Geology topics

Research about Czech Republic

Source-linked reports with geographic coverage including Czech Republic.

14 recordsLinked to original sources

USGS2026

Trace element heterogeneity and crystallization history of the Plesovice zircon: Implications for its use as a U–Pb LA-ICP-MS reference material

Zircon crystals from Plešovice hyperpotassic granulite (HPG) have been widely used as a reference material for LA-ICP-MS dating. Detailed cathodoluminescence (CL) imaging and trace element analysis reveal a complex internal structure of Plešovice zircon linked to extreme chemical heterogeneity, which allows us to distinguish different zircon domains formed during its crystallization: (i) rare low-CL cores enriched in U, Nb, HREE and Y; (ii) dominant sector-zoned to oscillatory-zoned domains, and (iii) CL-bright rims poor in trace elements. Relic fine oscillatory zoned areas are chemically homogeneous, whereas coarsened and blurred areas, and CL-dark replacement domains, are heterogeneous. Based on these data we suggest a complex and protracted zircon evolution: (i) crystallization of metamorphic zircon in anatectic calc-alkaline granulite; (ii) magmatic zircon crystallization at high temperature and pressure in a dry ultrapotassic melt at presence of peritectic garnet; (iii) coupled zircon dissolution-precipitation processes triggered by percolating hydrous residual melt; and (iv) coarsening and replacement of the pre-existing zircon due to prolonged exposure to a reactive fluid/hydrous melt. New CA-ID-TIMS U Pb dates between 337.167 ± 0.080 and 337.840 ± 0.080 Ma confirm crystallization age for HPG zircon at around 337.4 Ma and suggest that previously published dates of 336.37 Ma were biased by non-mitigated lead loss. We thus confirm the U/Pb homogeneity of Plešovice reference zircon despite its chemical heterogeneity. We further discuss the implications of using the chemically extremely heterogeneous Plešovice reference zircon as primary or secondary standard for in-situ LA-ICP-MS geochronology, in particular for quantification of the chemical matrix-dependence of the relative sensitivity factor ( β ) of laser ablation.

Plešovice quarry↗

USGS2025

Mercury cycling in the Czech GEOMON network catchments recovering from acid deposition and facing climate change

We used the catchment mass balance approach to investigate mercury (Hg) cycling at the 14 forested GEOMON catchments of the Czech Geological Survey. The temperate forest catchments had variable exposure to historic high sulfur (S) and Hg emissions, and span a range of size and elevation. We monitored monthly Hg inputs (bulk precipitation, throughfall, litterfall) and outputs (stream runoff) during 2020–2022. The catchments spanned a large gradient of historic Hg deposition, but current Hg patterns more closely aligned with catchment factors like local climate, as influenced by elevation, dissolved organic carbon (DOC) concentrations, and geology. The dominant pathway of Hg input was litterfall (averaging 44.5 ± 15.7 µg m −2 yr −1 ; > 91% of total input). Two surprising findings were that GEOMON had low Hg concentrations and fluxes in general but had the highest litterfall Hg fluxes in Europe, and these increased even further in forested areas that had bark beetle infestations. Gaseous elemental mercury (GEM), measured using passive samplers, was consistently low (1.25 to 1.66 ng m −3 ) across the 14 catchments. Stream Hg output varied across catchments and averaged 1.5 ± 1.7 µg m −2 yr −1 . The average Hg retention rate at the 14 GEOMON catchments, calculated as the fraction of average Hg inputs (throughfall + litterfall) that remained in the catchment and did not run off in streamwater, was 97%. The high catchment Hg retention combined with its strong association with DOC suggests that with climate change intensification of carbon cycling, these catchments will be a Hg source for decades to come.

