Crustal structure of the Volgo–Uralian subcraton revealed by inverse and forward gravity modelling

Abstract. Volgo–Uralia is a Neoarchaean easternmost part of the East European craton. Recent seismic studies Volgo–Uralian region provided new insights into crustal structure this area. In study, we combine satellite gravity and data in common workflow to perform complex study structure, which useful for further basin analysis light, model subcraton presented from step-wise approach: (1) inverse modelling followed by (2) 3D forward modelling. First, inversion gradient was applied determine Moho depth Density contrasts between crust mantle were varied laterally according tectonic units present region, constrained available active data. The discontinuity obtained consequently modified complemented order define complete adding information on sedimentary cover, upper crust, lower lithospheric layers process modelling, where both constraints respected. shows thickness variations 32 more than 55 km certain areas. thinnest with below 40 found beneath Precaspian basin, covered thick layer. thickest located underneath Ural Mountains as well centre subcraton. areas exceeds 50 km. At same time, initial has shown misfit ca. 95 mGal measured Bouguer anomaly calculated field central area This interpreted modelled high-density possibly represents underplated material. Our preferred respects reflects main geological features thickening cratons under thinning along Palaeoproterozoic rifts, Pre-Urals foredeep.