Geographia Polonica (1988) vol. 55

Abstract

A reconstruction of the conditions of the cold climate environment during the Late Weichselian is made by means of methods of geomorphology and Quaternary stratigraphy. The geomorphological part deals particularly with landforms and material related to nivation and local glaciation, making use of comparisons with contemporary snow-fields and mini-glaciers in northern Lappland. The two main field localities investigated in NW Scania are the horst ridges Sôderâsen and Kullaberg, where geographical evidence and TL-datings are combined with sedimentological and biostratigraphical studies of lake sediments. The results are used for a tentative reconstruction of palaeoclimate and palaeoenvironment 13 500-10 000 BP based on past vegetation and insect fauna, occurrence of stagnant ice, wind and water erosion, nivation and local glaciation.

Björn E. Berglund, Department of Quaternary Geology. Lund University. Tornav. 13 S- 223 63 Lund. Sweden
Anders Rapp, Department of Physical Geography, Lund University, Sölveg. 13, S— 223 62 Lund, Sweden

Abstract

The absolute dating of the deglaciation in South Sweden has been based on a number of different methods. Among those are ¹⁴C-dates on a) marine molluscs, algae, mammals, and sediments, b) limnic sediments and macrofossils, and c) terréstric macrofossils and mammals. Other methods have been to use varved clay connected with the present or local varve-chronologies added to the l4C-chronology. Correlations between the differently dated regions have therefore appeared to be difficult. A correlation method based only on glacial deposits and striations indicated a time-discrepancy between the differently dated deglaciation ages on the west and east coasts. Recent research on the difference between ¹⁴C-years and varve-years during the Late Weichselian suggests that much of the found differences between differently dated regions can be explained by steadily increasing ^l4C production during the deglaciation of South Sweden. The hitherto available data indicate that the time-scales "meet" sometime between 12 700 and 12 800 BP. During the following millennia the gradually higher ^l4C-activity led to gradually younger radiocarbon dates (relative to varve dates). A partly new, preliminary deglaciation chronology, taking these new data into account, is presented with correlations between the west and east coasts. Differences between regions, regarding deglaciation pattern, are discussed as well as possible glaciodynamic and climatic reasons for these anomalies.

Svante Bjôrck, Department of Quaternary Geology. Lund University, Tornav, 13, S-223 63 Lund, Sweden
Björn E. Berglund, Department of Quaternary Geology. Lund University. Tornav. 13 S- 223 63 Lund. Sweden
Gunnar Digerfeldt, Department of Quaternary Geology. Lund University, Tornav, 13, S-223 63 Lund, Sweden

Abstract

Marine hydroacoustic and stratigraphic studies were carried out on Late Quaternary deposits in the Hand Bay, combined with sampling and 14 C datings of pine stumps and peat deposits, pollen analyses of peat and soil horizons and mapping of the sea-bottom by divers. It shows that major water-level changes of the Baltic have been the most important factor for understanding the occurrence and absence of deposits in the Hano Bay. The most spectacular phases in the history of the area is a "pine-phase" between c. 9700-9300 BP when forest spread to areas which today are situated c. 40 m below sea level and a "peat-phase" between c. 8800-7000 BP when peat accumulated rapidly inside the shore bank of that time in areas which today are situated between —7 and —14 m. These quite dramatic water-level changes caused extensive erosion and resedimentation which have resulted in a stratigraphy characterized by many and long hiatuses. No evidences for recent sedimentation of fine-grained sediments have been found in waters of less than c. 60 m water depth.

Svante Bjôrck, Department of Quaternary Geology. Lund University, Tornav, 13, S-223 63 Lund, Sweden
Benneth Dennegârd, Department of Marine Geology, Box 7064, S-402 32 Göteborg and Department of Geology, University of Göteborg and Chalmers University of Technology, S—412 96 Göteborg, Sweden

Abstract

A stratigraphie section of the Kattegat, from Lâsô, Denmark to Billdal, SW Sweden, has been investigated, using hydroacoustic techniques complemented with bottomsampling. A transition occurs, from a predominating Precambrian bedrock surface in the east to Mesozoic strata in the west. The Djupa Rànnan channel separates these two bedrock provinces. Glacigenic deposition, also the late Weichselian and Holocene sediments, has been influenced by the various bedrock configurations. Gas is widespread in the Holocene sediments, rich in organic content.

