Geodynamics of the Arctic: From proterozoic orogens to present day seafloor spreading

Abstract

The Circum-Arctic terrains comprise series of complex geological structures, with fragments of Archaean to Paleoproterozoic shields and platforms, remains of orogenic belts of Neo-proterozoic to Cenozoic ages, Paleozoic and Mesozoic platforms and sedimentary basins, large igneous provinces, and Mesozoic-Cenozoic rift structures and basin fill in the northern North Atlantic and Central Arctic Ocean. Major orogenic events include the Neoproterozoic Timian Orogeny, the Mid Paleozoic Caledonian and Eurekean orogenies, the Late Paleozoic to Early Mesozoic Ellesmerian and Uralian orogenies, and the Late Mesozoic to Cenozoic Eurekan orogeny. The breakup of Arctida-II in the Mesozoic and Cenozoic, and the Cenozoic sea-floor spreading in the North Atlantic and Polar Ocean, led to significant redistribution of land masses and to the formation of the present Arctic Ocean shelves and basins. The central Arctic Ocean remains one of the more debated areas in terms of plate tectonic evolution. Most models include spreading in the Canada Basin (southern Amerasia Basin) at ca. 125–80 Ma, the Makarov-Podvodnikov Basin (northern Amerasia Basin) at around 80–60 Ma, and the Eurasia Basin at ca. 55-0 Ma. Different crustal and tectonic models for the Amerasia and Eurasia basins and their margins are discussed, and present knowledge of the basin fill histories briefly reviewed. The present paper serves as an introduction to the current Special Issue on the Geodynamics of the Arctic.