Avalonia

Avalonia was a peri-Gondwanan microcontinent that rifted from Gondwana during the Paleozoic and later accreted to Laurentia and Baltica, helping form parts of eastern North America and western Europe.

Gondwana: Gondwana was a southern supercontinent that assembled during the Neoproterozoic and persisted into the Mesozoic. Avalonia rifted from Gondwana’s northern margin during the Paleozoic.
Microcontinent: A microcontinent is a fragment of continental crust separated from a larger continent by rifting or tectonic activity. Avalonia is a classic example of a continental fragment with a distinct tectonic history.
Avalonian orogeny: The Avalonian orogeny was a period of late Neoproterozoic to early Cambrian deformation and mountain building in Avalonia. It records tectonic activity within the microcontinent before its later Paleozoic accretion.
Laurentia: Laurentia was an ancient continental landmass that formed the core of much of present-day North America. It was the western continental partner in Avalonia’s Paleozoic accretion.
Iapetus Ocean: The Iapetus Ocean was an ancient ocean that separated Laurentia from Baltica and Avalonia before their Paleozoic convergence. Avalonia crossed this ocean as it moved toward Laurentia and Baltica.
Terrane: A terrane is a crustal block with a geological history distinct from neighboring blocks, later joined to them by tectonic processes. Avalonia is treated as a composite terrane accreted to larger continental margins.
Newfoundland: Newfoundland is a Canadian island containing extensive rocks formed during the opening and closure of the Iapetus Ocean. Its geology preserves major evidence of Avalonia and its collision with Laurentia.
Baltica: Baltica was an ancient continental landmass comprising much of present-day northern and eastern Europe. It was a separate continental neighbor that later collided with Avalonia.
Rheic Ocean: The Rheic Ocean was a Paleozoic ocean that opened as peri-Gondwanan terranes separated from Gondwana. Its opening accompanied Avalonia’s departure from Gondwana.
Continental rifting: Continental rifting is the stretching and thinning of continental lithosphere that can lead to breakup and ocean-basin formation. Rifting separated Avalonia from Gondwana.

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