. This last movement caused the Alpine orogeny including the raising of the Pyrenees during the Miocene and Pliocene. The Alpine orogeny (sometimes also called Alpide orogeny) is an orogenic phase in the Tertiary that formed the mountain ranges of the Alpide belt The Pyrenees (Pirineos French: Pyrénées; Catalan: Pirineus; Occitan: Pirenèus; Aragonese: Perinés The Miocene is a geological epoch of the Neogene period and extends from about 23 The Pliocene epoch (spelled Pleiocene in some older texts is the period in the Geologic timescale that extends As a result of this, part of Avalonia is now to be found on each side of the Straits of Gibraltar. The Strait of Gibraltar ( Arabic: مضيق جبل طارق Spanish: Estrecho de Gibraltar) is the Strait that connects the Atlantic

This map shows the positions of the rocks of Avalonia remaining in Europe. The notes on it indicate the part which collided with Baltica in the upper Ordovician and that which collided with Laurentia in the Silurian. The parts of Avalonia now in Iberia and Morocco were carried there by rotation of Iberia during the subsequent collision with Gondwana followed by separation. These rocks are by no means all at the modern surface.

Consequences

In the modern world, we see Avalonia as forming the basic structure of the Ardennes of Belgium and north-eastern France, north Germany, north-western Poland, England, Wales, south-eastern Ireland, the south-western edge of the Iberian Peninsula, the Avalon Peninsula, much of Nova Scotia, southern New Brunswick and parts of New England. For the political subdivision of France see Ardennes (department. The Kingdom of Belgium is a Country in northwest Europe. It is a founding member of the European Union and hosts its headquarters as well as those This article is about the country For a topic outline on this subject see List of basic France topics. Germany, officially the Federal Republic of Germany ( ˈbʊndəsʁepuˌbliːk ˈdɔʏtʃlant is a Country in Central Europe. Poland (Polska officially the Republic of Poland England is a Country which is part of the United Kingdom. Its inhabitants account for more than 83% of the total UK population whilst its mainland Ireland (pronounced /ˈaɾlənd/ Éire) is the third largest island in Europe, and the twentieth-largest island in the world Nova Scotia (ˌnəʊvəˈskəʊʃə ( Latin for New Scotland; Alba Nuadh Nouvelle-Écosse is a Canadian province located on Canada 's New Brunswick ( French: Nouveau-Brunswick /nuvobʁɔnzwik/ is one of Canada 's three Maritime provinces and is the only constitutionally History See also History of New England New England's earliest inhabitants were Algonquian -speaking Native Americans including the See map 2, Acadian Orogeny and The Acadian orogeny. The Acadian orogeny is a middle Paleozoic deformation especially in the northern Appalachians, between New York and Newfoundland. The Iapetus Ocean was an Ocean that existed in the Southern Hemisphere between Laurentia ( Scotland and North America) and Baltica

The Avalonian part of Britain almost exactly coincides with England and Wales. Part of this which had formed an island in the Carboniferous, so affecting the disposition of coalfields, is known by names such as the 'London-Brabant Island'. The London-Brabant Island goes under a number of names such as London Island, London Platform, London-Brabant Massif, Wales-Brabant Massif Its bulk had an effect on the geological structure between the Ardennes and the English Midlands by influencing the subsequent crustal folding resulting from the Variscan collision. This article is mainly about the English Midlands For other uses see Midlands (disambiguation.

In Canada, Avalonia comprises the Avalon Peninsula of southeast Newfoundland, portions of New Brunswick, Nova Scotia, Prince Edward Island. Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page The Avalon Peninsula is a large Peninsula (10360 km²) that makes up the southeast portion of the island of Newfoundland. Newfoundland — ˈn(jufənˌlænd (Terre-Neuve Talamh an Éisc — is a large island 15 km off the east coast of New Brunswick ( French: Nouveau-Brunswick /nuvobʁɔnzwik/ is one of Canada 's three Maritime provinces and is the only constitutionally Nova Scotia (ˌnəʊvəˈskəʊʃə ( Latin for New Scotland; Alba Nuadh Nouvelle-Écosse is a Canadian province located on Canada 's Prince Edward Island (ˌprɪns ˌɛdwɚd ˈaɪlɨnd ( PEI or P In the United States, Avalonia comprises northern coastal Maine, other sections of coastal New England, and sections of coastal North Carolina. The United States of America —commonly referred to as the The State of Maine ( is a state in the New England region of the northeastern United States of America, bordering the Atlantic Ocean History See also History of New England New England's earliest inhabitants were Algonquian -speaking Native Americans including the North Carolina ( is a state located on the Atlantic Seaboard in the southeastern United States

Maps

• [1] These maps show the relative positions of the terranes and continental plates at various stages in the Ordovician, Silurian and Devonian respectively. The names shown are in their German forms.

See also

• Iceland - a microcontinent
• Mistaken Point (Newfoundland and Labrador)

References

1. ^ Virtual Explorer
2. ^ Woodcock, N. Iceland, officially the Republic of Iceland ( ( Ísland or Lýðveldið Ísland ( & Strachan, R. , eds, (2000) Geological History of Britain and Ireland, Blackwell, pp 127-139.

External links

• Article about Avalonia at Palaeos.Com (licensed under Attribution-NonCommercial 1. 0 complete with pictures)
• The context of Avalonia's movements (not available without registration)
• Relative positions of Avalonia and Gondwana