Geological position and composition of sandstones in the Listvenny and Marcheta Formations of the Zasur’ya Series, Gorny Altai

Research subject . Sandstones in the Listvenny and Marcheta Formations of the Zasur’ya Series, Gorny Altai. Aim. Reconstruction of the parent rocks and geodynamic position of the sedimentation basin of sandstones of the Zasur’ya Series. Materials and Methods . The stratigraphic position of greywackes was studied. Petrographic descriptions were carried out using whole-rock compositions obtained by X-ray fluorescence (XFR) analysis. The obtained data were analyzed; classification diagrams were compiled. Results . The geological position of the sandstones of the Listvenny Fm. (Molchanikha Locality) and Marcheta Fm. (Marcheta Locality) shows their sediments as part of an accretionary complex. Planar and vertical cross-sections for both localities were constructed. According to petrographic and geochemical data, the sandstones correspond to greywackes, i.e., first-cycle sedimentation rocks. The provenance of the Listvenny sandstones was dominated by intermediate and felsic rocks. The provenance of the Marcheta sandstones was dominated by mafic to intermediate igneous rocks. Conclusions . According to the studied geological and geochemical data, the greywackes of the Listvenny and Marcheta fms. were formed by destruction of an intra-oceanic arc. The sandstones of the Listvenny Fm. accumulated in a back-arc basin, and the sandstones of the Marcheta Fm. accumulated in a forearc basin.