Amphibolites of the Metamorphic Basement of Wrangel Island: Age, Nature of the Protolith, and Conditions of Metamorphism

Metamorphic rocks from the Neoproterozoic basement of Wrangel Island reveal two distinct metamorphic episodes: one during the Neoproterozoic–Early Paleozoic and another in the Middle Cretaceous. Geochemical analysis indicates that these mafic rocks originated from magmatic melts akin to mid-ocean ridge basalts (MORB), with U–Pb zircon dating pinpointing their protolith age at 617 ± 13 and 698 ± 12 million years ago. The Middle Cretaceous metamorphism, linked to the Chukchi deformation phase, was characterized by greenschist facies conditions and associated with folded nappe structures and extension. Comparison with rocks from the Chukchi Borderland suggests petrographic and chemical similarities, providing insights into the geological evolution of this remote Arctic region.

Sokolov, S. D., Silantyev, S. A., Moiseev, A. V., Tuchkova, M. I., & Verzhbitsky, V. E. (2019). Amphibolites of the Metamorphic Basement of Wrangel Island: Age, Nature of the Protolith, and Conditions of Metamorphism. Geochemistry International, 57(12), 1249–1275. https://doi.org/10.1134/s0016702919120103