Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl
Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 7

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
PL
W artykule przedstawiono charakterystykę litologiczną osadów budujących wybrane formy glacimarginalne: morenę czołową akumulacyjną (stanowisko Masłowice), powierzchnię wysoczyzny morenowej falistej (stanowisko Ochotnik), przypuszczalną morenę martwego lodu (stanowisko Ludwików), kem (stanowisko Miejskie Pola). Formy pochodzą ze stadiału warty zlodowaceń środkowopolskich, są położone na północnych stokach ostańców mezozoicznych Wyżyny Przedborskiej. Wykonano analizy strukturalne, wybrane analizy teksturalne (uziarnienia i morfoskopowe) oraz oznaczono zawartości CaCO3 w osadach. Wykazano znaczący wpływ elewacji radomszczańskiej na przebieg i mieszany charakter deglacjacji. Wskazano, że formy glacimarginalne cechuje zróżnicowanie litofacjalne i litogenetyczne związane z dużą dynamiką deglacjacji lądolodu warty w brzeżnej części lobu Rawki, Pilicy i Luciąży.
EN
The article presents the lithological characteristics of sediments composing some marginal landforms: accumulated frontal moraine (Masłowice site), moraine plateau (Ochotnik site), alleged dead-ice moraine (Ludwików site) and kame (Miejskie Pola site). The landforms developed during the Warta Stage of the Middle Poland Glaciations and are located on the northern slopes of the remnant Mesozoic hills of the Przedbórz Highland. A structural and textural analysis (grain-size distribution and morphoscopy) was made and the CaCO3 content in the sediment was determined. A significant effect of the Radomsko elevation on the course and the mixed nature of the deglaciation has been proved. The marginal landforms are characterized by lithogical and lithofacies diversity related to the high dynamics of the Wartanian ice-sheet in its frontal part of the Rawka, Pilica and Luciąża Lobe.
EN
The petrographical features of the medium- and coarse-grained gravels (4-10 mm and 20-60 mm, respectively) of weathered and fresh (unweathered) deposits indicate, in combination with so-called indicator and statistical erratics, that two glacial lobes joined in the borderland of the Polish Lowlands and Uplands. Lower Palaeozoic limestones become less frequent in the finer gravel fraction, whereas crystalline rocks and flints become more frequent. The petrographical analysis of the coarser gravel fraction indicates that the ice sheet advanced from the NE to NNW (the Widawka lobe) and from the NE to ENE (the Rawka, Pilica and Luciąża lobes). The source areas of the gravel deposited by the Warthian ice sheet were magmatic and sedimentary areas of both the Baltic and the SE Sweden basins.
3
51%
EN
This report contains short information about the geomorphological field trip in the Gujarat Alluvial Plain. During the field trip the issues of fluvial landform and alluvial deposits of the rivers were discussed: Sabarmathi River, Mahi River, Narmada River and Karjan River. Particular attention was paid to the relief and geological structure of the Gujarat Alluvial Plain, dissected by the valleys of several rivers. The role of tectonics, sea level fluctuations and climate changes and their influence on the course of fluvial, aeolian and sea accumulation in the lower sections of river valleys was emphasized.
EN
This study from the Szczerców field of the Bełchatów open-cast mining complex, central Poland, reveals the local geomorphic and stratigraphic history of the Krasówka river palaeovalley – a major western tributary of the river Widawka. The data are from the western flank of the N-trending palaeovalley and the study combines detailed lithofacies analysis of outcrop sections, sediment petrology, AMS measurements and palynological evidence. Radiocarbon dates are of crucial importance for the reconstruction of the palaeovalley history. The study contributes to a better understanding of the response of the Central European river systems to the Vistulian Pleniglacial conditions. The Vistulian Pleniglacial sedimentation in the study area commenced with the accumulation of the latest Eemian to earliest Weichselian (≥45 ka) deposits by sheetwash processes in a local karstic topographic depression. The Krasówka river then formed to the east and shifted farther eastwards, but later approached twice the study area with a net aggradation prior to 43 ka BP – flooding it with overbank deposits. The river subsequently incised by nearly 20 m around 40 ka BP and began to fill in its valley by aggradation around 35 ka BP, while migrating eastwards and markedly decreasing its flooding capacity from 33 to 24 ka BP. The fluvial system was rejuvenated around 21 ka BP, with some initial erosion, and kept filling its valley by aggradation while flooding the valley flank. The river after filling its valley continued to aggrade, but gradually ran out of vertical accommodation and migrated westwards. The fluvial activity at this stage was increasingly accompanied by aeolian sedimentation. Once the Mid-Weichselian Pleniglacial came to an end around 14.5 ka BP, the Krasówka river had re-incised by nearly 5 m and assumed its present-day altitude in response to the post-glacial regional isostatic rebound of crustal basement.
