GACR

Ecosystems of the Planet Earth are contaminated by toxic elements, major part of which is usually of anthropogenic origin. Although natural cycle of mercury (Hg) was not affected as much by anthropogenic activities as i.e. cycle of lead, its effects on human health and health condition of ecosystems is incomparable. The environment of the Czech Republic is bearing several loads, which originate in its past industrial processing, similarly to selected areas in Poland or Germany. A complex study of the mercury behavior in forest ecosystems of the Czech Republic is thus needed. The data on accumulation or export of mercury from the ecosystems are also unsatisfactory. Existing data on the mercury content in top horizons of forest soils indicate significant contamination, namely in the central Czech Republic. This biogeochemical study aims to evaluate the mercury concentrations and pools in the compartments of the forest ecosystem.

According to present knowledge, the actually used provisional Boreal and the Tethyan J/K boundaries are heterochronous. All attempts to correlate the boundary J/K beds between the Boreal and the Tethyan realms by biostratigraphic methods failed. The aim of the project is to make a detailed and precise correlation of the J/K boundary interval in the Tethyan and Boreal region on the paleomagnetic (localization of reversed subzones) and geochemical base (included the isotope geochemistry and neutron activated analyses). On several pilot localities in the Tethyan region (e.g. Bosso-Italy, Brodno-Slovakia, Puerto Escaňo-Spain) was already successfully used for correlation the high resolution magnetostratigraphy together with detailed microbiozonation.On the only known J/K boundary section without hiatuses in the Boreal realm - Nordvik peninsula in Russia - was successfully elaborated by high resolution magnetostratigraphy together with ammonite biostratigraphy. The project use the methods of high

A multi-disciplinary study of fluvial, paralic and shallow-marine depositional systems of the Cenomanian age of the Bohemian Cretaceous Basin (BCB), Czech Republic combines methods of sequence stratigraphic analysis based on well-log, core and outcrop data, with paleontological and structural analysis, to obtain a detailed picture of evolution of depositional systems and their geometries in space and time. The geometries of Cenomanian strata deposited during the initial phase of basin evolution provide a direct link to the kinematic behaviour of basement structures - especially the Saxothuringian/Tepla-Barrandian suture and the Elbe Fault Zone during the Cretaceous reactivations - and the possible involvement of eustatic fluctuations of variousfrequencies. The research will focus of assessing the relative roles of tectonics and eustatic sea-level change in creating and filling accommodation in an intracontinental basin. This study will also contribute to better understanding of the mechanisms

The proposed research project is aimed at studying the process of rock fracturing in a regime of controlled speed of deformation and a regime of controlled stress during long-term sample loading. The project's starting point consists in a knowledge concerning stress-strain properties of rocks from the ultradeep Kola borehole, plus experience from a study of the process of rock fracturing by means of the statistical methods analyzing sequences of ultrasonic emission. Envisaged research into rock fracturing will proceed from determination of the mechanism of microcracks. Experiments will last from tens of hours up to first hundreds of hours from the onset of loading until final failure. A comparison of the fracturing of analogues of mantle-derived rocks with those in the upper crust may yield new findings on the impact of paleostress on the rock material's ability to accumulate and release energy during brittle fracturing. In methodological terms, the study of rock deformation will

The project is aimed at taphonomic and palaeoecological studies of echinoderms (echinoids, crinoids, asteroids), sponges and brachiopods, and, to a lesser degree, at some other components of the Late Turonian taphocoenoses of the hemipelagic facies in the Ohře region and the siliciclastic facies in the Jizera region, Bohemian Cretaceous Basin (BCB). The most important studied faunal groups will be also taxonomically evaluated. A crucial locality of the project, the Úpohlavy quarry near Lovosice, is relatively well known regarding the geology and stratigraphy.  The conclusions, together with data on ichnology and ichnofabrics, will largely improve our knowledge of sedimentary environments.  Stratigraphic correlations will be based on inoceramids, cephalopods, foraminifers and palynomorphs. Biostratigraphic value of some irregular echinoids (especially Micraster) commonly used in the west European Cretaceous zonation will be tested for the BCB.

