Mesozoic deformation, Taimyr & the development of the Amerasia Basin

A joint Russian-Swedish expedition (summer 2010) to investigate the tectonomagmatic and sedimentary history of southeast Taimyr provides crucial constraints on the timing of deformation and potential links with other contractional deformation belts in the Arctic. In south-central Taimyr most deformation is late Triassic to earliest Jurassic, with undeformed Jurassic sediments resting on deformed older rocks. However, in southeast Taimyr along the Chernokrebetnaya River, Jurassic and possibly Cretaceous strata also appear to be folded.

The 2010 expedition aimed to determine the nature of this deformation and compare it to deformation elsewhere in Taimyr. Preliminary results suggest that partially unconsolidated and little deformed Jurassic sediments overlie consolidated and cleaved pre-Jurassic strata, indicating that post-Jurassic folding apparently nucleated on earlier Mesozoic structures. These observations are consistent with a northward continuation of diachronous and polyphase Uralian orogenesis, which has long been debated, and supports recent models in which Mesozoic deformation is at least as important as earlier recognized late Paleozoic deformation in more southern parts of the Uralian orogen.

This is a CALE contribution.