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Model litofacjalny stożka ujściowego Wisły jako zapis interakcji środowiska lądowego i morskiego

Koszka-Maroń D.

Przegląd Geologiczny

2016

Vol. 64, nr 5

315--327

The study area (20 km2) covers part of the Vistula River's delta front and prodelta, active since 1895. The Vistula river-mouth fan is a unique area of intense accumulation of clastic material, whose development can be investigated from a precisely defined moment in the history of its origin to the present day. The research has resulted in a morphodynamic model (based on bathymetric plans of the contemporary Vistula mouth area over the period of 1894–2000) and a facies model of the Vistula mouth fan. The analysis of the morphometric models shows that 105 years after the Vistula Cross-Cut was opened, the volume of the sediment accumulated in the fan was 133.39 million m3 and the rate of accretion has decreased. Facial models were created on the basis of results of lithological analysis of sediments. The Vistula mouth fan is built of delta front sediments represented mainly by sand facies (fine-, medium- and coarse-grained, locally with gravel, as well as marine and freshwater mollusc shells), only locally by silt facies. The thickness of the river-mouth fan sands is 11–15 m. The prodelta sediments are found on the fan's forefield within a depth zone of 12–16 m, and they also underlie the fan sediment. Their thickness is up to ca. 10 m. Cluster analysis of the individual grain-size distributions made it possible to distinguish two lithofacies in the Vistula mouth fan: lithofacies A (fine-grained sand, silty sands, clayey silt) and lithofacies B (medium-grained and coarse-grained sand). This allowed reconstructing the processes which has taken place over the last 100 years, and to forecast future changes in the development of the active part of the Vistula Delta.

Recent development of the Vistula River outlet

Graniczny M., Janicki T., Kowalski Z., Koszka-Maroń D., Jegliński W., Uścinowicz Sz., Zachowicz J.

Polish Geological Institute Special Papers

2004

Vol. 11

103--107

The Vistula River mouth is an unique example of river’s outlet observed since the birth in 1895 to present day. There is a large documentation of morphological changes in the outlet area. In 1895, a 7 kilometres canal was dug into which the waters of the Vistula were let in. Since 1895, most of the water discharge and all sediment transport reach the Gulf through artificial channel c. 20 km east of Gdańsk. During the last 100 years, the shoreline has been shifted seaward c. 1.5 km on the eastern side, to c 2.5 km on the western side of the Vistula mouth. Isobath of 5 m moved seaward c. 3 km and isobaths of 10 and 15 m shifted 2.5 km. During the years 1895-1997, land area accreted to 3,019,000 m2. The volume of the river-outlet cone in the year 2000 was 133.39 mln m3 and the average rate of sediment growth over the 105 years was c. 1.27 mln m3 per year.