Benneth Dennegârd, Department of Marine Geology, Box 7064, S-402 32 Göteborg and Department of Geology, University of Göteborg and Chalmers University of Technology, S—412 96 Göteborg, Sweden
Anders Liljestrand, Marine Survey AB , Box 4082, S-^21 04 Västra Frölunda, Sweden

Abstract

The basic research problem of this study involves presenting morpho-dynamic functions of the Wolin cliffed coast along sandy and till sections. Documentary evidence provided by a ten-year cycle of observations (1977-1986) has been utilized. Analysis of the present morphological development of the cliffed coast in Wolin Island has been based on repeated morphological mapping of cliffs and on the compiled morphological and morphodynamic maps. The present approach is a new methodological proposal for the study of the coastal zone.The action of the storm surge is the main process that operates in the coastal zone. Simultaneously, the cliff becomes shaped under the influence of gravity force, water, wind, snow and frost. The cliff's retreat continuously.The extent of the morphodynamic zones recognized, including those of degradation, transport, transport-degradation and accumulation-degradation as well as zone of dynamic equilibrum, varies throughout a year or over a multi-year period and it is dependent on seasonal variations of weather. The denudative system of the cliffed coast in Wolin Island is characterized throughout the year by four morpho-genetic seasons, i.e. autumn-winter, early spring, summer and summer-autumn. The development of the cliffed coast tends to follow the trend of abrasion equilibrium profile.

Andrzej Kostrzewski [Andrzej.Kostrzewski@twarda.pan.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Twarda 51/55, 00‑818 Warszawa, Poland
Zbigniew Zwoliński, Institute of Geoecology and Geoinformation Adam Mickiewicz University in Poznań Dzięgielowa 27, 61-680 Poznań: Poland

Abstract

An alpine cliff and related to it talus slope* are the most typical features of mountainous areas transformed by glaciers. The development of a young cliff starts at the moment when the inclined rock surface becomes free of ice. Very often such surfaces are very steep, vertical or even overhanging and devoid of weathered material. Weathering processes on rock surfaces produce debris which is transported downslope due to gravitational processes such as falling, sliding and toppling. Principal debris slope units formed below cliffs are differing from each other in terms of grain size composition and sorting. Active and non-active or partially active slope surfaces occur adjacent to each other. They are the diagnostic features of past and contemporary periglacial/cryonival environment. Therefore, talus slope features are good indicators of postglacial evolution. Seven types of cliff-debris slope systems have been distinguished in this paper.

Adam Kotarba [kotarba@zg.pan.krakow.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland

Abstract

A time-scale calibrated in radiocarbon years has allowed the last glacial episode in northern Poland to be ascribed to the interval of ca 22 000-13 200 yr BP and its maximum of approximately 20 000 yr BP. An attempt has also been made to present a map of deglaciation isochrones and to approximate the age of major ice-sheet positions; i.e. the Poznań Phase: 18 400 yr BP, the Chodzież Subphase: 17 200 yr BP and the Pomeranian Phase: 15 200 yr BP. Whilst occupying the main positions, the dynamics of the ice sheet front had varied to a higher degree than it was assumed in the former deglaciation models with special preference for the zonal ice sheet waning model. Evidence has been provided by new studies based on the complex facies analysis of marginal phenomena. It allows construction of more realistic depositional models in order to establish a dynamic tendency (D,) of the ice-sheet front on the basis of depositional efficiency (De) estimation. The procedure by means of which models can be constructed is a new methodological proposal in studying the ice-sheet marginal phenomena produced in low energy conditions.

Stefan Kozarski, Committee of Geographical Sciences, Polish Academy of Sciences

Abstract

Biostratigraphical studies on palaeoenvironmental changes have been carried out on sediments from 12 basins in the central part of Bohuslan, southwestern Sweden.Diatom, pollen and radiocarbon analysis have been applied to reconstruct a shore displacement curve for the region.The palaeoenvironmental changes contemporary with the Pleistocene/Holocene boundary and the Holocene transgression maximum have been of special interest.

Urve Miller, Dtpartrnent of Quaternary Research, University of Stockholm, Odengatan 63, S-113 22 Stockholm, Sweden
Ann-marie Robertsson, Geological Survey of Sweden, Box 670, S—751 28 Uppsala, Sweden

Abstract

The present author points out that only in some large subglacial channels of the Dobrzyń Lakeland there are glacial till horizons indicative of ice-sheet participation in their formation. In subglacial channels cut out subglacially by glacial water, which prevail in the study area, the horizons are likely to occur as fluvioglacial erosional levels. There are fluvioglacial accumulative horizons along subglacial channels where outwash water flowed away, independently of their origin, while kame terraces occur in some of large channels filled up with dead ice. There exist lake terraces in subglacial channels in which there were or still are lakes, whereas fluvial terraces are present in considerably transformed channels. Analysis of these levels reveals the origin of channels and allows establishment of channel evolution stages during the Lateglacial and Holocene.

