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Number of results: 6
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Abstract

The analyzed ridges posses a varying morphology and dimensions. They are composed of rocky blocks of local origin only. The blocks are chaoticly arranged although a position transversal to a morphologic axis of the ridge predominates. The ridges occur mainly in places where distinct structural loosenings of the mountain massifs are noted, at the foot of fresh slopes. They define the periods when rockfalls were most intensive. The authors found the subslope ridges to be the nival moraines.

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Authors and Affiliations

Andrzej Karczewski
Andrzej Kostrzewski
Leszek Marks
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Abstract

Although the terrestrial marginal zones of some glaciers on Spitsbergen are relatively well described, we are largely ignorant about the morphology of their submarine forefields. Initial reconnaissance of the forefields of the Aavatsmark and Dahl glaciers in the Kaffiøyra region and soundings made in that of the Hans Glacier (southern Spitsbergen ) indicate the occurrence of sea-floor push-moraines which can be as much as 3 m high. Their lateral separation is considered to denote annual recession rates. They appear to result from cyclical annual advances of ice-cliffs during winters when the deposits are risen up at the contact of the ice with the sea-floor. The development of the major forms may be related to surge. There is some evidence that certain elements in the sea-bed morphology date from the Little Ice Age (LIA).

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Authors and Affiliations

Marek Grześ
Michał Król
Ireneusz Sobota
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Abstract

Fluted ground moraine deposits in the forefield zones of the Blomli, Scott and Renard glaciers were investigated. It was found that the fluted moraine crests, especially the stone-rich ones, continue on the glacier front surface as cones or stony belts. The linear ablation forms, partly filled by the supraglacial sediment, are the extensions of the crests formed from the finer material. Thus, the opinion is expressed that the ribs and furrows at the top surface of the ground moraine are the result of the supraglacial material deposition and that they reflect the differentation of the ablation relief of the front surface of the recessing glacier. Till now the fluted relief origin was joined exclusively with the subglacial conditions and such forms were considered as the indicators of the glacier movement direction.

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Authors and Affiliations

Tadeusz Merta
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Abstract

This paper offers a comparison of Muriella decolor specimens from different geographical regions and habitats (limestone caves in Poland and ice denuded areas near the Ecology Glacier, King George Island, South Shetland Islands, West Antarctic). Morphological and cytological variability, ecology and life strategies of M. decolor were studied in fresh samples, and also in cultures grown on agar plates. The complete life cycle, with de − tailed ultrastructural (LM and TEM) analysis are presented. The electron microscopic observations prove that materials identified as M. decolor collected in Poland and the Antarctic have distinct ultrastructural features. These include the chloroplast lamella arrangement, mitochondrial cristae structure and the cell wall thickness.
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Authors and Affiliations

Maria Olech
Joanna Czerwik-Marcinkowska
Andrzej Massalski
Anna Wojciechowska
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Abstract

The Ebbabreen ice−cored moraine area is covered with a sediment layer of up to 2.5 m thick, which mostly consists of massive diamicton. Due to undercutting by lateral streams, debris flow processes have been induced in marginal parts of this moraine. It was recognized that the sedimentology of deposits within the deposition area of debris flows is the effect of: (1) the origin of the sediments, (2) the nature of the debris flow, and (3) post−debris flow reworking. Analysis of debris flow deposits in microscale (thin sections) suggests a common mixing during flow, even though a small amount of parent material kept its original structure. The mixing of sediments during flow leads to them having similar sedimentary characteristics across the deposition area regardless of local conditions ( i.e. slope angle, water content, parent material lithology). After the deposition of sediments that were transported by the debris flow, they were then reworked by a further redeposition process, primarily related to meltwater stream action.
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Authors and Affiliations

Krzysztof Pleskot
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Abstract

The main relief features of glacier marginal zones in the region between the Billefjorden and Austfjorden comprise ice-cored moraines, outwash plains and glacial lakes. Characteristics of various types of ice-morainic ridges are given. This article presents examples of outwash fan relief. The results of palaeogeographical analysis serve as the basis for distinguishing between three principal stages of development of glacier morphology and meltwater outflow in the region between the Billefjorden and Austfjorden.

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Authors and Affiliations

Przemysław Gonera
Leszek Kasprzak

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