Signs of the Aeolian Influence on the Formation of Coastal-Marine Sand Deposits in the Permian (Republic of Tatarstan, Russia)

Sandy deposits can have a different genesis and form in different sedimentation environments. The example of the tar sands of the Early Permian age of the Republic of Tatarstan (Russia) shows the possibility of their complex and polygenic formation with the cardinal processing of the initial sediments under the influence of superimposed processes. Using paleogeomorphological analysis and mineralogical and lithological studies, the effect of aeolian processes on the formation of a sandy horizon with a two-layer structure has been established. As a result of the short-term sea regression, the coastal-marine sands were partially above the sea level. The upper part of the sandy sediments was subjected to aeolian processes with the blowing of the clay component from the sands, which led to the formation of two benches - the upper sandy and the lower sandy-clayey ones. The boundary between them is the ancient groundwater table (Stokes surface), which can be used as a reference point in the development of geological models.