Shallow and sheltered marine embayments in urbanized areas are prone to the accumulation of pollutants, but little is known about the historical baselines of such marine ecosystems. Here we study ...foraminiferal assemblages, geochemical proxies and sedimentological data from 1.6 m long sediment cores to uncover ∼ 500 years of anthropogenic pressure from mining, port and industrial activities in the Gulf of Trieste, Italy. From 1600 to 1900 AD, normalized element concentrations and foraminiferal assemblages point to negligible effects of agricultural activities. The only significant anthropogenic activity during this period was mercury mining in the hinterlands of the gulf, releasing high amounts of mercury into the bay and significantly exceeding the standards on the effects of trace elements on benthic organisms. Nonetheless, the fluctuations in the concentrations of mercury do not correlate with changes in the composition and diversity of foraminiferal assemblages due to its non-bioavailability. Intensified agricultural and maricultural activities in the first half of the 20th century caused slight nutrient enrichment and a minor increase in foraminiferal diversity. Intensified port and industrial activities in the second half of 20th century increased the normalized trace element concentrations and persistent organic pollutants (PAH, PCB) in the topmost part of the core. This increase caused only minor changes in the foraminiferal community because foraminifera in Panzano Bay have a long history of adaptation to elevated trace element concentrations. Our study underlines the importance of using an integrated, multidisciplinary approach in reconstructing the history of environmental and anthropogenic changes in marine systems. Given the prolonged human impacts in coastal areas like the Gulf of Trieste, such long-term baseline data are crucial for interpreting the present state of marine ecosystems.
Mercury (Hg) concentrations and Hg phases were investigated in contaminated sediments and flooded soils in the drainage area of the Idrija Hg mine, Slovenia. The main aim of this study was the ...analytical separation and quantification of cinnabar (HgS) and noncinnabar Hg compounds in sediments contaminated by mining residues. Separation of Hg phases was performed by means of a solid-phase-Hg-thermo-desorption technique complemented by selective extraction of organically bound Hg. Speciation measurements indicate the occurrence of two major Hg forms: cinnabar the primary ore and an unspecified group of matrix-bound, noncinnabar Hg compounds. The results show that Hg concentrations and dispersion of the two Hg phases within the river system depend on the distribution of different sediment grain size fractions. Accumulation of cinnabar predominately occurs in coarse grained river sediments, where it constitutes on average more than 80% of total Hg (up to 1000 mg/kg) in present- and past day sediments. In contrast noncinnabar Hg was found to be enriched in areas where fine grained material was deposited reaching up to 40% of Hgtot (1−60 mg/kg) in flooded soils and up to 55% (<1−18 mg/kg) in sediments of the Gulf of Trieste.
Five centuries of mining and processing of mercury ore in the Idrija area have resulted in widespread contamination of different environmental compartments. Environmental impacts on a regional and ...local scale, caused by atmospheric emissions from the Idrija ore roasting plant, were established in the investigations of mercury spatial distribution in soil and attic dust in 160 km
2
area. Very high values were determined in the Idrijca River valley, and they decrease exponentially with the distance from Idrija. Mercury concentrations in attic dust are higher than in surrounding soils and the attic dust/soil ratio changes with distance. Measurements of mercury in the air confirmed widespread dispersion of mercury and showed highly elevated mercury concentrations around roasting plant and mine ventilation shaft. Beside, systematic monitoring of mercury contents in the stream sediments has demonstrated that huge amounts of mercury are stored in areas where ancient overbank sediments were deposited, and there was no decrease in mercury concentration in active sediments during the last 15 years. Recently, interesting and extremely polluted locations of historical small-scale roasting sites in the Idrija surroundings were discovered. Ongoing geochemical study aims to determine the extreme pollution and significance of these sites for wider contamination of soils and aquatic systems. Presented studies have shown that Hg mining in Idrija caused intense pollution of local and regional environment including the aquatic systems in the Gulf of Trieste, which is seen as the final sink of a major part of the Hg stored in soils and river sediments in the Idrija area.
