Gravity modeling of the Earth’s crust structure along the Khyriv—Rava-Ruska—Velyki Mosty profile

Abstract

We used 2D gravity modeling to investigate the structural features of the Earth’s crust and upper mantle in the junction zone of the outer Ukrainian Carpathians and the East European Platform along the Khyriv―Rava-Ruska―Velyki Mosty line. The profile passes through a poorly studied and complex structure of the border between Ukraine and Poland: it crosses the Folded Carpathians, the Precarpathian Trough, the Rava-Ruska Zone, and ends in the outer zone of the Lviv Trough. As the initial model of the crust, a deep seismic-geological section along the eponymous traverse SG-1(66) was used. The modeling results confirmed the seismic-geological data on the depths of the Carpathian base and the basement surface along the traverse, identified the main tectonic blocks and deep faults of the Earth’s crust, and determined the densities of the sedimentary complex and basement rocks. The lower crust and upper mantle under the Folded Carpathians have higher density. The reflection in the anomalous gravity field of tectonic units of the Folded Carpathians, the predicted Turkivskyi Paraautochthonous Complex, as well as deep mafic magmatic formations between the Rava-Ruskyi and Velykomostivskyi Faults, was investigated. Under the regional negative gravity anomalies, a deepening of the Moho boundary was detected under the Folded Carpathians and the Teisseyre-Tornquist Zone up to 45 km and 50 km, respectively. The results obtained are consistent with foreign and domestic geophysical materials.