Provenance of silt and clay within sandy deposits of the Lithuanian coastal zone (Baltic Sea)

Mineralogical analysis of the silt and clay fraction of sandy deposits of 37 surface samples and grain-size data are used to interpret sediment sources acting in the SE Baltic Sea along the Lithuanian coast. Mineralogical composition was determined using X-ray diffraction (XRD) methods. Grain-size distribution was obtained by standard dry sieving and pipette techniques. For identification of sources we combined known compositional information of possible sources with logical models for mineral combinations related to regional geological provinces and processes, supported by results of correlation and factor (principal component) analyses between minerals, grain-size parameters and bathymetric features of the area. The main sources supplying sediment into the area are: 1) the Sambian Peninsula to the south, 2) the Nemunas River, whose discharge passes through the Curonian Lagoon, and 3) Late Pleistocene till erosion on the sea floor in the north and at the Olando Kepure shore cliffs. The general pattern of spatial distribution related to the identified sources for the fine-grained sediment fraction is interpreted as a shore-parallel transport of suspended matter, flowing northwards in the southeastern part of the Baltic Sea.