Common cyclamen (Cyclamen purpurascens Mill.) is the only representative of its genus in Slovenia where it is a widespread species, growing from sea level to high mountainous areas. It thrives in all ...four major phytogeographic regions: Alpine, Dinaric, sub-Pannonian and sub-Mediterranean, in both transitional regions, pre-Alpine and pre-Dinaric, and it reacts quickly to weather conditions. It is found mostly in deciduous and mixed forests, at forest margins and in mountain meadows. In the highlands, it often grows on gravel and can also be found in fairly low-scree areas. As such, it is expected to shows great intraspecific diversity. Based on a collection of 6000 units of C. purpurascens specimens collected in different parts of Slovenia, we were able to determine different types of C. purpurascens and describe new varieties. All of the specimens were divided into four groups with respect to leaf pattern, which is the most durable distinguishing feature. The four dividing groups were silvery, semi-silvery, marbled and green. The most notable variety in the silvery group was C. purpurascens ‘Idrija’, while in the semi-silvery group, it was C. purpurascens ‘Nova Gorica’, in the marbled group, it was ‘C. purpurascens ‘Slivje’ and in the green group, it was C. purpurascens ‘Podsreda’.
Cultural and natural elements contribute to the development of rural areas. Identifying and evaluating development aspects and the interconnection of cultural values and local stakeholders are key to ...managing cultural values. This article defines cultural values with development potential by studying the relevant research literature and legislation, carrying out field studies in the Idrija countryside, and using an online questionnaire to evaluate development aspects.
Results are presented of the first airborne LiDAR survey ever flown in Europe for the purpose of mapping the surface expression of earthquake‐prone faults. Detailed topographic images derived from ...LiDAR data of the Idrija and Ravne strike‐slip faults in NW Slovenia reveal geomorphological and structural features that shed light on the overall architecture and kinematic history of both fault systems. The 1998 MW = 5.6, and 2004 MW = 5.2 Ravne Fault earthquakes and the historically devastating 1511 M = 6.8 Idrija earthquake indicate that both systems pose a serious seismic hazard in the region. Because both fault systems occur within forested terrain, a tree removal algorithm was applied to the data; the resulting images reveal surface scarps and tectonic landforms in unprecedented detail. Importantly, two sites were discovered to be potentially suitable for fault trenching and palaeo‐seismological analysis. This study highlights the potential contribution of LiDAR surveying in both low‐relief valley terrain and high‐relief mountainous terrain to a regional seismic hazard assessment programme. Geoscientists working in other tectonically active regions of the world where earthquake‐prone faults are obscured by forest cover would also benefit from LiDAR maps that have been processed to remove the canopy return and reveal the forest floor topography.
The rise and demise of warm-temperate Permian reefs and biostromes reflect the complex geologic history of this dynamic period. Environments suitable for reef-builders were devastated by the ...Guadalupian/Lopingian crisis, and Lopingian reefs have only been recorded at a small number of localities. The uppermost Permian limestones of the Bellerophon Formation, on the Vojsko Plateau (Slovenia), contain small, lenticular biostromes within a bioclastic wackestone/packstone lithofacies. The major biostrome builders are medium-sized coralline sponges (Demospongea and Calcarea), encrusted by smaller sponges, tube worms, sessile foraminifera, calcareous algae (Archaeolithoporella) and Shamovella (i.e., Tubiphytes), all of which are typically covered by microbial crusts. The biostromes are characteristically composed of bafflestone and bindstone, incorporating sporadic framestone. Narrow belts of floatstone surround the buildups, and sponge debris is also present in lenses within the mud matrix between metazoan bafflestones. The fossils are generally well-preserved, although the fine skeletal microstructure has been partially recrystallized. Sponges are heavily calcified, and ontogenic thickening of the skeleton can be observed in some encrusters. Framboidal pyrite, forming thin films on the inner walls of sponge chambers, suggests the presence of sulphate-reducing bacteria. These microbial symbionts may have enabled the sponges to survive in the anoxic marine environments of the uppermost Permian. The Changshingian sponge biostromes of the Vojsko Plateau represent the westernmost known occurrence of contemporary metazoan boundstones in the Palaeotethys.
•Small sponge biostromes occur in the uppermost Permian of Slovenia.•Demospongea and Calcarea acted as sediment baffles, and were often encrusted by microbes.•Pyrite framboids indicate that sponges had a symbiotic relationship with sulphate-reducing bacteria.•These symbionts helped sponges to survive in hot, anoxic environments.•Plate tectonics contributed to the loss of suitable reef habitats in the Palaeotethys in the Late Permian.
