D.V. RYABCHUK, A.YU. SERGEEV, V.A. ZHAMOIDA, E.O. PETROV, L.M. BUDANOV (VSEGEI), A.V. KREK, E.S. BUBNOVA, A.R. DANCHENKOV (IO RAS), I.A. NEEVIN, O.A. KOVALEVA (VSEGEI)

New data on deglaciation in the Eastern Gulf of Finland: results of high-resolution geological mapping

A procedure of high-resolution marine geological mapping (scale 1:25,000–1:10,000) was developed based on results of multibeam echosounding, acoustic-seismic profiling and various sediment sampling technics during joint cruises of IO RAS and VSEGEI in 2017–2019 in the Eastern Gulf of Finland. The research allowed receiving new data about the Gulf of Finland basin deglaciation, to establish sedimentological processes’ features and impact of exogenous processes on the geological environment. Submerged end moraine, drumlins, eskers, De Geer moraine were mapped for the first time in the study area. Analyses of acoustic-seismic data, supported by sediment sampling, allowed revealing several erosion layers, interpreted as results of relative fall of sea level in the Holocene. The obtained results can be used in the State Geological Map monitoring program.
Keywords: Late Pleistocene, De Geer moraine, end-moraine complex, acoustic-seismic profiling, multibeam echosounding.