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Early Holocene alluvia in the lower Wisłok River valley and their chronostratigraphy in the light of radiocarbon datings and palynological analysis

Superson S., Gębica P., Michczyński A., Kołaczek P., Szczepanek K.

Geochronometria

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2017

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Vol. 44, no. 1

216--225

EN

The paper presents the results of the latest radiocarbon dating and the palynological analyses of organic sediments found in the alluvia of the Wisłok River valley between the towns of Łańcut and Przeworsk. The study conducted in the gravel pit made possible the dating of several alluvial fills of the 7–8 m high Holocene terrace and the 5–6 m high floodplain. The oldest channel alluvia and palaeochannel sediments of the 7–8 m high terrace were dated at 10 100–9300 BP (11 960–10 500 cal BP). According to the anthracological analysis the top cover of clay overbank alluvia, which bears charcoal fragments, was deposited in the Subboreal and/or the Subatlantic Phases. In the sequence of the 5–6 m high floodplain, the bottom fills of palaeochannels, dated at 10 195–9885 cal BP (probability level: 68.2%; GdS-3233: 8900 ± 95 BP ) and 11 095–10 755 cal BP (probability level: 68.2%; GdS-3228: 9575 ± 95 BP), were truncated by erosion and covered by alluvia of palaeomeanders, which were active in the 19th century. Preservation of the erosional bench of the Early Holocene organic sediments indicates the predomination of lateral migration of the river channel during the last 200 years and the formation of wide erosional floodplain that has been aggraded with recent flood alluvia. In the 20th century the floodplain aggradation was simultaneous with the deepening of the Wisłok riverbed.

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Instability of the environment at the end of the Eemian Interglacial as illustrated by the isopollen maps for Poland

Kupryjanowicz M., Granoszewski W., Nalepka D., Pidek I. A., Walanus A., Balwierz Z., Fiłoc M., Kołaczek P., Majecka A., Malkiewicz M., Nita M., Noryśkiewicz B., Winter H.

Geological Quarterly

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2016

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Vol. 60, No. 1

225--237

EN

Many terrestrial pollen profiles from Poland (and a few pollen records from other parts of Central Europe) show the end of the last interglacial (Eemian, MIS 5e) to have been characterized by climatic and environmental instability. This is expressed by a strong, rapid cooling in the middle part of the pine phase ending this interglacial (E7 regional pollen assemblage zone), and then a re-warming at the very end of this phase, immediately before the transition to the glacial conditions of the last glaciation (Vistulian, Weichselian, MIS 5d). We have characterized the regional distribution of these climatic fluctuations in Poland on the basis of isopollen maps prepared for the Eemian Interglacial based on palynological data from 31 Polish pollen profiles. These maps show unequivocally that the intra-interglacial cooling at the end of the Eemian Interglacial was a transregional phenomenon, which was reflected very clearly by a temporary openness of vegetation across the whole of Poland. It was associated with a distinct decrease in pine forest areas and an increase in birch forests and open communities of cold steppe type with a domination of Artemisia. The pronounced climate and environment instability during the last phase of the Eemian Interglacial may be consistent with it being a natural phenomenon, characteristic of transitional stages. Taking into consideration the currently observed global warming, coinciding with a natural cooling trend, the study of such transitional stages is important for understanding the underlying processes of climate change.

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12 millennia of climatic and human induced vegetation changes in the lower san valley near Jarosław (se poland) in the light of Pollen analysis

Kołaczek P.

Studia Quaternaria

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2011

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Vol. 28

25-39

EN

Vegetation changes in the Lower San Valley near Jarosław are reconstructed from the Younger Dryas to the present time on the basis of palynological analysis of the peat core. The pollen profile came from a an old riverbed and was supplemented by radiocarbon datings. The Younger Dryas and early Preboreal vegetation was characterised by a high proportion of forest communities with pine (Pinus sylvestris and P. cembra) and birch (Betula), while patches of open area were dominated by the steppe with Artemisia. Climatic amelioration during the Preboreal chronozone led to the rapid spread of elm (Ulmus), which was probably a dominant taxon on the lowest terraces of the valley. Terrestrialization of the water body existing in the palaeomeaner and the subsequent beginning of peat accumulation caused a deterioration in pollen preservation. Hence, the interpretation of the profile section spanning the period between the Boreal and Subatlantic chronozones was seriously disturbed due to selective corrosion and the overrepresentation of Pinus sylvestris type and Filicales monolete sporomorphs. Between ca. 336 and 1152 AD fluctuations in woodland cover were recorded. Important components in those forests, despite the domination of Pinus sylvestris, were Quercus, Carpinus betulus, Fagus sylvatica and Abies alba. The first pollen grains of cereals (Cerealia type) were found before ca. 1605-1414 BC and may be attributed to the agricultural activity of the Neolithic and/or early Bronze tribes. Periods of strong deforestation caused by humans were probably related to the time when the Tarnobrzeska Group of the Lusatian Culture and the Przeworska Culture were active. The first groups of Slavs did not significantly influence the environment, but the subsequent development of those groups led to more visible deforestation, which was triggered after the establishment of Jarosław in the 11th century AD.

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Record of the meso- and neoholocene palaeoenvironmental changes in the Jesionowa landslide peat bog (Beskid Sądecki MTS. Polish Outer Carpathians)

Margielewski W., Kołaczek P., Michczyński A., Obidowicz A., Pazdur A.

Geochronometria

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2011

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Vol. 38, no. 2

138-154

EN

The paper presents an analysis of depositional sequences of landslide peat bog situated in the depressions developed within the landslide landforms Jesionowa in the Beskid Sądecki Mts. (Outer Carpathians). The peat bog, with depositional sequence 2.80 m long, started to form at the begin-ning of the Atlantic Phase ca. 6390-5910 cal BC. Palynological and lithological analyses as well as several (14) radiocarbon age determinations of different horizons in the sediments enabled the recon-struction of palaeoenvironmental changes during the Meso-and Neoholocene. The increase in climate humidity at the beginning of the Subboreal and Subatlantic Phases was observed as delivery of minerogenic material to the peat bog basin and formation of a mineral horizon and an illuvial level within the peat. The particularly intensive delivery of allochthonous material to the peat bog took place at the beginning of the Subboreal Phase and was the result of both significant humid climate and increased human impact (colonization of the Funnel Beaker Culture) in the landslide area. Similar influence of younger colonisations of landslide area (Przeworsk Culture and, later, Valachian coloni-sation) was also recorded within the deposits of peat bog (illuvial and mineral horizons) in the early Subatlantic Phase. Rejuvenation of the landslide zone and formation of the younger landslide were connected with the increase in climate humidity at the beginning of the Subboreal Phase. The peat bog deposits situated within this younger landslide, which are ca. 1.8 m thick, are significantly con-taminated with mineral material.