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Orientation and rounding of limestone coarse grains (5-20 cm) were analyzed in 4 cross sectionts of the middle part of the Wadi Gabes in SE Tunisia. The measured grains were found in the channel floor and banks. It was found that there is an increase in rounding of all measured fractions along the researched part of the wadi. Rounding of fraction 7-10 cm increased the most. Orientation of elongated pebbles were differentiated according to their size. Small pebbles (5-7 cm) were oriented chaotically. Largest pebbles were usually oriented transverse to the wadi channel, which is a result of the rapid deposition from the transportation phase. In the stream current zone apart prevailing transverse orientation the same coarse grains (10-30%) were also imbricated. Orientation and rounding of coarse grains can be used in reconstruction of episodic channels dynamics. Size of the grains that were best rounded and oriented mostly transverse indicate a minimal fraction transported by traction and only sporadically transported in saltation.
The dating and lithological features of the analysed gully fan sediments allow to determine of 4 stages of gully erosion. Based on thickness of the sediments and their age, the rate of accumulation can be calculated. Based on the Visher's granulometric curves and relations between sedimentological indexes were established source of gully erosion products. The stages of gully erosion were compared with archaeological and palynological data. The first stage (from 1500 BC to 3rd century AD) of the development of the gullies was probably determined by climatic factors, because erosion began at the bottoms of the dellies before forest clearance. In this period, the oldest sediments of alluvium type were deposited. The analysis of the values of mean grain size and d-5%, allowed to identify the source and mechanism of sediments transport. The first of gully erosion stage in the studied area was triggered by natural climatic changes linked to the humid periods of the late Holocene. The next stages are linked to both human and climatic influences.
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Stefan Zbigniew Różycki

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Stefan Zbigniew Różycki, geologist, geographer, and traveller, was born on 8 January 1906, in Konstantynówka, near Donetsk. He spent his childhood and early adolescence in Ukraine and later he continued education in gymnasiums in Warsaw and in Częstochowa. After obtaining his school-leaving certificate in 1925 he began geologic and geographic studies at the Faculty of Philosophy of the University of Warsaw. In 1931 he obtained the title of a Doctor of Philosophy in geology and physical geography on the basis of his thesis The Żoliborz 's Interglacial. In 1934 he participated in the Polish expedition to Spitsbergen. In 1939 he took part in the Battle of Modlin Fortress and during the occupation period he engaged in conspiratiorial activities in the Geographic Service at the Supreme Command of the Home Army (AK): he devised military maps, together with a group of architects he prepared the future plans of Warsaw development, and he participated in securement of the scientific geologic collection. After the war (1945-1946) he ran the Study of Town-planning Physiography at the Capital City Reconstruction Bureau. In 1945 he obtained habilitation at the Faculty of Mathematics and Natural Sciences of the University of Warsaw on the basis of his dissertation The Bathonian, Callovian, and Oxfordian stage of the Kraków-Częstochowa Jurassic Highland Chain. He was the first post-war Director of the Department of Geography. In 1946 he was promoted an associated professor and until 1951 he was the Director of the Section of Physical Geography. In 1948- 1951 he was also a Deputy Dean and in 1949- 1950 an Associated Dean of the Faculty of Mathematics and Natural Sciences. In 1951 the Council of Ministers assigned him to organize the Faculty of Geology at the University of Warsaw, and after that, in 1952, he brought into existence the Section of the Quaternary Period Geology (the first in the world) which he ran until 1968. In 1953-1954 he was the Director of the Institute of Geology at the Geological Survey. In 1954 he was promoted for a full professor and since that year he ran the Quaternary Geology Study at the Polish Academy of Sciences. In 1955- 1959 he presided the Expedition Commission in the framework of the International Geophysical Year. He was both the organizer and a participant of many Polish scientific expeditions, among others to Spitsbergen (1958), to Vietnam and China (1956, 1965), to Antarctica (1958/1959), to India (1967), and to Sahara (1970). He was the editor-in-chief of the periodicals „Quaternary Studies in Poland” and „Studia Geologica Polonica”. He was a member of many Polish and many foreign scientific organizations and associations: among others he was a full member of the Polish Academy of Sciences, the first President and a Honorary President of the Committee on Quaternary Studies, a honorary member of the Committee on Polar Research, of the Polish Geologic Society, of the Polish Geographic Society, and of the International Union for Quaternary Research (INQUA). He was also the President of the Polish Scientific Film Association. As a geologist he made a contribution to the Jurassic and Cretaceous deposits research; he is acknowledged to be the creator of the Polish school of the quaternary geology. In the field of geography he contributed mostly as a geomorphologist and a polar explorer. He tutored nearly 200 master's thesis and 26 doctor's dissertations and was the author of over 250 papers and many archival studies. For his scientific, didactic, and organizational output he was honoured with, among others, the National Award of I and II degree, the Commander's Cross with Star Polonia Restituta, the Nicolaus Copernicus Medal of the Polish Academy of Sciences. Stefan Zbigniew Różycki died on 16 September 1988, in Warsaw.
