Datensatz

Zusammenfassung

Three supercontinents have been suggested to have existed in the last 1 Gyr. The supercontinent status of Pangea and Rodinia is undisputed. In contrast, there is an ongoing controversy whether Pannotia existed at all. Here we test the hypothesis of a Pannotian supercontinent. Using first order tectonic constraints we reconstruct the Paleozoic kinematics of major continents relative to the East European Craton. Back-rotation from Pangea results in a supercontinent constellation in the early Paleozoic corroborating the existence of Pannotia. The presented model explains first order constraints for both the breakup of Pannotia and the subsequent assembly of Pangea. The breakup of Pannotia comprises (i) the early Paleozoic opening of Iapetus II and in turn the Rheic Ocean concomitant with the subduction of the Neo-Proterozoic Iapetus I Ocean, and (ii) the coeval opening of the Paleo-Arctic Ocean, that separated Siberia from the North American Craton. The subsequent convergence of the North American Craton, Avalonia, Gondwana, and Siberia with the East European Craton resulted in Paleozoic collisional orogenies at different plate boundary zones. The existence of Rodinia, Pannotia, and Pangea as pari passu supercontinents implicates two complete supercontinent cycles from Rodinia to Pannotia and from Pannotia to Pangea in the Neoproterozoic and the Paleozoic, respectively.