Development of Sand Deposits in the Southern Part of the Curonian Spit

As part of paleogeographic studies on the Curonian Spit (geological section GS 024), a coastal section was studied from the sea in the area of the village of Lesnoy in the place where relict lagoon oozes come out. The granulometric, chemical, and mineral compositions of slope sands were studied for the first time. Heterogeneous conditions for the formation of sand strata were confirmed. A high probability of a secondary change in the composition of sediments as a result of weathering processes was revealed. The results of the study indicate a gradual advance of sand deposits on the coastal part of the lagoon, which began about 10 ka ago. Differentiation of the sand stratum into lower and upper parts with respect to an interlayer marker of coarse-grained sand identified in the section may reflect different stages of generation of the sand stratum: from an alleged shallow-water swell formed during sea level rise to beach and eolian sands.