The gullies in the Suwałki Lakeland are located very unevenly. The density of gully network is 0.2 km/km² on average and locally reaches 0,5- 1, 2 km/km². The incisions are located on slopes of tunnel valleys and wide depressions, particularly in the vicinity of met-outs and lakes. These slopes have heights of over 30 m and lengths of over 100 m and are composed of sandy and gravel, sandy silt and sandy till diamictons. The gullies are mostly simple landforms and only sporadically create small dendritic systems. Considering morphology and size of the incisions, two kinds of gullies can be distinguished. The larger gullies are developed along dellies (bowl-shaped, dry valleys) or melt-out valleys. The smaller and shorter gullies occur on the slopes of melt-out depressions and tunnel valleys. Ages of peat covered by fans at the mouths of larger gullies indicate that gully erosion started between 3520±70 to 2240± 100 BP. Two different units build the fans and infilled the gullies. The older unit contains sand and gravel that originated from the bottom and bank erosion of the gullies and resembles alluvium. The younger unit consists of colluvium. The fans at the mouths of smaller and shorter gullies are mainly built of colluvium. The analysed sediments have different characteristics, which indicate that the source material and depositional changes are linked to forest clearance and farmland expansion starting in the 7th century AD and continuing in the Middle Ages.
Research on soil erosion undertaken on selected slopes of the Suwałki Lakeland (NE Poland) in years 1986–1989, 1998–1999 and in 2007 allowed to determine features of deposits transported and deposited within the slopes. Sedimentological analyses were used and following granulometric indices calculated: mean grain size diameter, sorting and skewness. Organic matter content was also determined by loss on ignition. Size of mineral grains (Mz and d-5%) were analysed in relation to rainfall erosivity. Analyses of sediments originated from soil erosion supports previous fi ndings regarding their structural and textural features. Granulometric composition of deluvial deposits is determined by the source material – soil cover. Analysed slope deposits were medium and weakly sorted and their skewness was positive which shows similarity to the slope soil cover. Deposits originated from rill erosion had skewness varying from slightly positive to slightly negative. Rainfall erosivity weakly correlates with the size of mineral grains transported and deposited. This is explained by the fact that transported material included not only separate grains but also grain aggregates and because the material partially originated from rainsplash. Following juxtaposition of sedimentological indices: Mz-σ1, Mz-Sk1, Sk1-σ1 and also Mz with loss on ignition proved helpful in determining conditions of the erosion-transportdeposition process. Multimodal frequency curves with a low amplitude of the modes are characteristic and typical for deluvial sediment. It is found that the minimum transport distance needed for registration of the process in sedimentological properties of the deposits is 30 m. Moreover, only rainfall of a high intensity was able to modify sedimentological proporties of the deposits.
