GACR

Mercury is considered to be one of the most important pollutants due to its ecotoxicological effects. Elevated Hg contents in the environment are closely related to industrialization of developed countries, which began at the end of the 18th century. Recent studies show that current anthropogenic emissions have exceeded those from the natural sources. Geochemical archives such as peat bogs, tree rings or lake sediments are widely used for reconstruction of historical trends of environmental pollution. Although the environment of the Czech Republic is bearing several loads originating in its past, only few studies have dealt with atmospheric Hg deposition. The proposed project aims to evaluate historical change in Hg deposition recorded in tree rings and bark pockets. Obtained data allows us to observe the magnitude of environmental change resulting mainly from industrial activities and evaluate the present day situation. Moreover it could help us in understanding of Hg biogeochemical cycle in the forest ecosystems.

Prague Basin (PB) has become worldwide known area of Lower Palaeozoic due to extensive palaeontological and biostratigraphical investigations. However, disproportional palaeomagnetic and geochemical research does not permit the interpretation of PB palaeosetting and its development. The proposed project is focused on study of volcanic rocks within the Late Ordovician-Early Devonian sequences of the PB. At first, we intend to biostratigraphically establish ages of volcanic phases and use data on petrology, mineral and whole-rock geochemistry and Nd-Sr-Pb isotopes to constrain the character, petrogenesis and geotectonic setting of volcanites of the PB. At second, we intend to define and build new palaeomagnetic database with additional information of palaeomeridians, palaeolatitudes and of the approximate ages. Finally, by integration of the palaeomagnetic position development and geotectonic setting evolution of volcanites, we will determine the PB palaeosetting and its development; improve the location of peri-Gondwanan terranes and contribute to the Early Palaeozoic palaeogeography.

Aim of this project is to define contents of Ga and Ge and establish the Al/Ga- and Si/Ge-ratios in different types of natural silicate melts (granitoids) representing partial melting and following evolution (fractional crystallization, mixing, reaction with fluid) in different positions in the Earth crust. The contents of Ga and Ge will be studied in whole-rock samples and in major rock-forming minerals - quartz, feldspars, micas, and amphiboles etc. We expect to find differences in the Al/Ga- and Si/Ge-ratios not only between different rock series (differences in pT-conditions of melting and fractionation), but also among individual mineral species )differences in crystal structure). Evolution of Al/Ga- and Si/Ge-ration will be compared with the K/Rb, Zr/Hf, Nb/Ta and Y/Ho of analysed rocks. Model of Ga and Ge behaviour in magmatic process will be developed. Chemical analyses will be performed with quadrupole ICP-MS spectrometer Agilent 7500ce equipped with laser ablation system UP213.

Project envisages to devise, but, before all, to optimise, thin film photovoltaic cells on the principle of donor-acceptor systems with charge-transfer, specifically with organic polymers and inorganic nanoparticles. The synthesis of polymers will be needed with appropriate long wave absorption in 600-800 nm region, and outstanding transport properties and stability, but before all nanomaterials with optimised absorption and transport properties will be needed. According to the results with cooperating foreign laboratories we will concentrate, besides standard polymer derivatives PPV(polyparaphenylene-vinylene) and P3HT (polythiofene), on new types of polysilafluorenes and on the percolation optimized nanostructures (quantum rods, tripods and nets) with ZnO and chalkogenides AIIBVI.The main goal will be to optimise electron devices of radiation by means of the minimization of the loss of photons, successive photoexcited excitons and photogenerated charge carriers. We are aiming at two application areas: sensors for the electromagnetic radiation in a wide spectral range 300 - 1200 nm for the general-purpose applications and photovoltaic cells for low cost applications, aiming at the techniques of stamping and nanoprinting of electronic circuits.

The project is expected to refine information on the early and middle Pliocene (i.e. post-Messinian) stage of mammalian evolution in Central Europe, a transitional period which was of a key importance for rearrangement of the Late Cenozoic faunal dynamics. Two model groups of rodents – Arvicolidae and Muridae, will be analyzed with particular respect to variation patterns in particular local populations, the chronological trends in character variation and the interregional relations with particular focus to possible migrations. The project will include (1) field prospection for new sites, revisions of existing sites including excavations and extensive sampling in recently discovered sites which study is in progress: i.e. Měňany 3, Vitošov, Javoříčko, (2) detailed biometric analysis of all available materials of the model taxa, including, (3) comparisons with populations from the Pliocene sites abroad. The project is scheduled for four years.

Lacustrine sediments and largely also coal seams are sensitive indicators of palaeoenvironmental changes. Lake metabolism is very responsive not only to global climatic and geotectonic changes, but also to local climatic, vegetation, erosional and tectonic changes. These processes are frequently linked by reciprocal feedbacks and resulting system behavior is usually non-linear. Understanding a global climatic influence on a paleolake evolution, and filtering off local controls, requires  multidisciplinary approach. Proposed project is focused on the detailed study of 200 m thick succession of lacustrine Cypris Formation and underlying Antonín Coal Seam in the Sokolov Basin (Miocene), where depositional rhytmicity of several orders were observed. Project has strong multidisciplinary nature integrating sedimentological, cyclostratigraphical, magnetostratigraphical, petrological, petrophysical, geochemical and palaeontological approaches. Aim of the proposed project is paleonvironmental and paleoclimatic reconstruction of the Miocene paleolake and comparison of results with data from other Miocene lakes in Europe. Integrated methodological approach will contribute to our understanding of Miocene climate changes and mechanisms of their record to sedimentary rocks.

Aim of this project is the utilization of the chemical composition of magmatic quartz to better understand the genesis of Variscan granites and rhyolites in the Bohemian Massif.Quartz is the relatively most stable rock-forming mineral during majority of post-magmatic processes. Quartz, its internal texture and chemical composition, provide detail information about pT and chemical evolution of silicic magma. Internal texture of quartz crystals visualised by cathodoluminiscence (CL) and in-situ determination of trace element using laser-ablation ICP MS will be combined with existing data of whole-rock chemistry, accessory mineral assemblage, isotopic geochemistry, and eventual also melt inclusions study to reconstruct evolution of several contrasting types of  Variscan granitoid magma in the Bohemian Massif.Another significance of this project is to support methodological development of a new ICP-MS instrument equipped with laser-ablation, which will be installed at the Institute of Geology AS CR,v.v.i. in autumn 2009. Quartz is the simplest matrix among geological materials and thus represents the optimal target for establishment of methodical procedures in a new laboratory.

A complex and spatially extensive study of lithospheric upper mantle of the Bohemian Massif is based on peridotite xenoliths and their host basalts. Chemical, Pb-Sr-Nd isotopic, and microfabric analyses performed on large suite of samples will show the 3-D or 4-D variation of composition, metasomatic transformation, deformation, and seismic properties of the upper mantle beneath the 500km long zone of Cenozoic neovolcanics. The results will bring basic knowledge on physico-chemical properties of the upper mantle in the Bohemian Massif, which is largely missing. The neovolcanic zone studied includes two tectonic domains with clear differences of their lithospheric structures: the Ohře Rift and the Labe/Odra Zone. The proposed research is expected to shed light on processes which led to quasi-synchronous volcanism in such contrasting regions. The spatial variations of the studied parameters of the basalts and xenoliths can indicate the interference between the Variscan terrane architecture, upper mantle structure/composition and neovolcanism.