Crandallite-rich beds of the Libkovice Member, Most Basin, Czech Republic : climatic extremes or paleogeographic changes at the onset of the Miocene Climatic Optimum?

We describe the occurrence and possible origin of rare beds 1-10cm thick and containing 20-70% of crandallite, a Ca-Al phosphate enriched in Sr and Ba, found within otherwise monotonous clay-rich lacustrine sediments of the Most Basin in the Central-European Neogene Ohře Rift system. The beds were formed at ca. 17.31, 17.06, and 16.88Ma, while the entire suite of monotonous clays of the Libkovice Member was deposited between 17.46 and 16.65Ma. Trace-element and organic geochemistry, Ar-Ar geochronology and C-O-Sr isotope systematics are used to infer their source and processes leading to their formation. The most enigmatic aspect of the formation of the crandallite beds is the removal of a huge amount of phosphorus from its biogenic cycle in the lacustrine system, which was otherwise stable for ca. 0.8My. Formation of detritus-poor crandallite beds could result from some exceptional environmental disruptions that hindered transport of fine clastic material to the basin floor. Silicic volcanic activity in the area of the Pannonian Basin could have triggered this disruption. Crandallite could provide evidence of long-lasting droughts and acidification of the exogenic environment, as they are roughly coeval with the onset of the Miocene Climatic Optimum at ca. 17.0Ma

Application of geochemical analysis in the research of chemical fossils

Biomarkers (also termed chemical fossils) are specific organic compounds in geological samples which are derived from biochemical precursors by reductive or oxidative alteration processes. Chemical structures of biomarkers can be related back to the original compounds and utilized as indicators of biogenic, paleoenvironmental and geochemical processes. Examples of identified biomarkers in several studied coals, sediments, and wood fossils remnants are presented

Organic compounds in hardcoal waste piles studied by GC/MS and Py-GC/MS

GC/MS and Py-GC/MS techniques were used to provide information on set of samples from three waste piles localities in Czech Republic. Substituted and unsubstituted phenantrenes and other polycyclic aromatic hydrocarbons were comprised in sample extracts. The results were correlated with petrographic composition

Neutron Activation Analysis in Urban Geochemistry: Impact of Traffic Intensification after Opening the Blanka Tunnel Complex in Prague

Opening of the Blanka Tunnel Complex (BTC) in Prague, Czech Republic, the longest city tunnel in Europe, significantly increased traffic on a connected main road, the V Holešovičkách street (VHS). To study environmental changes in VHS connected with BTC opening, sampling of road dust and airborne particulate matter in the VHS vicinity started 3 years before BTC opening and continued until BTC pilot operation. The enrichment factors calculated for the collected samples from elemental compositions determined by instrumental neutron activation analysis (INAA) have shown significant enrichment for Se, Sb, Hg, Br, Mo, Zn, As, W, Cr, Ba, and Fe, but not their increase after starting BTC operation. The Principal Component Analysis allowed distinguishing between detrital and anthropogenic, probably traffic related, origin of the elements determined in samples. The study demonstrated a potential of INAA for multielement trace analysis of minute samples (28 elements determined in samples down to 20 μg, with detection limits down to sub-ng level) and its application in urban geochemistry studies

Neutron Activation Analysis in Urban Geochemistry: Impact of Traffic Intensification after Opening the Blanka Tunnel Complex in Prague

Opening of the Blanka Tunnel Complex (BTC) in Prague, Czech Republic, the longest city tunnel in Europe, significantly increased traffic on a connected main road, the V Holešovičkách street (VHS). To study environmental changes in VHS connected with BTC opening, sampling of road dust and airborne particulate matter in the VHS vicinity started 3 years before BTC opening and continued until BTC pilot operation. The enrichment factors calculated for the collected samples from elemental compositions determined by instrumental neutron activation analysis (INAA) have shown significant enrichment for Se, Sb, Hg, Br, Mo, Zn, As, W, Cr, Ba, and Fe, but not their increase after starting BTC operation. The Principal Component Analysis allowed distinguishing between detrital and anthropogenic, probably traffic related, origin of the elements determined in samples. The study demonstrated a potential of INAA for multielement trace analysis of minute samples (28 elements determined in samples down to 20 μg, with detection limits down to sub-ng level) and its application in urban geochemistry studies

Charakterizace Eocénové fosilní pryskyřice z Moravy, Česká republika: Pohled do makromolekulární struktury

Two pieces of studlovite - Eoceneamber from Studlov (SoutheastMoravia, Czech Republic) were investigated. To arrive at a more detailed description, attenuated total reflection Fourier transform infrared spectroscopy, Raman spectroscopy, pyrolysis-gas chromatography/mass spectrometry, and gas chromatography-mass spectrometry were used. Both studlovite samples revealed signs of the same plant source, with higher polymerisation and a higher degree of maturation of the fossilized matter. Despite their close spectral resemblance, they differed in their detailed chemical composition, and in structure. Layering of one of the pieces studied showed how the resin was built and what impact the process had on the chemical composition of the amber. Characterization of the organic matter was completed with an analysis of trace elements in amber samples using scanning electron microscope combined with elemental distribution analysis (SEM/EDAX). The results demonstrated the paleoenvironmental conditions that occurred in the plant during resin exudation following wounding.Byly zkoumány dva kusy Študlovského jantaru - Eocénová jantar ze Študlova (jihovýchodní Morava, Česká republika). K získání podrobnějšího popisu byly použity ATR-FTIR, Ramanova spektroskopie, pyrolyzní plynová chromatografie/hmotnostní spektrometrie a plynová chromatografie s hmotnostní spektrometrií. Oba vzorky z oblasti Študlov odhalily známky stejného rostlinného zdroje, s vyšší polymerací a vyšším stupněm zrání fosilních látek. Přes jejich blízkou spektrální podobnost se při detailnějším pohledu na chemické složení a strukturu lišily. Vrstvení jednoho ze studovaných kusů ukázalo, jak byla pryskyřice vytvořena a jaký dopad měl tento proces na chemické složení jantaru. Charakterizace organické hmoty byla dokončena analýzou stopových prvků v jantarových vzorcích pomocí skenovacího elektronového mikroskopu kombinovaného s analýzou elementárních distribucí (SEM / EDAX). Výsledky prokázaly paleoenvironmentální podmínky, ke kterým došlo v rostlině během uvolňování pryskyřice