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An examination of the glaciomarginal fan of the Odranian glaciation at the Mokrzeszów site, Sudetic Foreland, SW Poland

Krzyszkowski Dariusz, Wachecka-Kotkowska Lucyna, Skurzyński Jacek

Geology, Geophysics and Environment

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2022

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Vol. 48, no. 3

287--318

EN

The article presents the results of research from the Mokrzeszów site in the Sudetic Foreland. Lithopetrographic and sedimentological analyses of sediments from the Middle Polish Glaciations (Early Saalian, Odranian, MIS6) in this area indicate the overrepresentation (90–95%) of large Scandinavian erratics. The deposits, representing a repetitive sequence of Gp-Gms-Sp-Sh/Sr(Dmm) lithofacies, accumulated during at least two episodes of glacial outburst floods and six sedimentary cycles. High-energy flows are estimated for the Gms and Gp facies at about 5 m∙s−1 and low-energy flows indicate 0.8 m∙s−1 for the Sp/Sh/Sr facies, to the lack of flow (Fm). The sedimentary sequences confirm the existence of a fan, which may have originated as a subaqueous steep coarse-grained fan in glacial-flow-lake-outburst floods that formed between the ice sheet front and the morphotectonic edge of the Sudetic Marginal Fault line and within the Roztoka-Mokrzeszów Graben, or as an aerial, piedmont fan on the Sudetic Marginal Fault edge. The sediments show discontinuous deformations – gently sloping faults and fractures from glacioisostatic stresses. The fault activity is probably related to the reactivation of the faults due to ice loading during or after the older Saalian glaciation.

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Analiza petrograficzna narzutniaków w żwirowni Łubienica-Superunki oraz ich skandynawskie obszary alimentacyjne

Górska-Zabielska Maria, Smolska Ewa, Wachecka-Kotkowska Lucyna

Przegląd Geologiczny

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2021

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Vol. 69, nr 1

43--54

EN

Petrographic studies covered 20-60 mm coarse gravel and 4-10 mm medium-grained fractions of two till horizons (units ŁS II and ŁS IV) and two beds of sand-gravelly-outwash deposits(units ŁS I and ŁS III) associated with the Odra Glaciation (MIS6) in Łubienica-Superunki on the North Mazovian Lowland. Regardless of the facies type and grain sise, crystalline rocks dominate over all other petrographic groups in all samples. The percentage of crystalline rocks is greater among coarse gravel (average 74.7%) than among medium-grain gravel (average 67.8%). The share of carbonate rocks is limited only to the both lower units ŁS I and ŁS II. The upper units (ŁS III and ŁS IV) are deprived of these rocks, both in the medium and coarse gravel fraction. Sandstones, presented in all samples, were in the range of 5-20%. From the other petrographic groups, individual chalk limestones clasts, dolomites, flints and quartz grains were identified in the material. The indicator erratics were identified in all four units. Their percentage content stands for 10-18% of the total sample of coarse-grained fraction. Among them, the most common were the erratics derived from the Åland Islands, and then from the area of south-eastern Sweden (Smaland) and from Dalarna in central Sweden. Amongst the erratics with limited indicator significance, Lower Paleozoic limestones and Jotnian sandstones were most frequent. Single fragments of Ordovician red and Paleoporella limestone were present. These rocks, including the Lower Paleozoic grey limestone, occurred only in thelowerunits(ŁS I and ŁS II). The results of the research suggest that the two lower sediment units should be correlated with a ice-sheet advance (Middle Polish Complex, Odranian Stadial?), and the two upper ones - with a separate, subsequent advancement (Wartanian?). The paper is another methodological contribution to the consideration of abandoning the tedious testing of glacial till and focusing on a much faster petrographic analysis of fluvioglacial sediments associated with the same ice sheet. This is demonstrated by the comparable results of the petrographic analysis of short transport outwash sediments and till from a single glacial period.

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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

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2021

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Vol. 91, No. 4

327--345

EN

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.

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Struktury glacitektoniczne w osadach plejstoceńskich kopalni węgla brunatnego Bełchatów

Bruj M., Krysiak Z.

Prace Państwowego Instytutu Geologicznego

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2009

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T. 194

7--26

PL

W artykule przedstawiono wyniki badań drobnych struktur glacitektonicznych w osadach środkowego plejstocenu zachodniej części kopalni Bełchatów. Podstawową metodą badań była analiza mezostrukturalna. Większe nagromadzenia struktur glacitektonicznych są związane z obecnością stref dyslokacji w podłożu. W profilu pionowym najwięcej struktur glacitektonicznych pojawia się pod gliną górną (zlodowacenie warty) i w stropie gliny dolnej (zlodowacenie odry/warty?). Zmiana stylu deformacji na niewielkich odległościach wynika z różnic w litologii osadów i zawartości wody porowej. Konsekwencją tego jest różna podatność na odkształcenia. Wyniki analizy mezostrukturalnej wykazały, że kierunek kompresji horyzontalnej (SH) zmieniał się diachronicznie: od N–S, NE–SW (na dole profilu) przez NW–SE do W–E (w stropie). Skręcenie pola kompresji o 90° zinterpretowano jako wynik nakładania się nacisków lądolodu zlodowacenia warty (lobu Widawki) i reakcja ram tektonicznych rowu Bełchatowa na ten nacisk.

EN

The article presents results of study of small glaciotectonic structures in Middle Pleistocene deposits of the Bełchatówmine (western part). Mesostructural analysis was a basic method of study. The main cause of zonal occurrence of glaciotectonic structures was structural setting of the basement. In a vertical section, most of glaciotectonic structures appear under the upper till and at the top of the lower till. A change in deformational style at a small distance is due to lithological differences resulting from different resistance. A change in pore water pressure was also important. Results of mesostructural analysis proved that horizontal compression (SH) in a vertical section was diachronically changed: from N–S and NE–SW (at the bottom) through NW–SE (in the middle) to W–E (at the top). This gradual torsion of the compression stress field is interpreted as being a result of overlapping of glacier pressure (Saalian –Widawka lobe – W–E direction) onto the Bełchatów graben structure and its reaction.