Abstract <p>New U–Pb zircon dating of rock samples from the core of the Koolen granite–gneiss dome in Chukotka yielded a Neoproterozoic age (650–530 Ma) for orthogneisses and a Devonian age (390–360 Ma) for granitoids. Devonian granites and quartz monzonites are attributed to the peraluminum magnesian calc-alkaline varieties of volcanic arc granitoids formed during the Ellesmerian orogeny of the Arctic. All rocks of the complex show evidence of having been subjected to the last peak of metamorphism and extensional deformation in the Early Cretaceous, as follows from the age of syndeformational pegmatites.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Neoproterozoic and Devonian Granites of the Koolen Granite–Gneiss Dome, Arctic Chukotka

  • V. V. Akinin,
  • E. P. Isaeva,
  • G. O. Polzunenkov

摘要

Abstract

New U–Pb zircon dating of rock samples from the core of the Koolen granite–gneiss dome in Chukotka yielded a Neoproterozoic age (650–530 Ma) for orthogneisses and a Devonian age (390–360 Ma) for granitoids. Devonian granites and quartz monzonites are attributed to the peraluminum magnesian calc-alkaline varieties of volcanic arc granitoids formed during the Ellesmerian orogeny of the Arctic. All rocks of the complex show evidence of having been subjected to the last peak of metamorphism and extensional deformation in the Early Cretaceous, as follows from the age of syndeformational pegmatites.