BALTICA AND SIBERIA INVERTED: A NEW RODINIA RECONSTRUCTION LINKING THE BREAK UP OF THE IAPETUS OCEAN AND THE ÆGIR SEA TO THE PERI-GONDWANA EVENTS

We propose a reassessment of the classic Wilson Cycle paleoreconstruction depicting an Atlantic-type early Paleozoic (Iapetus) ocean between western Norway and East Greenland, and argue that Baltica was geographically inverted throughout the Neoproterozoic (peri-Urals juxtaposed to East Greenland) and that Siberia was inverted and positioned directly east of Baltica. The new model utilizes the same paleomagnetic data for Baltica but the magnetic polarity for the Neoproterozoic data has been inverted. The new reconstruction thereby dismisses the need for a near-instant post-break up (Vendian) 180o rotation of Baltica before the Timanian collision of inverted Baltica (in Northern Norway, Timan and Pechora) and peri-Gondwana terranes (Avalonia, Florida and Cadomia). Compared to previous models the new reconstruction presents more plausible geologic correlations of basement regions, ophiolites, stratigraphy and detrital zircons in sedimentary basins and tectonic events between Baltica, Laurentia, Gondwana and Siberia and a number of smaller terranes. In our reconstruction, the breakup that led to the formation of the Iapetus Ocean was initiated at a triple-junction between a rift (Laurentia-Gondwana), a right-lateral fault (Laurentia-Baltica), and a trench (Baltica-Gondwana), thereby linking the Late Precambrian Iapetus opening to the Timanian and Avalonian orogenies between Gondwana and an inverted Baltica. We propose that these events are intimately linked to rifting of the Ægir Sea between inverted Baltica and inverted Siberia and the Vendian Mid Baltic failed rift (the Moscov-Mesen Basin).