Biogeochemistry↗

USGS2023

Atmospheric mercury and its deposition during the phasing out of an amalgam electrolysis plant: Temporal, seasonal, and spatial patterns

Large amounts of mercury (Hg) were consumed and emitted into the atmosphere during the process of amalgam electrolysis used to produce chlorine and caustic soda since the nineteenth century. In Europe, amalgam electrolysis has been gradually replaced by advanced Hg-free technologies. In this work, we describe changes in atmospheric Hg and bulk Hg wet deposition during the phasing out of an amalgam electrolytic production line of a chlor-alkali plant in Neratovice, Czech Republic, central Europe. Bulk wet deposition Hg near the chlor-alkali plant was low at 3.6 ± 0.8 μg m −2 year −1 due in part to low annual precipitation amounts (486 ± 97 mm) in the period 2015–2021. Nevertheless, Hg deposition was elevated relative to a nearby reference site both before and after decommissioning of the electrolytic line. Switching off the amalgam electrolytic line did not notably affect bulk wet deposition Hg near the chlor-alkali plant. Levels of gaseous elemental Hg (GEM) and particle-bound Hg (PBM) monitored seasonally four times per year over 24-h time periods indicated rapid declines in four nearby settlements set in cardinal directions from the Hg emission source. Mean atmospheric GEM and PBM concentrations decreased rapidly from 9.0 ± 2.1 ng m −3 and 243 ± 255 pg m −3 in the period 2013–2017 when amalgam electrolysis was operating to 3.3 ± 0.4 ng m −3 and 32 ± 6 pg m −3 in the period 2018–2021 after its decommissioning in November 2017. Seasonal changes of GEM coincided with changes in temperature with the highest concentrations in summer, while PBM air levels were lowest in summer due to the highest seasonal precipitation amount. GEM concentrations at the four monitored settlements at Neratovice remained elevated at 2.8 ng m −3 with respect to regional background, but PBM levels decreased to background levels.

Neratovice↗

USGS2021

Mercury cycling during acid rain recovery at the forested Lesní potok catchment, Czech Republic

From 2011 to 2019, mercury (Hg) stores and fluxes were studied in the small forested catchment Lesní potok (LES) in the central Czech Republic using the watershed mass balance approach together with internal measurements. Mean input fluxes of Hg via open bulk deposition, beech throughfall and spruce throughfall during the periodwere 2.9, 3.9 and 7.6 μg m −2 year −1 , respectively. These values were considerably lower than corresponding deposition Hg fluxes reported in the early years of the 21st century from catchments in Germany. Current bulk precipitation inputs at unimpacted Czech mountainous sites were lower than those in Germany. The largest Hg inputs to the catchment were via litterfall, averaging 22.6 and 17.8 μg m −2 year −1 for beech and spruce stands. The average Hg input, based on the sum of mean litterfall and throughfall deposition, was 23.0 μg m −2 year −1 , compared to the estimated Hg output in runoff of 0.5 μg m −2 year −1 , which is low compared to other reported values. Thus, only ~2% of Hg input is exported in stream runoff. Stream water Hg was only weakly related to dissolved organic carbon (DOC) but both concentrations were positively correlated with water temperature. The estimated total soil Hg pool averaged 47.5 mg m −2 , only 4% of which was in the O-horizon. Thus Hg in the O-horizon pool represents 72 years of deposition at the current input flux and 3800 years of export at the current runoff flux. Age-dating by 14 C suggested that organic soil contains Hg from recent deposition, while mineral soil at 40–80 cm depth contained 4400-year old carbon, suggesting the soil had accumulated atmospheric Hg inputs through millennia to reach the highest soil Hg pool of the soil profile. These findings suggest that industrial era intensification of the Hg cycle is superimposed on a slower-paced Hg cycle during most of the Holocene.

Lesní potok↗

USGS2021

Distribution and pools of mercury in forest soils near recent and historical mercury emission sources in the central Czech Republic

