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Márian Urban Rainer Thomas Vratislav Hurai Patrik Koneèný Martin Chovan 《Mineralium Deposita》2006,40(8):867-873
CO2 inclusions with density up to 1,197 kg m−3 occur in quartz–stibnite veins hosted in the low-grade Palaeozoic basement of the Gemericum tectonic unit in the Western Carpathians. Raman microanalysis corroborated CO2 as dominant gas species accompanied by small amounts of nitrogen (<7.3 mol%) and methane (<2.5 mol%). The superdense CO2 phase exsolved from an aqueous bulk fluid at temperatures of 183–237°C and pressures between 1.6 and 3.5 kbar, possibly up to 4.5 kbar. Low thermal gradients (∼12–13°C km−1) and the CO2–CH4–N2 fluid composition rule out a genetic link with the subjacent Permian granites and indicate an external, either metamorphogenic (oxidation of siderite, dedolomitization) or lower crustal/mantle, source of the ore-forming fluids.According to microprobe U–Pb–Th dating of monazite, the stibnite-bearing veins formed during early Cretaceous thrusting of the Gemeric basement over the adjacent Veporic unit. The 15- to 18-km depth of burial estimated from the fluid inclusion trapping PT parameters indicates a 8- to 11-km-thick Upper Palaeozoic–Jurassic accretionary complex overlying the Gemeric basement and its Permo-Triassic autochthonous cover. 相似文献
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Marine Protected Areas (MPAs) often fail to meet ecological, social or economic objectives due to lack of effective management by government institutions. Partly in response to this failure, a number of marine reserves managed by the private sector, Hotel Managed Marine Reserves (HMMRs), have recently been established. In this study, we investigate changes to the social and economic conditions faced by local fishermen, following the establishment of two small reserves adjacent to a hotel in Vietnam, as well as their perceptions of the reserves' ability to produce spillover. The findings are used to gauge management performance and effectiveness of the HMMRs. Two surveys with different survey designs, targeting fishermen with different fishing techniques, produced conflicting results. Fishermen mainly dependent on beach seining mostly opposed the HMMRs and the prospect of more protected areas being established. Fishermen using other fishing techniques were generally in favor of the HMMRs, welcoming more protection and confirming spillover of fish, including large food fishes. 相似文献
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Lise Byskov Herslund Fatemeh Jalayer Nathalie Jean-Baptiste Gertrud Jørgensen Sigrun Kabisch Wilbard Kombe Sarah Lindley Patrik Karlsson Nyed Stephan Pauleit Andreas Printz Trond Vedeld 《Natural Hazards》2016,82(2):149-172
In this paper, we develop and apply a multi-dimensional vulnerability assessment framework for understanding the impacts of climate change-induced hazards in Sub-Saharan African cities. The research was carried out within the European/African FP7 project CLimate change and Urban Vulnerability in Africa, which investigated climate change-induced risks, assessed vulnerability and proposed policy initiatives in five African cities. Dar es Salaam (Tanzania) was used as a main case with a particular focus on urban flooding. The multi-dimensional assessment covered the physical, institutional, attitudinal and asset factors influencing urban vulnerability. Multiple methods were applied to cover the full range of vulnerabilities and to identify potential response strategies, including: model-based forecasts, spatial analyses, document studies, interviews and stakeholder workshops. We demonstrate the potential of the approach to assessing several dimensions of vulnerability and illustrate the complexity of urban vulnerability at different scales: households (e.g., lacking assets); communities (e.g., situated in low-lying areas, lacking urban services and green areas); and entire cities (e.g., facing encroachment on green and flood-prone land). Scenario modeling suggests that vulnerability will continue to increase strongly due to the expected loss of agricultural land at the urban fringes and loss of green space within the city. However, weak institutional commitment and capacity limit the potential for strategic coordination and action. To better adapt to urban flooding and thereby reduce vulnerability and build resilience, we suggest working across dimensions and scales, integrating climate change issues in city-level plans and strategies and enabling local actions to initiate a ‘learning-by-doing’ process of adaptation. 相似文献
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Patrik Marquart 《Studia Geophysica et Geodaetica》1968,12(2):233-235
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Monika?HuraiováEmail author Jean?Dubessy Patrik?Kone?ny Klaus?Simon Ján?Král’ Grzegorz?Zielinski Jozef?Lipka Vratislav?Hurai 《Contributions to Mineralogy and Petrology》2005,148(5):615-633
Glassy orthopyroxene granodiorite-tonalite (named pincinite after type locality) was described from basaltic lapilli tuffs of the Pliocene maar near Pinciná village in the Slovakian part of the Pannonian Basin. Two pincinite types exhibit a qualitatively similar mineral composition (quartz, An20–55 plagioclase, intergranular silicic glass with orthopyroxene and ilmenite, ±K-feldspar), but strongly different redox potential and formation PT conditions. Peraluminous pincinite is reduced (6–7% of total iron as Fe3+ in corundum-normative intergranular dacitic glass) and contains ilmenite with 8–10 mol% Fe2O3 and orthopyroxene dominated by ferrosilite. High-density (up to 0.85 g/cm3) primary CO2 inclusions with minor H2, CH4, H2S, CO and N2 (<2 mol% total) are present in Qtz and Plg. Equilibrium PT conditions inferred from the intergranular Opx–Ilm–Glass assemblage and fluid density correspond to 1,170±50°C, 5.6±0.4 kbar, respectively. Metaluminous pincinite is more oxidised (25–27% of total iron as Fe3+ in diopside-normative intergranular glass of rhyolite–trachyte–dacite composition) and contains Fe2O3-rich ilmenite (17–29 mol%) associated with enstatite. Fluid inclusions are composed of CO2–H2O mixtures with up to 38 mol% H2O. Raman spectroscopy