Total Hg concentrations and Hg speciation were determined in bottom sediments of Marano lagoon to investigate the consequences of Hg phases on fish farms and shellfish cultivation areas. Mercury ...phases were separated into cinnabar (HgS) and non-cinnabar compounds, via a thermo-desorption technique, in surface and core sediments; both of which had been contaminated by industrial wastes and mining activity residues. The former are due to an industrial complex, which has been producing cellulose, chlor-alkali and textile artificial fibres since 1940. Processing and seepage wastewaters, which were historically discharged into the Aussa-Corno river system and therefore into the lagoon, have been significantly reduced since 1984 due to the construction of wastewater treatment facilities. The second source is the Isonzo River, which has been the largest contributor of Hg into the northern Adriatic Sea since the 16th century due to Hg mining at the Idrija mine (western Slovenia). Red cinnabar (HgS) derived from the mining area is mostly stable and insoluble under current environmental conditions. In contrast, organically bound Hg, such as Hg bound to humic acids, has the potential to be transformed into bioavailable Hg compounds (for example, methylmercury). The presence of the two Hg forms permitted each Hg source to be quantified. It also allowed the areas with the highest risk of Hg contamination from Hg-rich sediment to be identified; thus potentially avoiding the transfer of Hg from the sediment into the water column and eventually into living biota. The results show that Hg Enrichment Factors in bottom sediments exceed values of 10 and cinnabar dominates the central sector near the main tidal channel where tidal flux is more effective. Non-cinnabar compounds were found to be enriched in fine grained material and organic matter. In fact, up to 98% of total Hg at the Aussa-Corno river mouth and in the inner margin of the basin occurred in an organic form. This evidence, combined with the high contents of total Hg (4.1–6.6
μg
g
−1 and EF
>
10) measured in surface sediments, suggest that Hg in Marano lagoon is involved in biogeochemical transformations (e.g., methylation).
The 1511 Western Slovenia earthquake (
M
=
6.9) is the largest event occurred so far in the region of the Alps–Dinarides junction. Though it strongly influences the regional seismic hazard ...assessment, the epicenter and mechanism are still under debate. The complexity of the active tectonics of the Alps–Dinarides junction is reflected by the presence of both compressional and transpressional deformations. This complexity is witnessed by the recent occurrence of three main earthquake sequences, the 1976 Friuli thrust faulting events, the 1998 Bovec–Krn Mountain and the 2004 Kobarid strike-slip events. The epicenters of the 1998 and 2004 strike-slip earthquakes (
M
s
=
5.7 and
M
s
=
4.9, respectively) lie only 50 km far from the 1976 thrust earthquake (
M
s
=
6.5).
We use the available macroseismic data and recent active tectonics studies, to assess a possible epicenter and mechanism for the 1511 earthquake and causative fault. According with previous works reported in the literature, we analyze both a two-and a single-event case, defining several input fault models. We compute synthetic seismograms up to 1 Hz in an extended-source approximation, testing different rupture propagations and applying a uniform seismic moment distribution on the fault segments. We extract the maximum horizontal velocities from the synthetics and we convert them into intensities by means of an empirical relation. A rounded-to-integer misfit between observed and computed intensities is performed, considering both a minimized and a maximized databases, built to avoid the use of half-degree macroseismic intensity data points. Our results are consistent with a 6.9 magnitude single event rupturing 50 km of the Idrija right-lateral strike-slip fault with bilateral rupture propagation.
From the historic literature on the Idrija mercury mine, it is evident that part of the smelting and mining waste was dumped into the Idrijca River. This waste was transported downstream during ...floods. The amount of mercury which has accumulated in the alluvial sediments of the Idrijca River until the present was studied. Mapping of Holocene river terraces of the Idrijca River was performed in order to estimate the volume of the alluvial sediment. For the purpose of the assessment of the mercury concentration, we sampled the alluvial sediments on different levels and performed an analysis of variance. The greatest variability is between the floodplain and terraces inside the same alluvial plain. Considering this fact, which determined the methodology employed for calculation, we estimated that about 2029 tons of mercury is stored in the Idrijca River alluvial sediments.
Half a millennium of mercury production at Idrija is reflected in increased mercury contents in all of its environmental segments. Stream sediments have been monitored along the Idrijca and Soca ...rivers (70 km) every 5 years since 1991. It has been discovered that there was no decrease in mercury concentration in stream sediments during the last 15 years. Upstream from the town of Idrija, mercury concentrations in active river sediments vary from 1 to 10 mg/kg dry weight (average 3.3 mg/kg). From Idrija to Spodnja Idrija mercury concentrations increase extremely and vary greatly. The average in this area amounts to 603 mg/kg with individual contents up to 4121 mg/kg. From Spodnja Idrija to the Idrijca-Soca confluence the average is 213 mg/kg, while the average in the Soda river sediments is 57 mg/kg. Floodplain soils and samples of averaged meadow forage and plantain (Plantago lanceolata) were collected on river terraces at two localities in the lower course of the Idrijca. It has been determined that floodplains along the Idrijca River are strongly enriched with mercury. The average concentration of Hg in the upper 20 cm of the floodplain at IDB location is 157.7 and at TEM location it is 294.8 mg/kg. Samples of averaged meadow forage and plantain contain from 0.055 to 0.220 mg Hg/kg. In comparison to the plant samples from Idrija in the 1970s, these contents are relatively low. However, regarding mercury contents in plants in non-polluted soils the contents on the Idrijca River terraces are considerably higher than the background.
