Das Neokom in Polen und seine paläogeographische Bedeutung

Zusammenfassung Die geologische Geschichte Nordwest-Polens zur Zeit der unteren Kreide kann in allgemeinen Zügen folgenderma\en dargestellt werden:Gegen Ende des Jura, ungefähr zur Zeit des Münder Mergels, sind hier Bewegungen eingetreten, die das Land teilweise trockengelegt und der Denudation preisgegeben haben. In den durch die Bewegungen gebildeten Senken blieben Lagunen erhalten, deren einige brackisches Wasser führten, während in anderen durch Eindampfung Gipslager abgesetzt wurden. Der Serpulit brachte eine positive Meeresbewegung mit, die sich im Infravalanginian derart verstärkte, da\ sich seine Ablagerungen nicht nur in den alten Senken kontinuierlich auf dem Serpulit abgesetzt, sondern auch auf denudierte, früher gehobene Schollen transgressiv ausgebreitet haben. Die Infravalanginian-See war brackisch und hat in NW-Polen typische Wealdenablagerungen abgesetzt, bei Tomaszów aber, etwas südlicher, ist das Infravalangian zwar litoral, aber rein marin ausgebildet, wobei es viele ähnlichkeit mit dem Infravalangian der Teschener Karpathen aufweist. Die Wealdensee und das karpathische Meer waren durch einen Sund verbunden, der sich über Tomaszów längs dem Polnischen Mittelgebirge gegen die Karpathen hinzog. Im Valanginian erreicht die neokome Transgression ihren Höhepunkt, es werden dunkle Tone mit reicher Hilsfauna abgesetzt; wahrscheinlich hat sich diese Transgression von Ru\land über die Polesje-Schwelle und über das westliche Polen nach Deutschland und weiter bis nach Ost-England erstreckt. Das polnische Becken stand in direkter Verbindung mit dem nordwestdeutschen; es war ebenfalls, obwohl dürftiger, mit dem karpathischen Meere verbunden; gerade hier ist der Weg zu suchen, den die Migrationen der nördlichen Elemente ins alpine Becken eingeschlagen haben. Im oberen Valanginian fängt eine Regression an, die in Zentral-Ru\land einsetzt und zu dessen Trockenlegung und zum Abschlu\ der Verbindung des polnischen Beckens mit dem Osten führt. Mit dem Anfang des Hauterivians macht sich die Regression auch in Polen fühlbar und verursacht die Verflachung des Meeres in Polen sowie den Abbruch der Verbindung mit dem karpathischen Meere, in welchem von nun ab keine nordischen eingewanderten Faunenelemente mehr erscheinen. Im oberen Hauterivian zieht sich das Meer von Polen und NO-Deutschland zurück. Auf dem neuen Lande herrscht mächtige Denudation, deren gröbere Produkte sich als sehr mächtige Flu\- und Seesande anhäufen. Das Landstadium dauert während des ganzen BarrÊme, Apt und eines Teiles des Albians an, bis zum Anfang der gro\en Gault-Transgression, die wieder in die Senken vordringt.     

Conditioning clayey soils with a dispersant agent for Deep Soil Mixing application: laboratory experiments and artificial neural network interpretation

Acta Geotechnica - Plasticity of clays makes Deep Soil Mixing (DSM) problematic due to the tendency of the material to congest the rotating blades, reduce mixing efficiency and remain...     