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Z genezy stożków kemowych

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In North-East Poland, in the Riss Glaciation zone there occur hills of a characteristic conical shape. They have asymmetric slopes: one is usually short and steep, the opposite is longer and softer. They are connected with depressions left by blocks of dead ice and usually situated on the border of such basins. They are built of fluvioglacial deposits, sometimes with added ablation clays. They are formed through the accumulation of deposits into cones in large fissures of ice slopes. Their genesis is shown by their inner structure. All the layers originate in the culmination of the cone and thin out in accordance with the longer slope; the measurements of their dip direction indicate a fanshaped disposition of the directions of transport. By way of example two such forms have been described; they are situated in the western part of the Białystok Upland and in the North-East part of the Wysokie Mazowieckie Upland. Because of their morphometric and structural features they are called came cones (R. F. Flint 1957, A. Karczewski 1971, A. Musiał, K. Straszewska, M. Ziembińska-Tworzydło 1982, A. Musiał 1983).
The aim of studies was the recognition of the contemporary denudation considering tillage translocation and water soil erosion. This study was performed in the typical last glacial relief. The Cs-137 inventory was analysed along two hillslope profiles and at their footslopes. The value of soil erosion and sedimentation was calculated using the proportional model and the simplified mass balance model. Studies showed that eroded soil from upper and middle segments of the slopes was re-deposited on concave segments of the slopes. The erosion rate was 0.5-1.6 mm on the top of hills and 0.8-3.2 mm on their slopes. The deposition occurs on the concave slope at rate of 3.8-6.6 mm per year on average. Erosion-deposition balance indicate that the small part of eroded soil was exported to the valley bottom and bottom of depression. The share of the water rill and interrill erosion in the total of topsoil erosion is range from 1 to 10% depending on used model. Tillage translocation is the main process shaped a small hills in the last glacial ares.
The aim of the study performed in years 2007-2009 in the Suwałki Lakeland was assessed the intensity of soil erosion and runoff on a sandy slope under different cultivation. The study also focused on analysis of selected factors affecting the erosion (intensity of rainfalls, erosion susceptibility of soil, vegetation cover). Measurements were performed on the standard USLE plots inclined 8°. The mean annual erosion amounted to 0,2 t ha⁻¹ under cereals (rye and oat), 2,1 t ha⁻¹ under potatoes planted in rows parallel to the slope gradient, and 2,75 t ha⁻¹ on the black fallow. Experimentally determined index of erosion susceptibility K was 0,0041. The mean annual value of the canopy factor C was 0,064 for cereals and 0,8 for potatoes. Short rainfall events of 20-30mm and erosivity 100-200 MJ mm ha⁻¹h⁻¹ are characteristic for the study area. The results obtained for the sandy slope support previous findings that such short-term events play a significant role in soil erosion. Effectivity of such events strongly depends on the vegetation cover as they are responsible for 25-30% of soil loss under potatoes and 45-50% under cereals.
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In years 2007-2009 soil erosion measurements were conducted on plots and hillslopes with not separated area. The separated plots were closed by the Gerlach troughs with collectors. Measurements with not separated area were carried with the modified collectors of Słupik (entrance width 0,5 m). The aim of the paper is to compare the results and to evaluate the usefulness of the small collectors. Annual amounts of eroded soil occurred to be 12% smaller for cereals and 26% smaller for potatoes in comparison with erosion recorded in the separated plot. On a convex slope amounts of eroded material were higher (20% on average). On the other hand, the erosion on a concave slope was less effective (c. 35%) during any rainfall conditions. Mass of soil material collected in 10 collectors situated near each other was compared. It is calculated that measurement error due to the collector effectiveness and local differentiation of the geomorphic processes is ±6% if only two neighbouring collectors are considered and up to ±4% if tree catchers are taken into consideration. This error increase up to ±30% during small erosivity rainfalls (El₃₀< 20 MJ mm ha⁻¹h⁻¹).