The goal of the proposed project is to analyse the functional morphology and taphonomy of microscopical and macroscopical rests of fossils and their assignment to the basic categories of the trophic web. Such a assignment to individual categories makes possible to reconstruct relations of Lower Cambrian to Middle Ordovician organisms of the Barrandian area. The project will provide a model of relations within the Cambrian to Middle Ordovician ecosystem within six selected assemblages. Planctonic and benthic primary producers of the organic matter served as a basis of the trophic pyramide, which was used by different types of consumers (filtrating echinoderms, hyolithids, brachiopods etc.). Such an analyse coud use the already existing data about frequency of separate taxa and functional morphology existing for some groups of invertebrates (e.g. trilobites, hyolithids, brachiopods, echinoderms).

Next to the classical occurrences in southern Bohemia, western Moravia, northern Austria and Lusatia (Germany), moldavites were found also in the Pliocene sediments in the Cheb Basin. Compared to other localities only a littte is known about the chemicalcomposition of moldavites from this region so far: totally four pieces were analyzed for major elements only using electron microporobe techniques. The aim of the project is to provide as complete as possible chemical characteristics of the moldavites from this region based on more representative sample collection. No trace and minor element determination for the moldavites from the Cheb Basin exists so far - the data proposed to be yielded in the framework of this project will represent the first such determination ever. The detailed chemical composition study will reveal the mutual relationships to Bohemian. Moravian, Lusatian and Austrian moldavites which are not clear at the moment.

Moravian part of the Outer Flysch Carpathians offers an opportunity to study the Cretaceous Oceanic Red Beds (CORB) deposited in different environmental settings. Continuous Bystrá section in the Silesian Unit was chosen as principal section. Detail biostratigraphical research based on foraminifera, dinoflagellata, and nannofossils at the section together with selected methods of sedimentology, petrography, mineralogy, and geochemistry will allow build local stratigraphic standard. The standard willserve as a tool for calibration of marker fossils and correlation with selected CORB sections in the Rača and Bílé Karpaty units as well as inter-regionally. Utilization of the local standard by methods of graphic correlation should provide precise dating of significant events in single sub-basins. As a part of this goal the onset of the CORB in different units will be dated. Correlation of the CORB in single sub-basins and obtained paleoenvironmental data will help to create the paleoceanographic

Multidisciplinary project focused on qualitative/quantitative reconstruction of plant habit and structure of Westphalian peat-forming ecosystems in unusual details based on study of in situ buried fossils excavated from volcanic ash beds in the Late Palaeozoic continental basins of the central and western Bohemia. This spectacular material provides unique data on density of vegetation including the understorey, vertical structure of the plant assemblage, and aut- as well as synecological demands of individual species. It also allows correlation of various plant organs commonly found isolated in clastic sediments without any relationship to their parent plants. Mode of occurrence / preservation and association with other species, in situ spores, morphological and, if preserved, also anatomical details (e.g. chared tissues) will be studied using common and special paleobotanical techniques as well as coal petrology, palynology and plant taphonomy methods. Comparison of dispersed spore spectrum

The Ordovician sedimentary sequences in the St Petersburg Region represent a unique sequence of condensed sedimentation, dominated by bioclastic carbonates of temperate zone. The study of ichnofabric of these sediments can answer the following questions:l, to decipher individual episodes of sedimentation, erosion and diagenetic alterations of the Ordovician rocks in the St. Petersburg Region and in all the Baltica; 2, provided a conspicuous symmetry of ichnotaxa and ichnofabrics occurrences across the individual sedimentary sequences will be demonstrated, both local and global eustatic curves for the Early and Middle Ordovician will be precised; moreover, paradigms on the influence of the sea level to the ichnobabric might be upgraded; 3, previous studies in the area have ascertained intensive deep bioturbation and bioerosion of the strata, which are biostratigraphically equivalent to the Lower Ordovician. Such an intensity of deep bioturbation have not been presumed yet for the Early Ordovician.