Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 5
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

The article presents the stages of development of the alluvial fan of the Stryi River (tributary of the Dniester River), which is the largest alluvial cone in the foreland of the Eastern Carpathians. The alluvial fan has a diverse morphology and complex structure, and its formation is the result of the accumulation and erosion activity of several rivers. In order to reconstruct the evolution of the alluvial fan, geological cross-sections of the Stryi, Svicha and Dniester river valleys were made on the basis of archival drillings and field research. The stratigraphy of the alluvial fills is based mainly on morphological (morphostratigraphic) criteria and the correlation of terrace levels with those of adjacent areas. Fluvial sediments from the Late Glacial and Holocene were dated by the radiocarbon method, which allowed the determination of the age of fan dissection. The main factor controlling the course of accumulation and erosion on the alluvial fan was climate change. The accumulation of alluvial covers was preceded by phases of erosion, which generally fell at the end of the glacial periods (late glacial) and the beginning of the interglacials. Differences in the depth of dissection of the strath and the thickness of the accumulated alluvial sediments in the northern and southern parts of the fan may be the result of different tectonic movements and/or the transport capacity and size of river discharges. In the Late Glacial (Alleröd-Younger Dryas) and the Early Holocene the alluvial fan was dissected to a depth of 10–15 m due to the erosion of the Stryi and Dniester rivers.
Go to article

Authors and Affiliations

Andrij Yatcyshyn
1
Piotr Gębica
2

  1. Department of Geomorphology, Ivan Franko Lviv National University, Dorohsenka 41, 79000 Lviv, Ukraine
  2. Institute of Archaeology, University of Rzeszów, Moniuszki 10, 35-015 Rzeszów, Poland
Download PDF Download RIS Download Bibtex

Abstract

The paleoecological research of biogenie sediments sampled in the different lake-mire ecosystems of the ŁęcznaWłodawa Lake District were the basis of studies on hydrological changes during the Late Glacial and Holocene. The lithological differentiation (spatial and temporal) of lacustrine and mire sediments in the studied sites indicates that the hydrological changes were of local nature. The investigations also evidence a specific functioning of the lakes in this region. Lake basins were formed as a result of the ground ice degradation and the transformation of groundwater circulation in the Late Glacial. The total area of lakes in the Lake District was the largest from the Younger Dryas to the Subboreal chronozone. The gradual lowering ofwater level during the early Holocene resulted in the transformation of sedimentation process, and in the development of typologically differentiated mires and lacustrinc-mire complexes
Go to article

Authors and Affiliations

Krystyna Bałaga
Download PDF Download RIS Download Bibtex

Abstract

This paper presents results of investigation on peat and lacustrine sediments from the Kładkowe Bagno peat-bog located in the Puszcza Knyszyńska Forest. Using analysis of plant remains from sediment samples, vegetative and generative finds were identified which allowed describing peat units. Basing on these results, reconstruction of subfossil vegetation and palaeoenvironmental changes in the mire was made. Altogether 4 subassociations of Sphagnetum magellanici were described, which delivered information about humidity of the mire surface during peat forming processes. Stages of deposit development were dated by radiocarbon method. Accumulation of the oldest sediments in the southern basin took place in the Late Glacial. Peat of the northern basin started to accumulate in the Atlantic period. The both parts of the mire aggregated probably 400 years ago.

Go to article

Authors and Affiliations

Danuta Drzymulska
Download PDF Download RIS Download Bibtex

Abstract

Białowieża in Poland is a very famous region in Europe (because of its primeval forest and bison population), but its environmental history is poorly known. This article shows the results of palynological analysis, macrofossil analysis and geological settings of two mires in the Białowieża Forest. The pollen diagrams show changes of the vegetation cover from the younger part of the Late Glacial until the present time. The relative time scale is based on palynostratigraphy and comparison to published results of other sites from the adjacent regions. During the Late Glacial two stages of the vegetation succession were revealed: steppe and forest during the Alleröd period and tundra-like vegetation during the Younger Dryas. The Holocene history consists of five stages of plant cover development. The special features of the Białowieża Forest are conditioned by two main factors: low degree of anthropogenic impact and influences of continental climate and boreal zone, stronger than in the other regions of Poland.

Go to article

Authors and Affiliations

Krystyna Milecka
Agnieszka M. Noryśkiewicz
Grzegorz Kowalewski
Download PDF Download RIS Download Bibtex

Abstract

Vegetation changes in the Lower San Valley near Jaroslaw 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 Jaroslaw in the 11 th century AD.

Go to article

Authors and Affiliations

Piotr Kołaczek

This page uses 'cookies'. Learn more