Effects of an Omnivorous Katydid,Salinity, and Nutrients on a Planthopper-<Emphasis Type="Italic">Spartina</Emphasis> Food Web

Top–down and bottom–up effects interact to structure communities, especially in salt marshes, which contain strong gradients in bottom–up drivers such as salinity and nutrients. How omnivorous consumers respond to variation in prey availability and plant quality is poorly understood. We used a mesocosm experiment to examine how salinity, nutrients, an omnivore (the katydid Orchelimum fidicinium) and an herbivore (the planthopper Prokelisia spp.) interacted to structure a simplified salt marsh food web based on the marsh grass Spartina alterniflora. Bottom–up effects were strong, with both salinity and nutrients decreasing leaf C/N and increasing Prokelisia abundance. Top–down effects on plants were also strong, with both the herbivore and the omnivore affecting S. alterniflora traits and growth, especially when nutrients or salt were added. In contrast, top–down control by Orchelimum of Prokelisia was independent of bottom–up conditions. Orchelimum grew best on a diet containing both Spartina and Prokelisia, and in contrast to a sympatric omnivorous crab, did not shift to an animal-based diet when prey were present, suggesting that it is constrained to consume a mixed diet. These results suggest that the trophic effects of omnivores depend on omnivore behavior, dietary constraints, and ability to suppress lower trophic levels, and that omnivorous katydids may play a previously unrecognized role in salt marsh food webs.     

From Cadomian arc to Ordovician passive margin: geochemical records preserved in metasedimentary successions of the Orlica-Śnieżnik Dome in SW Poland

The chemical composition of metamorphosed siliciclastic rocks in the Orlica-?nie?nik Dome (Bohemian Massif) identifies the main sources for the Neoproterozoic [the M?ynowiec Formation (MF)], Early Cambrian [the Stronie Formation (SF)] and Late Cambrian/Early Ordovician [the Goszów quartzites (GQ)] sediments. The MF developed from erosion of a Cadomian magmatic arc along the northern Gondwana margin. The variegated SF, with supra-subduction affinities, shows chemical characteristics pointing to erosion of the freshly exhumed Cadomian orogen and detritus deposition in the back-arc basin. The very different chemical features of the GQ indicate deposition in a basin sited on a passive continental margin. The explanation proposed for the observed changes in chemical composition involves three main stages: (1) The pre ~540 Ma evolution of an active continental margin and related back-arc basin ceased with the collision and accretion of the magmatic arc to the Gondwana margin; (2) Early Cambrian rift to drift transition (540–500 Ma) and development of a depositional basin filled with detritus derived from remnants of the magmatic arc; (3) Peri-Gondwana break-up leading to the formation of shallow-water passive margin depositional basins filled with quartz-rich detritus resembling Early Ordovician Armorican quartzites known from other parts of the Variscan Belt.     

A RATAN-600 Zenith-Field sky survey. Catalog of radio sources

A catalog of radio sources detected in a deep RATAN-600 survey is presented. The catalog was obtained in the region 0^h ≤ RA_2000.0 ≤ 24^h, Dec_2000.0 = 41°30′42″ ± 2′, at the declination of the bright radio source 3C 84. There were nine sessions of multi-wavelength observations at wavelengths λ = 1–55 cm, and more than 300 daily scans were accumulated at each wavelength. This is the first stage in the reduction of an extensive database accumulated by the Cosmological Gene Project. The RATAN-600 Zenith Field (RZF) catalog was obtained at the central wavelength of 7.6 cm, and contains 437 radio sources, virtually all of which have been identified with NVSS objects. Most of the flux densities for the catalog sources are above the 5σ level. Noise from faint (mainly new) background sources at a level of about 0.8 mJy has been detected. The minimum flux density of the catalog, 2.5 mJy, is comparable to the flux-density linit of the NVSS catalog. The catalog is more than 80% complete for sources with flux densities >3 mJy.     

