Ediacaran-Middle Paleozoic Oceanic Voyage of Avalonia from Baltica via Gondwana to Laurentia: Paleomagnetic, Faunal and Geological Constraints

Current Ediacaran Cambrian, paleo-geographic reconstructions place Avalonia, Carolinia and Ganderia (Greater Avalonia) at high paleolatitudes off northwestern Gondwana (NW Africa and/or Amazonia), and locate NW Gondwana at either high or low paleolatitudes. All of these reconstructions are incompatible 550 Ma Avalonian paleomagnetic data, which indicate a paleolatitude of 20-30 degrees S for Greater Avalonia and oriented with the present-day southeast margin on the northwest side, Ediacaran, Cambrian and Early Ordovician fauna in Avalonia are mainly endemic, which suggests that Greater Avalonia was an island micro continent, Except for the degree of Ediacaran deformation, the Neoproterozoic geological records of mildly deformed Greater Avalonia and the intensely deformed Bolshezemel block in the Timanian orogen into eastern Baltica raise the possibility that the were originally along strike from one another, passing from an island micro continent to an arc continent collision al zone, respectively. Such a location and orientation is consistent with: (i) Ediacaran (580-550 Ma) ridge -trench collision leaching to transform motion along the backarc basin; (ii) the reversed, ocean-to-continent polality of the Ediacaran cratonic island arc recorded in Greater Avalonia; (iii) derivation of 1-2 Ga and 760-590 Ma detrital zircon grains in Greater Avalonia from Baltica and the Bolshezemel block (NE Timanides); and (iv) the similarity of 840-1760 Ma T-DM, model ages from detrital zircon in pre-Uralian Timanian and Nd model ages from Greater Avalonia, During the Cambrian, Greater Avalonia rotated 1500 counterclockwise ending up off northwestern Gondwana by the beginning of the Ordovician, after which it migrated orthogonally across Iapetus to amalgamate with eastern Laurentia by the Late Ordovician-Early Silurian.