SIBERIA-LAURENTIA CONNECTIONS IN RODINIA

There is general agreement that most of Earth’s continental crust was assembled in a supercontinent, Rodinia, which formed during collisional events in the late Mesoproterozoic and early Neoproterozoic. At least seven alternative reconstructions of the Laurentia-Siberia connections in this supercontinent were published in recent years. We analyse all of them using palaeomagnetic, geochronological, and geological data. Some previously proposed Laurentia-Siberia reconstructions may be dismissed, whereas other models are permissible with minor modifications and conservative assumptions about recent geochronological data from Siberia. An analysis of the Riphean sedimentary successions along the margins of the Siberian craton, together with recent geochronological and palaeomagnetic data from Siberia, suggest that most of Siberian margins faced oceans in Rodinia times. A comparison of Laurentian and Siberian apparent polar wander paths between 1050 and 1000 Ma shows a striking similarity. However, if Siberia was part of Rodinia, it was probably not contiguous with the Laurentian craton. In this scenario northern and southern (Stanovoy block) margins of Siberia are possible candidates for conjunction with the rest of Rodinia. We propose a new reconstruction of Laurentia and Siberia at ca. 1050 – 1000 Ma. New geochronological data from the mafic dykes of south Siberia suggest their possible relation with the Franklinian magmatic event in north Laurentia.