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New evidence for the rank of the Wartanian cold period (Pleistocene, MIS 6 ) : a case study from E Poland

Terpiłowski Sławomir, Zieliński Tomasz, Mroczek Przemysław, Zieliński Paweł, Czubla Piotr, Fedorowicz Stanisław

Annales Societatis Geologorum Poloniae

2021

Vol. 91, No. 4

327--345

In the stratigraphic division of the Saalian (Middle Pleistocene) in Europe, the Wartanian cold period has the rank of a stadial of the Odranian Glaciation, correlated with MIS 6. The authors demonstrate the higher rank of this cold period, on the basis of an analysis of the sedimentary succession in eastern Poland, at an exposure of the terminal moraine of the Wartanian ice sheet. At the Wólka Zagórna site, three stratigraphic units were distinguished: A (lower glacigenic deposits – glaciofluvial deposits and subglacial till), A/B (fossil soil of lessivé type), B and C (a periglacial horizon with deflation pavement, involutions, frost-wedge structures and upper glaciofluvial deposits and flow till, with ice-wedge casts). Two distinct periods of climatic cooling, associated with the youngest Saalian ice sheets, were recorded in this succession in E Poland: Odranian (unit A, an ice-sheet transgression marked by the deposition of glaciofluvial deposits dated as 365–226 ka, ending with the deposition of subglacial till), and Wartanian (units B and C, an ice sheet transgression marked by development of a periglacial zone, dated as 180–126 ka, and then deposition of glacigenic sediments at the front of the ice sheet and formation of a marginal moraine). Each of these periods of ice-sheet transgression occurred at a different time (in the MIS 8 and MIS 6 positions) and were separated by a warm period. It is documented by unit A/B – a fossil soil with a very well developed Bt horizon – which attests to its formation in an illuviation process beneath a complex of mixed forests during an interstadial warming that occurred in MIS 7. From this palaeoclimatic reconstruction, it is inferred that the Wartanian cold period should be viewed as a separate glaciation in MIS 6 and the Odranian period should be assigned to MIS 8 in the stratigraphic schema of the Quaternary.

Chronostratigraphy of Late Glacial aeolian activity in SW Poland – A case study from the Niemodlin Plateau

Moska Piotr, Jary Zdzisław, Sokołowski Robert Jan, Poręba Grzegorz, Raczyk Jerzy, Krawczyk Marcin, Skurzyński Jacek, Zieliński Paweł, Michczyński Adam, Tudyka Konrad, Adamiec Grzegorz, Piotrowska Natalia, Pawełczyk Fatima, Łopuch Michał, Szymak Agnieszka, Ryzner Kamila

Geochronometria

2020

Vol. 47, no.1

124--137

The stratigraphy of Late Pleniglacial and Late Glacial fluvio-to-aeolian succession was investigated in two sites located at the Niemodlin Plateau, SW Poland. Lithofacial analysis was used for the reconstruction of sedimentary environments. An absolute chronology for climatic change and the resulting environmental changes were determined based on optically stimulated luminescence (OSL – nine samples) and radiocarbon (three samples) dating methods. Four phases of changes in sedimentary environments were established. The first depositional phase correlates with the Last Permafrost Maximum (24−17 ka) based on the type and size of the periglacial structures, which aggraded under continuous permafrost conditions. During 17.5−15.5 ka (upper Late Pleniglacial), a stratigraphic gap was detected, owing to a break in the deposition on the interfluve area. The second depositional phase took place during 15.5−13.5 ka. During this phase, the first part of the dune formation (Przechód site) and fluvio-aeolian cover (Siedliska site) was deposited. The sedimentary processes continued throughout the entire Bølling interstadial and Older Dryas. In the third phase (Allerød interstadial), soil formation took place. At the Siedliska site, palaeosol represented Usselo soil type, whereas at the Przechód site, there was a colluvial type of soil. The last phase (Younger Dryas) is represented by the main phase of dune formation in both sites. After the Younger Dryas, no aeolian activity was detected. High compliance with both absolute dating methods was noticed.

The polar decomposition : properties, applications and algorithms

Zieliński Paweł, Ziętak Krystyna

Matematyka Stosowana : matematyka dla społeczeństwa

1995

Nr 38

23--49

In the paper we review the numerical methods for computing the polar decomposition of a matrix. Numerical tests comparing these methods are included. Moreover, the applications of the polar decomposition and the most important its properties are mentioned.