Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 10

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  Quaternary deposits
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
EN
The manuscript presents fossil records of Riccia spores in the Quaternary deposits. They are rarely reported and identified to the species level during routine pollen analysis. In the available sequences 5 species, including R. cavernosa, R. beyrichiana, R. sorocarpa, R. crinita and R. bifurca were noted. The occurrence of spores in fossil records proves the existence of temporary wet habitats characteristic both for natural environments (e.g. temporary dry lake shores or peat bogs) as well as habitats resulting from human activity, e.g. microhabitats in crops and pastures or trench walls. The spores recorded in sequences present an opportunity for discussion of their potential use as proxies in palaeoenvironmental reconstructions.
EN
The paper presents characteristics of the Pleistocene sediments in the western part of the Holy Cross Mountains. They are subdivided into four complexes and their stratigraphic setting is referred to the updated scheme for the Pleistocene of Poland. The Preglacial Complex includes fluvial sediments characteristic for its lack of Scandinavian material. Sediments of three main glaciations (Nidanian, Sanian 1 and Sanian 2) within the South Polish Complex, are referred also as the South Polish Glaciations. The oldest of these glaciations (Nidanian) is separated from the middle glaciation (Sanian 1) by sediments of the Podlasian Interglacial, represented by clay at the Kozi Grzbiet Cave that contains faunal remains and record of the Brunhes/Matuyama palaeomagnetic boundary. During the middle (Sanian 1) and youngest glaciation (Sanian 2), the Holy Cross Mountains were almost completely covered by the Scandinavian ice sheet, forming glacial deposits separated by fluvial series of the Ferdynandovian Interglacial. The Middle Polish Complex begins with sediments of the Mazovian Interglacial, represented by a pollen record from the Zakrucze site. They are followed by deposits of periglacial and fluvial origin of the Liwiecian Glaciation, Zbójnian Interglacial, Krznanian Glaciation and Lublinian Interglacial. The following glaciation (Odranian) is represented by the youngest glacial deposits that document presence of the Scandinavian ice-sheet in the westernmost part of the Holy Cross Mountains. The North Polish Complex is composed of a climatic warming (Eemian Interglacial) and cooling (Vistulian Glaciation), and is represented by valley and periglacial deposits. The last cooling of the Pleistocene is recorded in faunal remains in the Raj Cave.
EN
In order to better constrain the hydrogeological conditions to the depth of 50 m in the area of water extraction for Wroclaw city, a multi-faceted geophysical survey has been applied. We have combined electrical resistivity tomography (ERT), ground penetrating radar (GPR) and magnetic resonance sounding (MRS) techniques. The results of geophysical investigations indicate the presence of three rock layers with different permeability. The first layer, up to 2 m below ground surface, represents a discontinuous horizon composed of impermeable rocks. The next one, a porous and permeable stratum (aquifer) with a thickness of approx. 5-10 m, comprises saturated sands and gravels. The observed aquifer is characterized by good hydrogeological parameters, wherein hydraulic conductivity (k) equals 5 X 10-4 m/s and porosity reaches 23%. The third layer, below 10 m, is composed of loamy impermeable sediments intercalated with moraine till. At greater depths (>20 m) they are still loamy rocks, but occurring with interbeds of sands (sandy loam). This is confirmed by the hydraulic conductivity in the order of 10-6 m/s, which is typicalfor semi-permeable rocks. Noteworthy, no additional aquifers have been observed to the depth of 50 m.
EN
The risk of dangerous radon emissions in Estonia is high, being among the highest in Europe. In almost 33 per cent of Estonian land area, the content of radon in soil-contained air exceeds the safe limit for unrestricted construction (50 kBq/m3). In such high radon-risk areas the concentration of radon in soil-contained air ranges from 50 to 400 kBq/m3, in a few cases reaching up to 2,100 kBq/m3 exceeding the permitted level for residential areas. The situation is particularly serious in the northernmost part of the country, where uranium-rich graptolite argillite (Dictyonema shale) and the Obolus phosphorite are close to ground surface and their particles are constituent parts of Quaternary deposits. Radon emissions from bedrock have been investigated in detail, but to date Quaternary strata as a source of radon emissions are poorly studied. According to our measurements the highest concentrations of radon are related to tills containing clasts and fines of graptolite argillite and phosphorite. Glacial deposits include also granitoidal material, containing U, Th and K, which have been transported by glaciers from the outcrop areas of crystalline basement rocks in Finland and the Gulf of Finland. Due to weathering, outwash and repeated redeposition other genetic types are poorer in radioactive elements and they are weaker sources of radon.
