Zyryanka Basin Composite Tectono-Sedimentary Element, Northeastern Asia

Abstract

Abstract Zyryanka Composite Tectono-Sedimentary Element is located in the NE Asia. It consists of a synonymous sedimentary basin, that is one of the least studied onshore basins in the NE Asia due to its remoteness and scarcity of wells and geophysical data. The basin evolved through 4 episodes of subsidence and two episodes of contraction. The Late Jurassic to Late Cretaceous subsidence is inferred to be caused by tectonic loading during contraction events within the Verkhoyansk-Kolyma Orogen, which led to the deposition of up to 10 km of predominantly continental siliciclastic strata. In the Cenozoic, the basin evolved in a post-orogenic intracontinental setting and accumulated a 2-3 km thick succession of continental siliciclastic strata. In the Oligocene to mid-Miocene, the basin evolved in a contractional setting caused by the convergence between Eurasian and North American lithospheric plates and underwent a contractional deformation in the Middle Miocene. We recognise four individual tectono-sedimentary elements that are related to different stages of the basin's evolution. The basin contains significant coal resources. It was also considered a potential prospective area for the formation of hydrocarbon accumulations especially in its Upper Jurassic-Cretaceous strata; however, drilled wells did not encounter oil or gas-bearing reservoirs.