GEOSCAN, résultats de la recherche


TitreLong-lived connection between southern Siberia and northern Laurentia in the Proterozoic
AuteurErnst, R E; Hamilton, M A; Sderlund, U; Hanes, J A; Gladkochub, D P; Okrugin, A V; Kolotilina, T; Mekhonoshin, A S; Bleeker, W; LeCheminant, A N; Buchan, K L; Chamberlain, K R; Didenko, A N
SourceNature Geoscience vol. 9, 6, 2016 p. 464-469,
Séries alt.Ressources naturelles Canada, Contribution externe 20182266
ÉditeurNature Publishing Group
Documentpublication en série
Mediapapier; en ligne; numérique
ProgrammeContrôle des dépôts dans les zones cratoniques, Initiative géoscientifique ciblée (IGC-5)
Diffusé2016 04 11
Résumé(disponible en anglais seulement)
Precambrian supercontinents Nuna-Columbia (1.7 to 1.3 billion years ago) and Rodinia (1.1 to 0.7 billion years ago) have been proposed. However, the arrangements of crustal blocks within these supercontinents are poorly known. Huge, dominantly basaltic magmatic outpourings and intrusions, covering up to millions of square kilometres, termed Large Igneous Provinces, typically accompany (super) continent breakup, or attempted breakup and offer an important tool for reconstructing supercontinents. Here we focus on the Large Igneous Province record for Siberia and Laurentia, whose relative position in Nuna-Columbia and Rodinia reconstructions is highly controversial. We present precise geochronology - nine U-Pb and six Ar-Ar ages - on dolerite dykes and sills, along with existing dates from the literature, that constrain the timing of emplacement of Large Igneous Province magmatism in southern Siberia and northern Laurentia between 1,900 and 720 million years ago. We identify four robust age matches between the continents 1,870, 1,750, 1,350 and 720 million years ago, as well as several additional approximate age correlations that indicate southern Siberia and northern Laurentia were probably near neighbours for this 1.2-billion-year interval. Our reconstructions provide a framework for evaluating the shared geological, tectonic and metallogenic histories of these continental blocks. © 2016 Macmillan Publishers Limited.