Timing and style of deglaciation of north eastern Poland from cosmogenic 36Cl dating of glacial and glaciofluvial deposits

Determining the age of glacial and glaciofluvial deposits is necessary to better under stand the deglaciation of north eastern Po land. Cosmogenic 36Cl, accumulated in boulders and matrix, suggests that in heritance and erosion affect cosmogenic inventories and must be taken into account when calculating exposure ages of land forms. A simple approach to detect and distinguish between the two effects, by comparing the inventories of 36Cl in boulders and matrix, allows us to compute appropriate corrections to apparent (uncorrected) ages and to determine model (corrected) exposure ages of the deposits. Apparent cosmogenic 36Cl ages fall in the range between 11 ky and 28 ky (1 ky = 1000 calibrated 36Cl years), pointing, correctly, to the end of the last glaciation, and correlate with oxygen isotope stage 2 (OIS 2). Model ages of glacial and glaciofluvial depos its fall into one of three time intervals. The oldest erratics, 27-28 ky (Kruszki and Bachanowo 1), date the advance of the Weichselian ice sheet. They are older than the surrounding surfaces, which con firms the existence of nunataks during later phases of the last glaciation. The main belts of recessional moraines formed 19.7 š 1.0 ky ago (Gremzdy Polskie) and 17.9 š 1.3 ky ago (Łopuchowo 2 and Gulbieniszki), and the last ice melted 14.4 š 1.0 ky ago (Łopuchowo 1). Erosional terraces in the Czarna Hańcza valley were formed 14.7 š 0.9 ky ago (Bachanowo 2) and 14.4 š 1.0 ky ago (Bachanowo 3), probably by the melt waters from the last ice in the area. Our results suggest that different parts of the southern margin of the Fennoscandian Ice Sheet advanced and re treated independently, supporting the idea that the deposits at the southern margin of the Scandinavian Ice Sheet are not synchronous

Record and palaeogeographical implications of Pleistocene periglacial processes in the Drohiczyn Plateau, Podlasie Lowland (Eastern Poland)

The paper describes 51 ice-wedge casts from Wierzchuca Nagórna village near Drohiczyn town in the Podlasie Lowland in Eastern Poland. The structures are preserved in a till of theWartanian Glaciation. In the exposure the mean distance between them is 1.7 m; their mean length is 1 m, and their width ranges within 0.2–0.5 m. Most of the structures are typically wedge-shaped, although in some cases less regular pockets or veins are also observed. Some of the casts display a complex origin. They are filledmostly by fine-grained sand, in the lower parts with wind-corroded grains, as well as by sand with gravel from the overlying deposits. Near the ice-wedge casts, traces of frost swelling, uplift and sorting in permafrost conditions, as well as of an active layer are preserved. The thickness of the permafrost active layer, as preserved, is about 0.5–0.7 m. The formation of ice-wedges reflects periglacial conditions during the Vistulian (Weichselian) Glaciation. Three palaeogeographical alternatives are discussed. Probably, the lack of traces of periglacial activity from the Wartanian Glaciation is a result of plateau denudation. The range of this denudation has also been estimated

Advantages of high-resolution digital terrain model (DTM) analysis in geological cartography

Современные проблемы геологического картирования: материалы Х Университетских геол. чтений, 14 15 апр. 2016 г., Минск, Беларусь / В.И. Зуй (отв. ред.) [и др.]. – Минск: Изд. центр БГУ, 2016. – 182 с

Outline of Quaternary glaciations in the Tatra Mts. : their development, age and limits

Geomorphological and geological data collected over many years suggest at least eight episodes during which the Tatra Mts. were glaciated during the Quaternary. Evidence of glaciers can be found both in the Slovakian and Polish parts of the mountains as glaciofluvial deposits located at different altitudes, and in some cases also as terminal and lateral moraines. There are no moraines for the three oldest glaciations, Biber, Donau and Günz, maybe as a result of less intense development of glaciers. During the Mindel (Sanian 2) Glaciation the glaciers occuped a larger area in the High Tatra Mts. in comparison to the Western Tatra Mts., whereas during the succeeding younger pre-Riss (Liviecian) Glaciation their development was more restricted. A greater extent of the Tatra Mts. glaciers occurred again during the Riss I (Odranian) Glaciation, while they were less extensive during the Riss II (Wartanian) Glaciation. During the Würm (Vistulian) Glaciation the glaciers were surprisingly large. This might have resulted from many factors, including changes in atmospheric circulation responsible for the distribution of precipitation, as well as changes in the position of the permanent snow limit due to climatic changes and/or neotectonic movements. Glaciers finally retreated from the Tatra Mts. by the end of the pre-optimal part of the Holocene

Upper Pleistocene palaeoenvironmental changes at the Zwierzyniec site, Central Poland

The paper presents the data on an Eemian–Late Glacial sedimentary sequence from the Zwierzyniec site, central Poland. A number of boreholes document one or two organic layers that occur beneath one or two horizons of clayey and silty deposits of ice-dammed lakes. This study demonstrates to which extent the Zwierzyniec site can contribute to a better understanding of the palaeoenvironmental changes during the Eemian–Vistulian time-frame in central Poland. To study it, a multi-proxy approach was applied, involving: palynological and plant macrofossil analysis, study of rounding of quartz grains and morphology of their surface, and investigations of sand mineralogy and till petrography. The results show that a till bed is overlain by a sandy series corresponding to the glacial-interglacial transition. Either one or two distinct peaks of organic accumulation are evidenced by peat horizons. The lower horizon records spectra with hazel and hornbeam, and did, therefore, accumulate in the Eemian. Observed only in some boreholes, the upper peat horizon marks the Brørup (or the lower part of the Rederstall stadial) represented by forest-steppe conditions with patchy mosaics of larch and further transition into sedges and herbaceous taxa. Localized in between the two peat sequences, the sandy horizon marks a long-lasting aeolian transformation with weathering by frost in the Early Vistulian. Again, significant changes of the palaeoenvironmental regime occurred, and are manifested in the one or two horizons of the glaciolacustrine sediments. This corresponded to the last glaciation in the region, when the ice-dammed lakes formed during the Main Stadial

Quaternary stratigraphy and palaeogeography of Poland

Though the stratigraphical and palaeogeographical framework of the Quaternary in Poland is still to be completed, several crucial points have been confirmed recently. The preglacial series, accepted for years as belonging to the Lower Pleistocene, is undoubtedly of Early Pliocene age, with a huge hiatus above almost until the uppermost Lower Pleistocene. The earliest glaciation in Poland (Nidanian) occurred at about 900 ka BP when the ice sheet reached the mid-southern part of the country. The following Podlasian Interglacial embraced the Brunhes/Matuyama boundary in the middle, in a similar fashion to the corresponding Cromerian Complex in Western Europe. The late Early and early Middle Pleistocene interglacials in Poland comprised 2-3 optima each, whereas every one of the younger interglacials was characterised by a single optimum only. The Late Vistulian ice sheet was most extensive in the western part of Poland (Leszno Phase) whereas the younger Poznań Phase was more extensive in the central and eastern part of the country. This was due to the varied distance from the glaciation center in Scandinavia, making the ice sheet margin reach a terminal position in different times. Palaeoclimatological research in the Tatra Mountains has provided new evidence for the atmospheric circulation over Europe. During cold phases of the Pleistocene in Poland a continental climate extended further westwards, quite the opposite that occurring during warmer intervals