Wyniki wyszukiwania - BazTech

1

New insights into the genesis of the “Poznań clays” – upper neogene of Poland

Maciaszek Piotr, Chomiak Lilianna, Urbański Paweł, Widera Marek

Civil and Environmental Engineering Reports

|

2020

|

Vol. 30, no. 1

18--32

EN

The present study focuses on the upper Neogene deposits, called the “Poznań Clays”, that cover more than 75,000 km2 of Poland. They are situated between the first midPolish lignite seam and the glaciogenic deposits of the Pleistocene age. Lithostratigraphically, the “Poznań Clays” belong to the uppermost portion of the lignite-bearing Grey Clays Member and the whole Wielkopolska Member (Poznań Formation). The examined fine-grained sediments include mud-rich floodplain deposits with palaeosol remnants and large sandy-muddy or muddy palaeochannel bodies. Therefore, taking into account facies analysis, cross-sectional geometry, and the planform of the palaeochannels, it can be stated that the “Poznań Clays” formed in the environment of a late Neogene anastomosing river.

2

Main determinants of the grain size distribution of overbank deposits in Poland : an overview of literature on models of sedimentation

Szmańda J. B.

Geological Quarterly

|

2018

|

Vol. 62, No. 4

873--880

EN

The article describes the most important features of the grain size distribution of overbank deposits (madas) of Polish rivers. The most important characteristics of their deposition and the factors determining the variability of the grain size distribution of overbank deposits are indicated. Almost all grain fractions distinguished in nature, i.e. cobbles, gravels, sands, silts, and clays, occur in the overbank deposits of Polish rivers. The sandy fraction dominates in overbank sediments, which contradicts their widespread recognition as silty-clayey (mud) sediments. The change in the proportion of these fractions (the formation of different types of lithological overbank deposits) is caused by a change in the conditions of sediment transport dependent on six factors: (1) decrease in water flow velocity over a floodplain along with an increase in the distance from the river channel, (2) change in water flow velocity during a single flood (stages of a flood), (3) the diversity of the floodplain relief, (4) changes in the forest cover of the river basin (catchment), (5) change in the longitudinal slope and (6) width of floodplains.

3

Wpływ regulacji koryta na warunki sedymentacji osadów na równinie zalewowej dolnego Dunajca

Liro M.

Przegląd Geologiczny

|

2012

|

Vol. 60, nr 7

380--386

EN

In the last century the Dunajec channel in its lower river course was considerably transformed due to channelization works. The former multi-thread river channel was replaced by a single one, resulting in abandonment of side channels. Groynes were constructed on both main and side channel. Quick filling up of the inter-groyne basins reduced channel width and capacity. In the study area, a side channel with groynes was abandoned and filled up. The aim of this study was to reconstruct the rate and depositional conditions of the sediments infilling the abandoned channel. These sediments are 215-222 cm thick and were deposited at an average rate of 5-5.2 cm/year. Their sedimentary environment was inferred based on a C/M diagram. The depositional conditions in the abandoned channel were determined by two major factors: distance to the active channel and difference in elevation between depositional surface and active channel. Close to the active channel, 61% of sediment was deposited from suspension and 39% by traction current. At a distance of 200 m to the active channel, 100% of sediment was deposited from suspension, with 25% falling from pelagic suspension. At an early stage of infilling of abandoned channel, the depositional flows are more energetic and the deposition rate is higher than in the later stage. The investigated sediments are an example of accumulation induced by channelization works. The spatial distribution of these fine-grained, quickly deposited sediments is determined by the course of the abandoned channel.

4

Górnoholoceńskie i współczesne formy i osady pozakorytowe w dolinie środkowej Wieprzy

Kaczmarzyk J., Florek W., Olszak I. J.

Landform Analysis

|

2008

|

Vol. 7

80--94

PL

Celem autorów było rozpoznanie osadów pozakorytowych w dolinie środkowej Wieprzy i możliwie dokładne określenie ich wieku oraz miejsc i warunków ich akumulacji na równinie zalewowej. Zastosowano przy tym zestaw metod geomorfologicznych i geologicznych odnoszących się do analizy form występujących na równinie zalewowej i i budujących je osadów.Wcelu określenia ich wieku wykorzystano datowania radiowęglowe, datowania archeologiczne i w odniesieniu do osadów mineralnych – metodę termoluminescencyjną. Analizom poddano osady basenu powodziowego, osady wypełniające różnowiekowe paleomeandry oraz subfosylne i współczesne osady pozakorytowe.

EN

The aim of the study has been to recognize overbank deposits in the middle Wieprza valley, including their precise dating and assessment of local conditions of sedimentation. It is based on geomorphological and geological research of floodplain landforms and deposits. Ages have been determined using radiocarbon method, archaeological dating and, for minerogenic deposits, TL dating. Analyses have been performed on floodplain basin deposits, palaeomeander infills, and subfossil and recent overbank deposits. The studied palaeomeanders have variable infills from various periods of the Sub-Atlantic. They are accompanied by diversified point bar deposits. Floodplain basin deposits have a similar, Sub-Atlantic age. Both types of deposits are overlain by flood deposits, which have accumulated since the early Middle Ages. Contemporary flood deposits of the Wieprza river differ from the sub-fossil ones through more restricted occurrence, resultant from channelization and channel incision. Therefore, in comparison to the pre-channelization period, the extent of floods is smaller and does not encompass the entire Holocene floodplain. Flood overbank deposits form only in the immediate vicinity of the channel.

5

Age of the Vistula River overbank deposits in Toruń

Szmańda J. B., Oczkowski H. L., Przegiętka K. R.

Geochronometria

|

2004

|

Vol. 23

35-38

EN

The paper presents luminescence dates of the overbank deposits accumulated on the Bazarowa Holm in Toruń. From these results we conclude that the flood deposits accumulation was started in this part of the Vistula river valley between 1000 and 2000 years ago. Deforestation and following increase of the floods. events intensity, which occurred in early Middle Ages, may be the possible reasons for the aggradation phase on the flood plane.

6

Sedymentacja pozakorytowa aluwiów w strefie międzywala Wisły w Kotlinie Oświęcimskiej

Czajka A.

Przegląd Geologiczny

|

2000

|

Vol. 48, nr 3

263-267

PL

Naturalne procesy erozji i sedymentacji zachodzące na równinie zalewowej Wisły w Kotlinie Oświęcimskiej zostały przerwane w XIX w. w momencie rozpoczęcia zabudowy hydrotechnicznej rzeki. Zmiany użytkowania ziemi w dorzeczu i zintensyfikowanie dostawy materiału do koryta oraz zwężenie równiny zalewowej poprzez zbudowanie wałów przeciwpowodziowych spowodowały zmianą sposobu sedymentacji aluwiów oraz wzrost tempa tego procesu. Miał węglowy obecny w osadach od I-szej połowy XIX w. może stanowić dobry wskaźnik wieku badanych osadów.

EN

The natural processes of erosion and sedimentation at the Vistula River floodplain in Oświęcim Basin were interrupted in the 19th century. This was caused by hydrotechnical constructions, such as dams and embankments. Agricultural changes in the upper Vistula catchment caused intensification of soil erosion and an increase of transported debris. Embankment construction narrowed the floodplain. It changed the way of alluvial sedimentation. Coal dust which has occurred in sediment since the beginning of the I9'h century is a good age indicator