revealed H2S along with dominant CO2 in the carbonic phase. Equilibrium PT parameters for the intergranular Opx–Ilm–Glass assemblage correspond to 740±15°C, 2.8±0.1 kbar, respectively. Reducing gas species (<2 mol% total) in the CO2-inclusions of the peraluminous pincinite resulted from hydrogen diffusion due to fH2 gradient imposed during decrease of redox potential from the log fO2 values near QFM during Qtz + Plg growth, to QFM-2 incidental to the superimposed Opx + Ilm assemblage in the intergranular melt. The decrease in oxygen fugacity was recorded also in the metaluminous pincinite, where log fO2 values changed from ~QFM + 2.6 to QFM + 0.4, but hydrogen diffusion did not occur. Absence of OH-bearing minerals, major and trace element abundances (e.g. REE 300–320, Nb 55–57, Th 4–31, Zr 240–300 ppm, FeOtot/MgO up to 11), and Sr–O isotope ratios in the pincinites are diagnostic of high-temperature anorogenic magmas originated by dehydration melting of biotite in quartz-feldspathoid crust (87Sr/86Sr>0.705–0.706, 18O>9 V-SMOW) around alkali basalt reservoir in depths between 17 and 20 km, and around late stage derivatives of the basalt fractionation, intruding the crust up to depths of 10–11 km. Low water activity in the pincinite parental melt was caused by CO2-flux from the Tertiary basaltic reservoirs and intrusions. The anatexis leads to generation of a melt-depleted granulitic crust beneath the Pannonian Basin, and the pincinites are interpreted as equivalents of igneous charnockites and enderbites quenched at temperatures above solidus and unaffected by sub-solidus re-equilibration and metamorphic overprint. 相似文献
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The Jalovecký Creek catchment, Slovakia (area 22.2 km2, mean elevation 1500 m a.s.l.), is likely the last big valley complex in the Carpathian Mountains, in which the hydrological cycle is still governed by natural processes. Hydrological research is conducted there since the end of the 1980s. The overall mission of the research is to increase the knowledge about the hydrological cycle in the highest part of the Carpathians. The research agenda, briefly introduced in the first part of this article, is focused on water balance, snow accumulation and melt and runoff formation. Recent analysis of precipitation, discharge, snow cover and isotopic data from period 1989–2018 indicates that hydrological cycle has become more dynamic since 2014. Although several indicators suggest that it could be related to the cold part of the year, direct links with snow storage and the contribution of snowmelt water to catchment runoff were not confirmed. The second part of the article is therefore focused on an analysis of daily cycles in streamflow in March to June 1988–2018 to obtain a deeper insight into the snowmelt process. We describe characteristics of the cycles and examine their variability over the study period. The results indicate that less snow at the lowest elevations (800–1150 m a.s.l.) since 2009 could have influenced the cessation of the cycles in June since 2010. The possible role of the decreased amount of snow at the lowest elevations in changes in runoff characteristics is also suggested by an increase in time lags between maximum discharges during the events and maximum air temperatures preceding discharge maxima measured near the catchment outlet (at 750 m a.s.l.) in spring 2018 compared to springs with a similar number of streamflow cycles in the years 1988, 2000 and 2009. Wavelet analysis did not indicate changes in global power spectra in hourly discharge and air temperature data. 相似文献
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Inga Golbeck Xin Li Frank Janssen Thorger Brüning Jacob W. Nielsen Vibeke Huess Johan Söderkvist Bjarne Büchmann Simo-Matti Siiriä Olga Vähä-Piikkiö Bruce Hackett Nils M. Kristensen Harald Engedahl Ed Blockley Alistair Sellar Priidik Lagemaa Jose Ozer Sebastien Legrand Patrik Ljungemyr Lars Axell 《Ocean Dynamics》2015,65(12):1603-1631
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Root properties of vegetation communities and their impact on the erosion resistance of river dikes 总被引：1，自引：0，他引：1 
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下载免费PDF全文 Wouter Vannoppen Jean Poesen Patrik Peeters Sarah De Baets Bart Vandevoorde 《地球表面变化过程与地形》2016,41(14):2038-2046
Predicted climate change and the associated sea level rise poses an increased threat of flooding due to wave overtopping events at sea and river dikes. To safeguard the land from flooding it is important to keep the soil erosion resistance at the dikes high. As plant roots can be very effective in reducing soil erosion rates by concentrated flow, the main goal of this study is to explore the variability in root system characteristics of five dike vegetation communities along the Scheldt River (Belgium) and to assess their effectiveness in controlling soil erosion rates during concentrated flow. This study is the first one to investigate systematically the erosion‐reducing potential of the root properties of representative dike vegetation communities in a temperate humid climate. Results show that the presence of Urtica dioica resulted in large differences in root length density (RLD) among dike vegetation communities. Observed RLD values in the topsoil ranged from 129 to 235 km m‐3 for dike vegetation communities without U. dioica, while smaller values ranging from 22 to 58 km m?3 were found for vegetation communities with U. dioica. The erosion‐reducing effect of the dike vegetation communities was estimated based on a global Hill curve model, linking the RLD to the soil detachment ratio (SDR; i.e. the ratio of the soil detachment rate for root‐permeated topsoils to the soil detachment rate for root‐free topsoils). Concentrated flow erosion rates are likely to be reduced to 13–16% of the erosion rates for root‐free topsoils if U. dioica is absent compared to 22–30% for vegetation communities with U. dioica. Hence, to maintain a high resistance of the soil against concentrated flow erosion it is important to avoid the overgrowth of grassland by U. dioica through an effective vegetation management. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献