Deciphering late Devonian–early Carboniferous P–T–t path of mylonitized garnet-mica schists from Prins Karls Forland,Svalbard

Quartz-in-garnet inclusion barometry integrated with trace element thermometry and calculated phase relations is applied to mylonitized schists of the Pinkie unit cropping out on the island of Prins Karls Forland, western part of the Svalbard Archipelago. This approach combines conventional and novel techniques and allows deciphering of the pressure–temperature (P–T) evolution of mylonitic rocks, for which the P–T conditions could not have been easily deciphered using traditional methods. The results obtained suggest that rocks of the Pinkie unit were metamorphosed under amphibolite facies conditions at 8–10 kbar and 560–630°C and mylonitized at ~500 to 550°C and 9–11 kbar. The P–T results are coupled with in-situ Th–U-total Pb monazite dating, which records amphibolite facies metamorphism at c. 359–355 Ma. This is the very first evidence of late Devonian–early Carboniferous metamorphism in Svalbard and it implies that the Ellesmerian Orogeny on Svalbard was associated with metamorphism up to amphibolite facies conditions. Thus, it can be concluded that the Ellesmerian collision between the Franklinian margin of Laurentia and Pearya and Svalbard caused not only commonly accepted brittle deformation and weak greenschist facies metamorphism, but also a burial and deformation of rock complexes at much greater depths at elevated temperatures.     

Binary gas sorption/desorption experiments on a bituminous coal: Simultaneous measurements on sorption kinetics,volumetric strain and acoustic emission

There is still no clear understanding of the specific interactions between coal and gas molecules. In this context sorption–desorption studies of methane and carbon dioxide, both in a single gas environment and gas mixtures, are of fundamental interest. This paper presents the results of unique simultaneous measurements of sorption kinetics, volumetric strain and acoustic emission (AE) on three tetragonal coal samples subjected to sorption of carbon dioxide and methane mixtures. The coal was a high volatile bituminous C coal taken from the Budryk mine in the Upper Silesia Basin, Poland. Three different gas mixtures were used in the sorption tests, with dominant CO₂, with dominant CH₄ and a 50/50 mixture.The experimental set-up was designed specially for this study. It consisted of three individual units working together: (i) a unit for gas sorption experiments using a volumetric method, (ii) an AE apparatus for detecting, recording and analysing AE, and (iii) a strain meter for measuring strains induced in the coal sample by gas sorption/desorption. All measurements were computer aided.The experiments indicated that the coal tested showed preferential sorption of CH₄ at 2.6 MPa pressure and exhibited comparable affinities for CH₄ and CO₂ at higher pressures (4.0 MPa). The results of chromatographic analysis of the gas released on desorption suggested that the desorption of methane from the coal was favoured. The relationship between the volumetric strain and the amount of sorbed gas was found to be non-linear. These results were contrary to common opinions on the coal behaviour. Furthermore, it appeared that the swelling/shrinkage of coal was clearly influenced by the network of fractures. Besides, the AE and strain characteristics suggested common sources of sorption induced AE and strain.The present results may have implications for the sequestration of carbon dioxide in coal seams and enhanced coalbed methane recovery (ECBM).     

Chemometric analysis of <Superscript>137</Superscript>Cs activity and heavy metals distribution in the Tatras’ soil

The goal of the paper was to determine the activity of ¹³⁷Cs and ⁴⁰K radionuclides as well as heavy metals Zn, Cr, Pb in soil samples taken from the Tatra National Park in the south of Poland. The samples were obtained as cores (10 cm in diameter) from the top 10-cm layer of the soil. Each sample was divided into three subsamples (a, b and c), where a was the subsample closest to the surface and c was the deepest one. Activity of the radionuclides was determined by means of gamma spectrometry, while analysis of heavy metals was performed (after microwave digestion) using atomic absorption spectrometry technique. The highest activity of cesium-137 was detected (5112 ± 120 Bq kg^?1) in the “a” layer of the core with the peak concentration of cesium-137 (14,452 ± 278 Bq m^?2) in the whole soil core. The highest detected concentration of heavy metals was: Zn—52.8 ± 4.4 mg kg^?1, Pb—260.1 ± 9.4 mg kg^?1, Cr—52.8 ± 4.4 mg kg^?1, respectively. Cluster analysis and principal component analysis were used to examine the obtained data. Application of statistical analysis tools allowed specifying the interdependencies between the examined variables.