EN
The paper presents results of petrographic analyses of glacial tills in the western part of the Kleszczów Graben and the attempt of their stratigraphic interpretation. Petrographic coefficients have allowed the identification of five till lithotypes: T1, T2A, T2 and T2B – assigned to the South Polish Complex (Elsterian) and T4 correlated with the Middle Polish Complex (Saalian). The well-expressed tills that represent the South Polish Complex, occur at the bottom of the section. A new till lithotype, T2B, has been distinguished, corresponding to the Kuców Formation. It supplements the Pleistocene lithostratigraphic section of central Poland and corresponds to the Sanian 2 Glaciation. Among the younger tills, the T4 one (Odranian Glaciation) is well developed. The uppermost tills of the Wartanian cold stage have been reduced by glaciofluvial and fluvial erosion. It is, to some extent a consequence of the existence of a depression in this area, called the Szczerców Basin. The paper highlights the interpretational difficulties concerning the rank and the number of ice sheet advances during the Polish and Middle Polish Complexes in central Poland.
EN
The paper presents the results of research into the plant macrofossils found in the tectonic Kleszczów Graben, within Mesopleistocene sandy sediments. A number of samples were collected at eight locations from river sediments containing variously sized fragments of plants, mostly from greenish sands overlying Neogene sediments. The structural characteristics of the sediments show a cyclic record of the formation of point bars, their washing out at supercritical conditions, and their aggradation by fine-grained material during flow waning. Based on lithological and structural studies, it has been demonstrated that the sands accumulated in an environment of a meandering river, whose valley bottom was covered with fairly dense vegetation, inhibiting the influx of mineral material to the floodplain from the surroundings – the valley or glacial plateau slopes. The aim of further analysis was to identify the plant genera of the individual macrofossils (about 40 specimens). The most numerous macrofossils were observed in the middle layers of the profile, within sandy megaripple structures, where mostly fragments of Fraxinus and Acer wood were present. In other layers, several fragments of Pinus and three pieces of Populus wood were identified. Additionally, young stems of dicotyledonous plants and fragments of rhytidome (the outer bark of a tree) were found. The results are discussed in combination with considerations on the deposition of the Czyżów Complex in the Bełchatów outcrop, and on the occurrence of local flora.
EN
The paper presents the results of new studies of Quaternary deposits filling the Kleszczów Graben in the Szczerców outcrop, Bełchatów Lignite Opencast Mine. Sedimentary successions were profiled in the fieldwork. Moreover, the borehole data were studied. Laboratory studies included: grain size analyses, analyses of shape and morphology of quartz grain (morphoscopy), analyses of anisotropy of magnetic susceptibility (AMS), palynological, malacological and ostracodological studies, as well as geochronometric (C14) and geochemical (δ18O/δ16O) measurements. The studies were carried out in 2009–2013 and resulted in discovering of some sedimentary formations as well as arranging geological cross-sections and synthetic lithostratigraphic profile. The following sedimantary formations have been distinguished: Folwark, Kuców, Czyżów, Ławki, Rogowiec, Aleksandrów, Piaski and Widawka, arranged into two structural units: the lower one – deformed, and the upper one – undeformed.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.