The fate of atmospherically deposited mercury (Hg) was studied in forest soils situated near various Hg anthropogenic emission sources, including chlor-alkali plants, cement production, and pig iron and steel factories in the Czech Republic. Some of these emission sources were more active in the past, while others continue operation with lowered dust and Hg emissions up to the present day. The impact of Hg emission sources on forest soil was assessed with respect to other soil parameters, including organic carbon, soil nitrogen, soil sulfur, and soil oxalate-extractable aluminum and iron concentrations. The site-specific mean Hg concentrations in organic horizons (174–479 μg kg −1 ) were greater than mean Hg concentrations in mineral soil (15–88 μg kg −1 ). Site specific mean Hg/C ratios in organic horizons at four study sites ranged from 0.8 to 2.4 μg g −1 , while mean mineral soil Hg/C varied from 2.0 to 3.4 μg g −1 . Near cement plants, an 8- to 30-cm thick layer composed of dust particles was identified below or mixed with current O and A horizon material (Hg concentrations 122 to 401 μg kg −1 ). Mean mineral soil pools of Hg (13–24 mg m −2 ) dominated over the mean organic horizon Hg pools (2–11 mg m −2 ). Near cement plants and steel works, Hg concentrations and pools in organic horizons and mineral soils were within the range reported from pristine Czech forest soils. Elevated Hg concentrations in organic horizons were found near a chlor-alkali plant. Thermal decomposition analysis indicated that Hg in A horizons at all sites and dust horizons near cement plants was bound similarly to Hg in foliage.

Journal of Geochemical Exploration↗

USGS2018

Larch tree rings as a tool for reconstructing 20th century central European atmospheric mercury trends

We propose the tree rings of European Larch ( Larix decidua ) as a widely available and reliable geochemical archive of local and regional changes in atmospheric mercury (Hg). Mean Hg concentrations in larch tree rings from 8 background sites across the Czech Republic ranged from 2.2 to 4.8 μg kg –1 ; the maximum concentrations occurred in the period 1951–1970. At 3 sites impacted by Hg-emission sources [gold amalgamation processing, caustic soda production, and lead (Pb) ore smelting] mean larch tree ring Hg concentrations were significantly elevated relative to background sites. Changes in larch tree ring Hg concentrations were temporally coherent with known activities at the sites that would alter Hg emissions; the nearly simultaneous response in tree rings indicated little or no translocation of Hg within the larch bole. Based on the present-day atmospheric Hg concentration of 1.63 ng m –3 at the intensively monitored Czech Global Mercury Observation System site and the most recent mean tree ring Hg concentration of 2.8 μg kg –1 in co-located larch trees, we developed a simple distribution model of Hg between the atmosphere and larch tree rings. We applied the model using observed changes of Hg in larch tree rings from the countrywide background sites to reconstruct past atmospheric Hg concentrations in central Europe. Modeled Hg concentrations were in agreement with annual means from the European Monitoring and Evaluation Programme observatories.

Environmental Science & Technology↗

USGS2018

Stability of mercury concentration measurements in archived soil and peat samples

Archived soil samples can provide important information on the history of environmental contamination and by comparison with recently collected samples, temporal trends can be inferred. Little previous work has addressed whether mercury (Hg) concentrations in soil samples are stable with long-term storage under standard laboratory conditions. In this study, we have re-analyzed using cold vapor atomic adsorption spectroscopy a set of archived soil samples that ranged from relatively pristine mountainous sites to a polluted site near a non-ferrous metal smelter with a wide range of Hg concentrations (6 - 6485 µg kg-1). Samples included organic and mineral soils and peats with a carbon content that ranged from 0.2 to 47.7%. Soil samples were stored in polyethylene bags or bottles and held in laboratory rooms where temperature was not kept to a constant value. Mercury concentrations in four subsets of samples were originally measured in 2000, 2005, 2006 and 2007, and re-analyzed in 2017, i.e. after 17, 12, 11 and 10 years of storage. Statistical analyses of either separated or lumped data yielded no significant differences between the original and current Hg concentrations. Based on these analyses, we show that archived soil and peat samples can be used to evaluate historical soil mercury contamination.

Chemosphere↗

USGS2017

The history of mercury pollution near the Spolana chlor-alkali plant (Neratovice, Czech Republic) as recorded by Scots pine tree rings and other bioindicators

We assessed > 100 years of mercury (Hg) pollution recorded in the tree rings of Scots Pine near a Czech chlor-alkali plant operating since 1941. Hg concentrations in tree rings increased with the launching of plant operations and decreased when Hg emissions decreased in 1975 due to an upgrade in production technology. Similar to traditional bioindicators of pollution such as pine needles, bark and forest floor humus, Hg concentrations in Scots Pine boles decreased with distance from the plant. Mean Hg in pine bole in the 1940s ranged from 32.5 μg/kg Hg at a distance of 0.5 km from the plant to 5.4 μg/kg at a distance of > 4.7 km, where tree ring Hg was the same as at a reference site, and other bioindicators also suggest that the effect of the plant was no longer discernible. Tree ring Hg concentrations decreased by 8–29 μg/kg since the 1940s at all study sites including the reference site. The lack of exact correspondence between changes at the plant and tree ring Hg indicated some smearing of the signal due to lateral translocation of Hg from sapwood to heartwood. Bole Hg concentrations reflected local and regional atmospheric Hg concentrations, and not Hg wet deposition.

