Early–Middle Permian Terrigenous Rocks in Southwestern Primorye: Material Composition, Provenances, and Formation Settings

The paper presents the results of studying the material composition of Early–Middle Permian terrigenous rocks of the Reshetnikovo Formation in the Laoeling–Grodekovo terrane of southwestern Primorye. Studies were carried out to reconstruct paleogeodynamic environments of the accumulation of rocks and to determine the tectonic type and composition of parent rocks in sources areas. It has been established that, in terms of mineral and geochemical parameters, sandstones of the Reshetnikovo Formation are petrogenic or “first cycle” rocks. They correspond to arkoses and, only partially, subarkoses and lithite arenites. They are characterized by a fairly high maturity of clastic material. Their appearance is related to the destruction of largely weathered parent rocks in sources areas. Paleogeodynamic interpretation of the obtained data indicates that sedimentation occurred in the Early–Middle Permian in basins of a passive continental margin (intra- and intercontinental rifts and aulacogens). Sedimentation processes were governed mainly by continental sources areas: cratons and uplifted basement blocks, which were projections of the crystalline basement framed by rift zones. Mainly felsic igneous and metamorphic rocks were eroded with the participation of ancient sedimentary rocks. The U–Pb isotopic dating of detrital zircons made it possible to establish the age and possible location of magmatic complexes, whose destruction produced rocks of the Reshetnikovo Formation.