500 million years ago, in the Ordovician period, southern Britain, the east coast of North America and south-east Newfoundland broke away from Gondwana to form the continent of Avalonia, which by 440 Ma had drifted ( by the mechanisms of plate tectonics ) to about 30 ° south.

In the early Cambrian, the supercontinent Pannotia broke up and Avalonia drifted off northwards from Gondwana.

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.

For example, the Caledonian Orogeny refers to the Silurian and Devonian events that resulted from the collision of Laurentia with Eastern Avalonia and other former fragments of Gondwana.

These deposits are closely associated with the erosion of the Caledonian Mountain chain which was thrown up by the collision of the former continents of Avalonia, Baltica and Laurentia to form the Old Red Sandstone Continent-an event known as the Caledonian Orogeny.

Avalonia had now joined with the continent of Baltica, and the combined landmass collided with Laurentia at about 20 ° south between 425 and 400 Ma, joining the southern and northern halves of Great Britain together.

Some authors consider the oceanic basin south of the island arc also a part of the Iapetus, this branch closed during the later Acadian orogeny, when Avalonia collided with Laurentia.

The final collision occurred during the Devonian period, with the Scottish segment of the Laurentian plate smashing into Avalonia ( which contained what is now most of England and Wales ), a motile subcontinent which had previously joined with Baltica.

Euramerica ( also known as Laurussia ( not to be confused with Laurasia ), the Old Red Continent or the Old Red Sandstone Continent ) was a minor supercontinent created in the Devonian as the result of a collision between the Laurentian, Baltica, and Avalonia cratons ( Caledonian orogeny ).

* ~ late Ordovician, Baltica collided with Avalonia ( most of modern Western Europe )

The eastern end of Avalonia collided with Baltica, a continental plate occupying the latitudes from about 30 ° S to 55 ° S, as Baltica slowly rotated anticlockwise towards it.

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 the USA and Canada.

This was happening at around the Equator during the later Carboniferous, forming Pangaea with Avalonia near its centre but partially flooded by shallow sea.

In the Jurassic, Pangaea split into Laurasia and Gondwana, with Avalonia as part of Laurasia.

In the Cretaceous, Laurasia broke up into North America and Eurasia with Avalonia split between them.

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.

Euramerica in the Devonian ( 416 to 359 Ma ) with Baltica, Avalonia ( Cabot Fault, Newfoundland ( island ) | Newfoundland and Great Glen Fault, Scotland ) and Laurentia.

During the early Triassic, the super-continent Pangea was formed as the Iapetus Ocean closed up and the proto-North American continent collided with Avalonia, part of modern-day Africa.

The Laurentian craton became a part of North America while Baltica became a part of Eurasia, and Avalonia was split between the two.

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 North Sea is located at an old triple junction of three former continental plates of the Palaeozoic era: Avalonia, Laurentia and Baltica.

The Avalonia land mass originally included parts of Great Britain and southern Europe but was rifted away from North America during the Triassic opening of the Atlantic Ocean.

Avalonia was gradually torn apart as plate tectonic forces accreted the landmass onto the edge of the larger North American continent.

Today, portions of the ancient Avalonia landmass occur in scattered outcrop belts along the eastern margin of North America.

In North America, the collision between Avalonia and Laurentia is called the Acadian orogeny.

Thus Avalonia formed the southern coast of the new continent Euramerica ( Laurussia, the Old Red Sandstone continent in present day North America, British Isles, northern Germany, Scandinavia and western Russia ).

In late Devonian and in the Carboniferous the archipelago Armorica of southern Europe, which had rifted off Gondwana after Avalonia later in the Ordovician, was pushed into Avalonia, creating a second range, the North American / European Variscan, to the east of the Caledonide / Appalachian.

The ocean was bounded to the south by the large paleocontinent Gondwana ( containing the crust of future Africa, South America, southern Eurasia, Australia and Antarctica ), later by terranes that broke off Gondwana, like the microcontinent Avalonia ( at present lithosphere that is scattered over the east of New England, the south of Newfoundland, parts of New Brunswick and Nova Scotia, southern Ireland, most of England and Wales, the low countries and northern Germany ).

This independent movement of Avalonia started from a latitude of about 60 ° South.

In the Early Ordovician epoch ( about 480 million years ago ) the microcontinent ( a small fragment of continental lithosphere ) Avalonia ( at present lithosphere that is scattered over the east of New England, the south of Newfoundland, parts of New Brunswick and Nova Scotia, southern Ireland, most of England and Wales, the low countries and northern Germany ) began to separate from the northern margin of Gondwana.

In the Late Ordovician ( about 450 million years ago ) continental collision started between Avalonia and Baltica.

All of Rhode Island was part of a volcanic arc or micro-continent called Avalonia, which formed south of the equator more than 565 million years ago.

The same happened further north and east, where Avalonia and Baltica began to move towards Laurentia from the Ordovician ( 488-444 million years ago ) onward.

Meanwhile, the eastern parts had closed too: the Tornquist Sea between Avalonia and Baltica already during the late Ordovician, the main branch between Baltica-Avalonia and Laurentia during the Grampian and Scandian phases of the Caledonian orogeny ( 440-420 million years ago ).

Position of the continents Baltica, Laurentia and Avalonia around 460 million years ago.

The state is underlain by the Avalon terrane and was once part of the micro-continent Avalonia prior to closure of the Iapetus ocean.

At a depth of 5 m ( 16 feet ) the monks discovered a massive treetrunk coffin and a leaden cross bearing the inscription: Hic jacet sepultus inclitus rex Arthurus in insula Avalonia.

During the Ordovician period the collision of Laurentia, Gondwanaland, and Avalonia, referred to as the Taconic Orogeny, caused the formation to fold, thrust, and uplift above sea level, where later layers were eroded away and the schist was exposed.

The peninsula gives its name to the ancient micro-continent Avalonia of which it was part.

The Iapetus Ocean was situated in the southern hemisphere, between the paleocontinents of Laurentia, Baltica and Avalonia.

*; 2003: The Tornquist Sea and Baltica – Avalonia docking, Tectonophysics 362, pp. 67 – 82.

Avalonia was a microcontinent in the Paleozoic era.

Avalonia is named for the Avalon Peninsula in Newfoundland.

Avalonia developed as a volcanic arc on the northern margin of Gondwana.

Schematic diagram of the paleogeographic evolution of Avalonia, Baltica and Laurentia.

The early development of Avalonia is believed to have been in volcanic arcs near a subduction zone on the margin of Gondwana.