Geological history and supercontinent cycles of the Arctic

The geological history of the Arctic is con-strained within the framework of the assem-bly and breakup of three supercontinents. The first of these was preceded by the crys-tallization of the oldest dated rocks on Earth and consolidation of the Arctic region's Ar-chean cratons between 2.82 and 2.54 Ga. Following the emplacement of regional mafic dike swarms between 2.51 and 2.03 Ga, the cratons were amalgamated into the Nuna (Columbia) supercontinent between 2.0 and 1.6 Ga, and the distribution of low-thermal -gradient eclogite (indicative of continental subduction) and ophiolite (indicative of ob-duction of oceanic crust onto a continental margin) suggests that diagnostic plate -tec-tonic processes were well in place by the early Paleoproterozoic. Basin formation, flood basalts, and dike swarms are features of the partial(?) breakup of Nuna (Columbia) by 1.5-1.27 Ga. The extent to which specific dike swarms led to continental breakup and a rift -to-drift transition remains unclear. Assembly of the second supercontinent (Rodinia, 1.4- 0.9 Ga) is recorded by a network of Grenvil-lian and Sveconorwegian collisional orogenic belts. Prominent features of Rodinia breakup (780-615 Ma) in the Arctic are extensive dike swarms and regional-scale glacial-peri-glacial deposits associated with the Sturtian (717-661 Ma) and Marinoan (ca. 645 +/- 6 to ca. 635 Ma) snowball Earth glaciations. As-sembly of the third supercontinent, Pangea, between 600 Ma and ca. 250 Ma, was ac-complished through stitching of four orogens in the Arctic (Timan-Varanger, Caledonian, Ellesmerian, and Urals-Taymyr). Pangea breakup (rifting since 250 Ma and oceanic spreading since the Cretaceous) led to the em-placement of Cretaceous and Paleogene flood basalts, new oceanic crust in the Labrador Sea, North Atlantic Ocean, and Arctic Ocean, and orogens characterized by relatively small but far-traveled accreted terranes with prov-enance in Laurentia, Baltica, and Siberia. Pa-leogeographic similarities and geological cor-relations among Laurentia, Baltica, Siberia, and the North China craton suggest that Ro-dinia formed following incomplete breakup of Nuna (Columbia) and/or by introversion, whereas unique paleogeographic traits for Pangea within the Arctic region point to su-percontinent formation by extroversion.

Automated summary

The geological history of the Arctic is shaped by the assembly and breakup of three supercontinents, namely Nuna (Columbia), Rodinia, and Pangea. The formation and breakup of these supercontinents have had significant impacts on the geological formations in the Arctic region.