Niewiarowski Władysław, Institute of Geography, Nicholaus Copernicus University, Fredry 8. 87-100 Toruń, Poland

Abstract

This paper summarizes the results of palaeosecular variation (PSV) studies carried out since 1983 in south Sweden. South Sweden is for a number of reasons considered to be a suitable area for these studies. Different types of sediment, covering different periods almost back to the deglaciation, have been analysed. From the Late Weichselian a repeatable pattern of PSV curves have been established. Sediment, dated both with radiocarbon chronology and varve chronology (absolute years BP), indicate a difference between the two time scales. Further investigations will be carried out to confirm these results. Long core palaeomagnetic analyses of a ca 20 m long Holocene sediment succession have resulted in a preliminary PSV curve from this period. With respect to the documented pattern and age of identified turning points, features from both the east European and west European master curves, as presented by Thompson (1983), are found. The preliminary result from this single profile are promising and further investigations from this site will be carried out in the near future.

Per Sandgren, Department of Quaternary Geology, Lund University, Tornav. 13, S-223 63 Lund, Sweden
Svante Bjôrck, Department of Quaternary Geology. Lund University, Tornav, 13, S-223 63 Lund, Sweden

Abstract

The results of geomorphological mapping of the vicinities of Konin have been verified by sedimentological, stratigraphical, radiometric and geochemical studies. The age of the maximum advance of the Vistulian ice sheet has been estimated as about 20 000 yr BP. The 14 C and TL dating is considered not only in terms of palaeogeography but also as a methodological approach. Geo-chemical analyses of tills differing in age, which occur in the vicinity of Konin, serve as a tool, by means of which the deposits can be described and allow an attempt to be made to use the resulting data for the purpose of relative dating of deposits accumulated directly by the ice sheet.

Anna Stankowska, Quaternary Research Institute, Adam Mickiewicz University. Fredry 10. 61-701 Poznań. Poland
Wojciech Stankowski, Quaternary Research Institute, Adam Mickiewicz University. Fredry 10. 61-701 Poznań. Poland

Abstract

The paleogeographic reconstruction of the periglacial zone during the maximum extent of the last ice sheet is based on various studies of cryogenic phenomena, loess, slope and fluvial forms and deposits as well as paleobotanical and paleozoological records. These data show a very high climatic gradient in N-S transect as well the increasing continentality towards east and great diversity of geoecosystems.

Leszek Starkel [starkel@zg.pan.krakow.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Św. Jana 22, 31-018 Kraków, Poland

Abstract

A review of previous studies on slope erosion in Scandinavia introduces a case study of past and recent slope process intensity on Andoya Island in Northern Norway. The pilot study is based on geomorphological mapping from aerial photographs, field controls and quantifications of sediment storage in slope deposits and investigations of lake sediments. The frequency of past catastrophic events (i.e. debris flow activity) was estimated by dendrochronology and studies of lake sedimentation.

Christer Jonasson, Department of Physical Geography. Uppsala University. PO Box 554. S-751 22 Uppsala. Sweden
Lennart Strömquist, Department of Physical Geography. Uppsala University. PO Box 554. S-751 22 Uppsala. Sweden

Abstract

In the proximal zone of the Wda outwash the occurrence of eight outwash levels associated with the outflow of glacial meltwater from the Pomeranian phase was confirmed. Within the outwash a number of subglacial channels and kettle-holes occurs. Part of these landforms is filled with organic sediments — peat and gyttja up to 15 m in thickness. The oldest sediments from the base of these sediments are of Boiling age — dating ¹⁴ C is 12 170-t 250 yr BP.

Jan Szupryczyński [jan.szupryczynski@geopan.torun.pl], Institute of Geography and Spatial Organization Polish Academy of Sciences, Kopernika 19, 87-100 Toruń, Poland

Abstract

In this paper new sites with Eemian and Vistulian floras at the maximum extent of the last ice sheet near Konin are discussed. They show several climatic changes which can be correlated with some of the stadials and interstadials known from NW Europe, NW and Central Poland, i.e. Amersfoort, Brorup, Odderade, Stare Kurowo, Rudunki, Keller and Oerel.

Kazimierz Tobolski, Quaternary Research Institute, Adam Mickiewicz Universitety, Fredry 10, 61-701 Poznań. Poland