Lithology of the Upper Triassic Sedimentary Rocks of Chukotka and Wrangel Island and Their Relationship with Coeval Rocks of the Eastern Arctic

A new correlation between Upper Triassic sedimentary rocks from Wrangel Island and the Chukchi Peninsula (Chukotka) reveals that these deposits, though geographically distinct, share similar isotopic, petrographic, and geochemical features. The study demonstrates that these sands originated from a single sedimentary basin, with Wrangel Island's sediments forming in shallow-water prodeltas while Chukotka's accumulated in deeper-water environments. Notably, the latest Triassic saw an increase in sandy material but a decrease in grain size, suggesting reduced tectonic activity and prolonged weathering of granitoid, metamorphic, and metavolcanic source rocks. These findings extend correlations to coeval rocks in the Sverdrup Basin and northern Alaska, providing insights into the paleogeographic evolution of the Eastern Arctic.

Tuchkova, M. I., Sokolov, S. D., Moiseev, A. V., Verzhbitskii, V. E., Kostyleva, V. V., & Vatrushkina, E. V. (2023). Lithology of the Upper Triassic Sedimentary Rocks of Chukotka and Wrangel Island and Their Relationship with Coeval Rocks of the Eastern Arctic. Russian Geology and Geophysics, 64(3), 270–291. https://doi.org/10.2113/rgg20224460