Squeezed diapirs of the Chernyshev Swell (the Timan Pechora Basin): integrated study and petroleum habitat

A multidisciplinary study including 2D and 3D seismic surveying, magnetotelluric, gravimetric, and magnetometric measurements was conducted to unravel the geological structure of the Chernyshev Swell's and the adjacent areas of the Kosyu-Rogov Foredeep Basin. Integrated interpretation of these data and vintage information allowed the introduction of a new concept of this areas' structural development. It suggests that the structural evolution was largely influenced by the diapirism of the Upper Ordovician salt. The salt started to move towards the Chernyshev Swell from the Kosyu-Rogov Foredeep Basin with the development of diapiric walls as early as the Silurian. The salt walls underwent compression during the Uralian collisional folding from the second half of the Artinskian age. It resulted in the squeezing of the diapirs and salt's extrusion to the surface, followed by extensive thrusting. The salt-related deformations continued throughout the Mesozoic and Cenozoic activated by the intraplate stresses. The study area's structural evolution created favourable conditions for the development of a large oil and gas trap in the 3-way structural closure juxtaposed against the thrust zone. It includes regionally productive suprasalt Silu-rian-Permian deposits sealed updip by the allochthonous salt. © 2021, VNIGNI-2 OOO. All rights reserved.