Neratovice↗

USGS2016

Soil mercury distribution in adjacent coniferous and deciduous stands highly impacted by acid rain in the Ore Mountains, Czech Republic

Forests play a primary role in the cycling and storage of mercury (Hg) in terrestrial ecosystems. This study aimed to assess differences in Hg cycling and storage resulting from different vegetation at two adjacent forest stands - beech and spruce. The study site Načetín in the Czech Republic's Black Triangle received high atmospheric loadings of Hg from coal combustion in the second half of the 20th century as documented by peat accumulation rates reaching 100 μg m −2 y −1 . In 2004, the annual litterfall Hg flux was 22.5 μg m −2 y −1 in the beech stand and 14.5 μg m −2 y −1 in the spruce stand. Soil concentrations and pools of Hg had a strong positive relation to soil organic matter and concentrations of soil sulfur (S) and nitrogen (N). O-horizon Hg concentrations ranged from 245 to 495 μg kg −1 and were greater in the spruce stand soil, probably as a result of greater dry Hg deposition. Mineral soil Hg concentrations ranged from 51 to 163 μg kg −1 and were greater in the beech stand soil due to its greater capacity to store organic carbon (C). The Hg/C ratio increased with depth from 0.3 in the O-horizon to 3.8 μg g −1 in the C horizon of spruce soil and from 0.7 to 2.7 μg g −1 in beech soil. The Hg/C ratio was greater at all mineral soil depths in the spruce stand. The organic soil Hg pools in beech and spruce stands (6.4 and 5.7 mg m −2 , respectively) were considerably lower than corresponding mineral soil Hg pools (39.1 and 25.8 mg m −2 ). Despite the important role of S in Hg cycling, differences in soil Hg distribution at both stands could not be attributed to differences in soil sulfur speciation.

Ore Mountains↗

USGS2015

Mercury in stream water at five Czech catchments across a Hg and S deposition gradient

The Czech Republic was heavily industrialized in the second half of the 20th century but the associated emissions of Hg and S from coal burning were significantly reduced since the 1990s. We studied dissolved (filtered) stream water mercury (Hg) and dissolved organic carbon (DOC) concentrations at five catchments with contrasting Hg and S deposition histories in the Bohemian part of the Czech Republic. The median filtered Hg concentrations of stream water samples collected in hydrological years 2012 and 2013 from the five sites varied by an order of magnitude from 1.3 to 18.0 ng L − 1 . The Hg concentrations at individual catchments were strongly correlated with DOC concentrations r from 0.64 to 0.93 and with discharge r from 0.48 to 0.75. Annual export fluxes of filtered Hg from individual catchments ranged from 0.11 to 13.3 μg m − 2 yr − 1 and were highest at sites with the highest DOC export fluxes. However, the amount of Hg exported per unit DOC varied widely; the mean Hg/DOC ratio in stream water at the individual sites ranged from 0.28 to 0.90 ng mg − 1 . The highest stream Hg/DOC ratios occurred at sites Pluhův Bor and Jezeří which both are in the heavily polluted Black Triangle area. Stream Hg/DOC was inversely related to mineral and total soil pool Hg/C across the five sites. We explain this pattern by greater soil Hg retention due to inhibition of soil organic matter decomposition at the sites with low stream Hg/DOC and/or by precipitation of a metacinnabar (HgS) phase. Thus mobilization of Hg into streams from forest soils likely depends on combined effects of organic matter decomposition dynamics and HgS-like phase precipitation, which were both affected by Hg and S deposition histories.

