Present-day structure and stages of tectonic evolution of Wrangel Island, Russian eastern Arctic Region

Abstract

Present-day structure of Wrangel Island was formed during two main stages of Mesozoic-Cenozoic deformation. The general fold-thrust structural grain of the island, characterized by northern vergence and complicated by NW-trending right-lateral strike-slip faults, originated in the post-Triassic. Mesostructural data indicate a near-meridional orientation of regional compression. This deformation stage was related to the orogeny in the New Siberian-Chukchi Fold System, which occurred at the end of Neocomian in the pre-Aptian. The next stage was characterized by a near-meridional and NNW-SSE extension established by superposition of normal, right-lateral strike-slip, and pull-apart kinematics upon the former fold-thrust structure. Comparison of the structural and the published seismic data allows us to suggest the later stage of compression to be in the Late Cretacous-Paleocene, which is correlated to the Mid-Brookian angular unconformity in Arctic Alaska and North Chukchi Basin. Accordingly, the Cenozoic age (since Paleocene-Eocene) of the main extension and right-lateral transtension most likely corresponds to opening of the South Chukchi (Hope) Basin localized immediately to the south of the Wrangel-Herald Arch (High). The difference in structural patterns of the Silurian-Lower Devonian and the Upper Devonian (?)-Triassic rocks is evidence for deformation related to the Ellesmerian Orogeny in the Middle-Late Devonian.