Types of sediments and sections in the upper quaternary cover and geological stability of the Curonian Spit (Baltic Sea)

Abstract

Data on types of Holocene sediments overlying the Upper Pleistocene glacial sediments and constituting the Curonian (Kurshskaya) Spit are summarized to assess its geological stability. The data made it possible to define and describe four main types of sections: (1) peaty, (2) peaty-sandy, (3) gravelly-sandy, (4) muddy-sandy-sapropelic. These spit sections are correlated with the counterparts in adjacent areas of the Baltic Sea and Curonian Lagoon (Kurshskaya Bay). The role of different sources is elucidated for sedimentary material in the spit. Data on recent processes of erosion and accumulation in coastal areas of the spit are compared with types of sediments and sections in the spit and adjacent areas of the sea and lagoon. It is established that paleostraits filled with peat and sapropel represent low-stability areas of the spit. Various scenarios of the spit evolution in response to high sea-level rise are considered.