The aim of the study was the analysis of scructural and texcural features of the slope cover deposits in relation to the character of the substratum deposits. The slope of a small hillock formed of fluvioglacial deposits was chosen as representative of the last glaciation area. Structure of the near-surface parts of the hillock and the slope cover deposits were analysed based on five pies dug along the longitudinal profile. The grain size distribution was established using the sieve method. The granulometric indices were calculated according to the Folk and Ward (1957) formulae. The slope cover deposits are uniform and consist of sand of varied grain size, with share of fine and very fine grains. Thickness the slope cover is of up to 150 cm. At the floor two colluvial mineral series appear, of 30-40 cm thickness, with flow structures and laminated. The main mass of this cover consists of soil colluvia. Within the soil colluvia three humus horizons were distinguished. The lowermost fossil humic horizon, dated at 2740 ±70 BP, points to deposition of material at the slope base mainly as a result of anthropogenic denudation. The overlying humic horizon proved to be older (3160±90 BP), which points to stepwise erosion of successive older slope covers and their redeposition at the hillock base. The slope deposits are finer and worse sorced in comparison to their source deposits. Frequency curves for colluvia from wash are chracterised by higher number of distinguishable modes in comparison with the source material. Over the whole slope length of 75 m a slow sorting occurred. It resulted in the changed relationship becween the main grain diameter and the standard deviation, from type I, representing fluvioglacial deposits, into type II, comprising colluvial deposits. Cumulacive curves of colluvial deposits differ from those of fluvioglacial origin in a weaker separation of populacion corresponding to the kinds of transport and in a narrower inclination angle.
Fluvial and slope deposits were investigated in the NW part of Masovia region. Their deposition was conditioned by anthropopression. There were recognised lithological features and analysed in vertical profiles such characteristics as: grain size, organic matter and selected elements (eg. Zn, Pb, Cu, Cd, Ni, P). Selected samples with organic matter were dated using the radiocarbon method. Age of sediments and their sedimentological and geochemical characteristics let to destinguish the series of deposits correlated with such periods of human activity as: Wielbark and Przeworsk cultures, the Middle Ages, the modern and industrial periods with last 100 years heavily affected by human activity. A very characteristic feature of the study area is a general very small content of analysed elements - close or very near to values of geochemical bacground but it is varied in vertical profiles of both slope sediments and fluvial ones. In the area of Brudzeń Duży the highest concentrations of analysed metals were recorded in the sediments accumulated during the Middle Ages, especially early phases of this period, what corresponds to the economic activity of the Slavs in this area (the two strongholds in Brudzeń Duży and Parzeń). Thereafter it was an agricultural region. In the area of Borowiczki the maximum concentrations occur at the land surface and it is correlated with the human activity of the last 40 years - that is, since the creation and operation of petrochemical plant in Płock. The carried studies indicated that trace elements in sediments, even occuring in small concentrations may be helpful in separating the layers by the age of deposition and in determining the rate of sedimentation at footslopes or in valley bottoms (overbank during the floods).
The article describes morphology and dynamics of 2 small wadis (gullies) in the vicinity of Gabes, tributaries of the Wadi Gabes, which cut a loess cover of sea-side region. Mapping in 1995 and 1998 was aimed to recognize contemporary gullying resulting from precipitation 807 mm with maximal 51 and 92 mm per day. Slope gradients and length of the thalweg as well as depth and width in cross sections were measured. The gullies are characterized by many knickpoints, but only few are up to 1 m. The changes in morphology of the gullies indicate slow retreat of the knickpoints (sporadicaly to 60 m) or their cutting and the incision along most of the gully length (5-10 cm locally more), as well as lateral erosion, particularly in lower parts of the gullies. The deposition occurred only locally and was very irregular. Changes in morphology of the gullies were very limited due to highly calcareous loessial and sandy-gravel bedrock. The length of the gullies increased due to the development of deep rills above heads of the gullies and their sinuosity in the lower part. The rate of gully heads advance is about 1,6 and 2,5m m per year.
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