Age, Composition, and Geodynamic Setting of Granitoids and Dike Rocks from Cape Svyatoy Nos, Eastern Arctic

摘要

Granitoids and dikes of Svyatoy Nos pluton of Cape Svyatoy Nos in the northwestern part of Verkhoyansk-Kolyma folded area, cutting terrigenous and volcanogenic-sedimentary rocks of Upper Jurassic-Lower Cretaceous, are considered. Obtained U-Pb SIMS geochronological data on zircons from granitoids and dike rocks indicate, that their crystallization ages correspond to Aptian-Albian (119-111 Ma). Petrography and geochemical affinitites of rocks allow to refer granitoids and felsic dikes to I-type granites. Similarity in chemical composition with coeval granitoids of Great Lyakhovsky Island, the most northern member of Chokhchuro-Chokurdakhsky submeridional belt of granitoids and Aptian-Albian granitoids of sublatitudinal belt of Anyui-Chukotka fold belt is shown. Earlier it was established by many authors, that intrusion of Aptian-Albian granitoids and dikes (117-105 Ma) on the Arctic margin of Chukotka and in the northwestern part of Verkhoyansk-Kolyma folded area occurred during extension. Aptian-Albian age, post-shortening character of intrusion and similarity of Svyatoy Nos granitoids in chemical composition with mentioned above Aptian-Albian granitoids allow to refer them to a single stage of postcollisional extension.