Journal of Geochemical Exploration↗

USGS2011

Cross-borehole flow analysis to characterize fracture connections in the Melechov Granite, Bohemian-Moravian Highland, Czech Republic

Application of the cross-borehole flow method, in which short pumping cycles in one borehole are used to induce time-transient flow in another borehole, demonstrated that a simple hydraulic model can characterize the fracture connections in the bedrock mass between the two boreholes. The analysis determines the properties of fracture connections rather than those of individual fractures intersecting a single borehole; the model contains a limited number of adjustable parameters so that any correlation between measured and simulated flow test data is significant. The test was conducted in two 200-m deep boreholes spaced 21 m apart in the Melechov Granite in the Bohemian-Moravian Highland, Czech Republic. Transient flow was measured at depth stations between the identified transmissive fractures in one of the boreholes during short-term pumping and recovery periods in the other borehole. Simulated flows, based on simple model geometries, closely matched the measured flows. The relative transmissivity and storage of the inferred fracture connections were corroborated by tracer testing. The results demonstrate that it is possible to assess the properties of a fracture flow network despite being restricted to making measurements in boreholes in which a local population of discrete fractures regulates the hydraulic communication with the larger-scale aquifer system.

Bohemian-moravian Highland↗

USGS2006

Factors determining Pochard nest predation along a wetland gradient

Waterfowl management on breeding grounds focuses on improving nest success, but few studies have compared waterfowl nest success and factors affecting nest survival along a wetland gradient and simultaneously identified nest predators. We monitored nests (n = 195) of common pochards ( Aythya ferina ) in Trebon Basin Biosphere Reserve, Czech Republic, during 1999–2002. Daily nest survival rates (DSRs, logistic-exposure) declined from island (0.985, 95% confidence interval, 0.978–0.991) to overwater (0.962, 0.950–0.971) and terrestrial (0.844, 0.759–0.904) nests. The most parsimonious model for DSRs included habitat class (DSRs: island > overwater > terrestrial) and nest visibility. Nest survival was improved by reduced nest visibility, increased water depth, and increased distance from the nest to habitat edge in littoral habitats. On islands, nest success increased with advancing date and increased distance to open water. A model of constant nest survival best explained the data for terrestrial nests. There were no observer effects on DSRs in any habitat. In 2003, artificial nests ( n = 180; 120 contained a wax-filled egg) were deployed on study plots. The model that best explained variation in DSRs for artificial nests included only 1 variable: habitat class (DSRs: island ≥ overwater > terrestrial). Mammalian predation of artificial nests (by foxes [ Vulpes vulpes ] and martens [ Martes spp.]) was more likely in terrestrial habitats than in littoral habitats or on islands. By contrast, corvids and marsh harriers ( Circus aeruginosus ) prevailed among predators of overwater and island nests. Our data indicate that artificial islands and wide strips of littoral vegetation may represent secure breeding habitats for waterfowl because those habitats allow nests to be placed in areas that are not accessible to, or that are avoided by, mammalian predators. Management actions should be aimed at preserving these habitats. This, along with creation of new artificial islands, could help to enhance breeding productivity of pochards and possibly other waterfowl species inhabiting man-made ponds.

Trebon Basin Biosphere Reserve↗

USGS1964

Spalled, aerodynamically modified moldavite from Slavice, Moravia, Czechoslovakia

A Czechoslovakian tektite or moldavite shows clear, indirect evidence of aerodynamic ablation. This large tektite has the shape of a teardrop, with a strongly convex, deeply corroded, but clearly identifiable front and a planoconvex, relatively smooth, posterior surface. In spite of much erosion and corrosion, demarcation of the posterior and the anterior part of the specimen (the keel) is clearly preserved locally. This specimen provides the first tangible evidence that moldavites entered the atmosphere cold, probably at a velocity exceeding 5 kilometers per second; the result was selective heating of the anterior face and perhaps ablation during the second melting. This provides evidence of the extraterrestial origin of moldavites.

Science↗

USGS1964

Paleozoic mollusk: Hyolithes

An unusually well-preserved Ordovician fossil from Czechoslovakia shows that the enigmatic paired structures once thought to be outgrowths of the operculum of Hyolithes are really independent structures lying between the operculum and the aperture of the shell. The find seems to provide conclusive proof of the morphologic uniqueness of hyolithids.

Science↗