Vendian glaciations and their relation to the dispersal of Rodinia: Paleomagnetic constraints

Paleomagnetic data from the interglacial Nyborg Formation (653 ± 7 Ma), northern Norway, compare with data from the Egersund dikes (ca. 650 Ma), southwest Norway, and demonstrate that tillite formations associated with the Varanger Ice Age in Baltica accumulated at latitudes greater than 30° S. Vendian glaciations are associated with reorganization of the Rodinia supercontinent, but they are controlled by latitude. The breakup of Rodinia and opening of the proto-Pacific imposed clockwise rotation and southward movement of Laurentia-Baltica. On their combined approach toward the south pole, Baltica and northeast Laurentia were first glaciated during the Varanger Ice Age (ca. 650 Ma) and then by the Ice Brook glacial events (625 580 Ma) when Laurentia had reached intermediate southern latitudes. During the 625 580 Ma period Laurentia and Baltica drifted apart, resulting in the opening of the Iapetus ocean, but both continents remained in high southern latitudes during most of the Vendian.