EN
The investigated area is located in the middle section of the Warta River valley, where the Neogen deposits with lignite series occur within the Adamów tectonic graben. In the Kozmin-North excavation, opened for extraction in 2008 and belonging to the "Adamów"Lignite Mine, the Neogene deposits are covered with an about 30-m thick Quaternary series. The research was carried out to identify the origin and age of the Quaternary sediments. As a result, four sandy series and three till series were identified, which were deposited during the South Polish Glaciations and Middle Polish Glaciations. North Polish Glaciations sediments developed in extraglacial conditions.
EN
The composition of the transparent heavy-mineral assemblages (0.25-0.1 mm) in Quaternary slope, karst, glacial, fluvioglacial and fluvial deposits with different parent material was investigated in the Kielce-Łagów Valley (the central part of the Palaeozoic core of the Holy Cross Mountains). For the purpose, 93 samples of mostly sandy sediments were examined. Some marker and some supporting minerals can be distinguished. Slope and karst deposits are dominated by the abrasion-resistant minerals zircon, tourmaline, staurolite and rutile. This assemblage points at a source consisting of strongly weathered pre-Quaternary bedrock. Glacial and fluvioglacial deposits are dominated by medium-resistant and non-resistant minerals (garnet, amphibole, pyroxene and biotite). The two types of parent material of the heavy minerals are typical of the Quaternary deposits in the Polish uplands. The two sources are most clear in the younger (Vistulian and Holocene), mostly fluvial sediments. The results of the analysis imply that the impact of Pleistocene glaciers on the central part of the Holy Cross Mountains was neither large enough to hide the local mineralogical background, nor sufficient to dominate over the main processes transforming the mineral composition under the variable climatic conditions of the Quaternary, including aeolian processes and chemical weathering.
EN
The investigated area is located along the Noteć Middle Valley and is situated on the border of several physical-geographical and geomorphologic units. There are according to Krygowski (2000): the Noteć Middle Valley, the Gwda Valley, the Wałcz Lake District, the Kraina Lake District, the Chodzież Lake District. Varied geological structure and the relief of the area. The expression of dynamic activity of the last Scandinavian ice sheet are impressive ladforms like end moraine hills of the Chodzież subphase, the Wyrzysk oscillation, glacial gully, outwash levels.
EN
Several possibilities to present and to interpret the results of granulometric analyses of Quaternary fluvial, aeolian, glacial and wash-out slope deposits were investigated. Attention is paid particularly to the cumulative curves at a probability scale and the frequency curves, and it is shown how these curves can help to determine the sedimentary environment. The inclination of the cumulative curves in the part of the maximum proportion of a particular grain size appears significant. It appears possible to obtain information on the density and dynamics of the transporting medium from the course of the cumulative curves (inclination and spread of grain size). The examination of textural parameters allows to draw regression lines characteristic of both deposits from various sedimentary environments and deposits from one single environment but with different histories as to their transport dynamics.
EN
The Ground Penetrating Radar (GPR) measurements presented in this paper had two main objectives. The first was to analize the possibility of using GPR method in examination of sediments in a mountainous geological environment and the second objective was to assess the special distribution of post-glacial sediments and their thickness at a selected site. The experimental measurements were carried out on in the alp of Ornak in the western part of Tatra Mountains This article provides a brief theoretical analysis of possible use of the georadar method in post-glacial sediment examination. The results of GPR surveys done in the reflection profiling mode enable the distinction of zones with different amount of till, clay, sand, gravel and rock debris in the post-glacial sediments.
PL
Badania GPR prezentowane w artykule miały dwa cele: pierwszym było określenie możliwości zastosowania metody GPR do badania utworów osadowych w górskich warunkach geologicznych, a drugim - określenie przestrzennego rozkładu i miąższości utworów postglacjalnych w wybranym miejscu w górach. Badania eksperymentalne przeprowadzono na hali Ornak we wschodniej części Tatr. W artykule zamieszczono krótką dyskusję teoretyczną na temat możliwości zastosowania metody georadarowej do badania osadów postglacjalnych. Zaprezentowane w artykule wyniki badań GPR wykonanych w technice refleksyjnej pozwoliły na wyróżnienie w osadach postglacjalnych stref z różnym nagromadzeniem glin, piasków, żwirów oraz odłamków skalnych.
10
Content available remote Główne przezroczyste minerały ciężkie w osadach czwartorzędowych Polski
PL
W pracy zaprezentowano skład przezroczystych minerałów ciężkich znajdujących się w czwartorzędowych osadach spoistych (gliny zwałowe, mułki, lessy) oraz osadach sypkich (fluwioglacjalnych, rzecznych, wydmowych). Podano propozycję wykorzystania tła spektrum mineralnego mogącego stanowić poziom odniesienia w trakcie prowadzenia szczegółowych badań problemowych.
EN
The paper is focused on the composition of transparent heavy minerals in both cohesive (glacial tills, muds and loesses) and non-cohesive (glaciofluvial, riverine and dune in origin) Quaternary deposits. The proposal is given how to use the background of mineral spectrum that can be a reference level while carrying out detailed problem research.
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.