The abandoned Hg mine in Podljubelj was in operation with interceptions from 1557 to 1902. The entire operating period yielded about 110
000 tons of ore, from which 360 tons of Hg was produced. The ...objective of the research project was to establish the contents and spatial distribution of Hg in soils and stream sediments in the vicinity of the mine. On an area of 88 ha the soil was sampled in a 100
×
100 m grid. Two soil horizons (0–5 cm and 20–30 cm) were sampled in order to distinguish between geogenic and anthropogenic Hg sources. It was established that on an area of about 9 ha Hg content in soil exceeds The New Dutchlist action value for Hg (10 mg/kg). Total Hg concentrations in soil samples vary between 0.17 and 719 mg/kg, with a mean of 3.0 mg/kg. Mercury contents in stream sediments range from 0.065 to 1.4 mg/kg, with a mean of 0.64 mg/kg. The highest determined value in soils was found in the area around the former roasting furnace, where the ore was processed. Increased Hg concentrations were also found on the mine waste dump (108 mg/kg). Mercury contents in soils generally decrease with soil profile depth and with the distance from the mine and from the roasting furnace location. Mercury also appears in higher concentrations along the road that runs through the valley, which results from the use of Hg-bearing ore residues in road construction. The average enrichment factor (EF) of Hg in topsoil with respect to subsoil is 3.3. Calculated enrichment factors show higher values also for Cd (3.2), Pb (2.7), Ca (2.4) and P (1.9). The average enrichment factor of Hg in topsoil with regard to the established Slovenian soil averages (EF
slo) is 19. EF
slo of other determined chemical elements do not exceed 3.0.
Mercury emission measurements from the Idrija mercury mine in Slovenia were performed during an early November 2003 campaign, where the differential lidar technique was used to map mercury ...concentrations and an attempt was made to quantify the total mercury flux from the most contaminated area, the abandoned cinnabar roasting oven complex. Lidar concentration data were compared with data recorded with a Zeeman modulated atomic absorption instrument, operated from a vehicle equipped with a GPS localization system. Concentrations and fluxes were comparatively low due to low temperature and rainfall. The average flux from the distillation plant was measured to approximately 2
g
h
−1.
The Alps are one of the most sensitive regions in Europe, and their future development represents a challenge that demands the cooperation of various experts, the business world, politics, and ...society, as well as the people living there. The Interreg IIIB project DIAMONT, which took place from 2005 to 2008, also addressed Alpine developmental challenges. This monograph presents the basic results of the project, supported by the broader theoretical framework of regional and sustainable development. We first present the cultural differences in the Alps and their influence on sustainable regional development. This is followed by the results of a Delphi analysis, which helped reveal the basic development tendencies in the Alps, and then we discuss appropriate indicators for regional development and harmonizing data. Attention is then dedicated to regional development instruments and the participative process, which is essential for attaining truly sustainable development. Finally, we present a Slovenian perspective on these issues.
The world-class Idrija mercury deposit (western Slovenia) is hosted by highly deformed Permocarboniferous to Middle Triassic sedimentary rocks within a complex tectonic structure at the transition ...between the External Dinarides and the Southern Alps. Concordant and discordant mineralization formed concomitant with Middle Triassic bimodal volcanism in an aborted rift. A multiple isotopic (C, O, S) investigation of host rocks and ore minerals was performed to put constraints on the source and composition of the fluid, and the hydrothermal alteration. The distributions of the δ^sup 13^C and δ^sup 18^O values of host and gangue carbonates are indicative of a fracture-controlled hydrothermal system, with locally high fluid-rock ratios. Quantitative modeling of the δ^sup 13^C and δ^sup 18^O covariation for host carbonates during temperature dependent fluid-rock interaction, and concomitant precipitation of void-filling dolomites points to a slightly acidic hydrothermal fluid (δ^sup 13^Casymptotically =-4per thousand and δ^sup 18^Oasymptotically =+10per thousand), which most likely evolved during isotopic exchange with carbonates under low fluid/rock ratios. The δ^sup 34^S values of hydrothermal and sedimentary sulfur minerals were used to re-evaluate the previously proposed magmatic and evaporitic sulfur sources for the mineralization, and to assess the importance of other possible sulfur sources such as the contemporaneous seawater sulfate, sedimentary pyrite, and organic sulfur compounds. The δ^sup 34^S values of the sulfides show a large variation at deposit down to hand-specimen scale. They range for cinnabar and pyrite from -19.1 to +22.8per thousand, and from -22.4 to +59.6per thousand, respectively, suggesting mixing of sulfur from different sources. The peak of δ^sup 34^S values of cinnabar and pyrite close to 0per thousand is compatible with ore sulfur derived dominantly from a magmatic fluid and/or from hydrothermal leaching of basement rocks. The similar stratigraphic trends of the δ^sup 34^S values of both cinnabar and pyrite suggest a minor contribution of sedimentary sulfur (pyrite and organic sulfur) to the ore formation. Some of the positive δ^sup 34^S values are probably derived from thermochemical reduction of evaporitic and contemporaneous seawater sulfates.PUBLICATION ABSTRACT
Stream and flood plain sediments along the valley of the Idrijca River were systematically sampled. Upstream of the mercury mining town of Idrija, the Hg in stream sediment varies around 2 mg/kg. ...Mecury contents in the region from Idrija downstream to the town of Spodnja Idrija are from 100 to 1, 000 mg/kg. Downstream from Spodnja Idrija, sediments contain lower Hg (from 5 to 300 mg/kg). Recent overbank sediments are enriched relative to the stream sediments downstream of Idrija. River flood plain sediments that represent an accumulation of polluted sediments have Hg contents of 100 to 200 mg/kg.
PDF