The role of the major biogeochemical processes in Hg cycling at the sediment–water interface was investigated in the Grado Lagoon (Northern Adriatic Sea). This wetland system has been extensively ...contaminated from the Idrija Hg Mine (Slovenia) through the Isonzo River suspended load carried by tidal fluxes. Three approaches were used to study the sediment–water exchange of total Hg (THg), methylmercury (MeHg), reactive Hg (RHg) and dissolved gaseous Hg (DGHg): (1) estimation of diffusive fluxes from porewater and overlying water concentrations, (2) measurements of benthic fluxes using a deployed light benthic chamber
in situ and (3) measurements of benthic fluxes during oxic–anoxic transition with a laboratory incubation experiment. The THg solid phase, ranging between 9.5 and 14.4
μg
g
−1, showed slight variability with depth and time. Conversely, MeHg contents were highest (up to 21.9
ng
g
−1) at the surface; they tended to decrease to nearly zero concentration with depth, thus suggesting that MeHg production and accumulation occur predominantly just below the sediment–water interface. Porewater MeHg concentrations (0.9–7.9
ng
L
−1, 0.15–15% of THg) varied seasonally; higher contents were observed in the warmer period. The MeHg diffusive fluxes (up to 17
ng
m
−2
day
−1) were similar to those in the nearby Gulf of Trieste Covelli, S., Horvat, M., Faganeli, J., Brambati, A., 1999. Porewater distribution and benthic flux of mercury and methylmercury in the Gulf of Trieste (Northern Adriatic Sea). Estuar. Coast. Shelf Sci. 48, 415–428, although the lagoon sediments contained four-fold higher THg concentrations. Conversely, the THg diffusive fluxes in the lagoon (up to 110
ng
m
−2
day
−1) were one- to two-fold higher than those previously estimated for the Gulf of Trieste. The diurnal MeHg benthic fluxes were highest in summer at both sites (41,000 and 33,000
ng
m
−2
day
−1 at the fishfarm and in the open lagoon, respectively), thus indicating the influence of temperature on microbial processes. The diurnal variations of dissolved THg and especially MeHg were positively correlated with O
2 and inversely with DIC, suggesting an important influence of benthic photosynthetic activities on lagoon benthic Hg cycling, possibly through the production of organic matter promptly available for methylation. The results from the dark chamber incubated in the laboratory showed that the regeneration of dissolved THg was slightly affected by the oxic–anoxic transition. Conversely, the benthic flux of MeHg was up to 15-fold higher in sediments overlain by O
2 depleted waters. In the anoxic phase, the MeHg fluxes proceeded in parallel with Fe fluxes and the methylated form reached approximately 100% of dissolved THg. The MeHg is mostly released into overlying water (mean recycling efficiency of 89%) until the occurrence of sulphide inhibition, due to scavenging of the available Hg substrate for methylation. The results suggest that sediments in the Grado Lagoon, especially during anoxic events, should be considered as a primary source of MeHg for the water column.
Mercury (Hg) solubility and reactivity in soils at two extremely contaminated ancient small scale cinnabar roasting sites in the surroundings of the Hg mining area of Idrija (Slovenia) were ...determined in order to assess the mobility of Hg in the aqueous phase and to evaluate the extent of leaching of Hg into Idrijca River and further downstream. Water leaching experiments were performed on soil and SOM (soil organic matter) samples from historical roasting sites Pšenk and Frbejžene trate. The determined concentrations of leachable Hg in soil samples from the studied areas range from 16 to exceptionally high concentration of 18,000μg/kg, representing 0.0002 to 1.1% of total Hg in these samples, while in SOM samples leachable Hg concentrations range between 13.3 and 6000μg/kg, which corresponds to 0.0017–0.074% of total Hg determined in SOM. The soluble Hg concentrations in investigated soil profiles range from 183 to 18,000μg/kg (0.038–1.7% of total Hg). On the average, more than 90% of soluble Hg occurs in a non-reactive complex bound form, suggesting the preferential binding of Hg to humic matter. Soluble Hg in studied soil profiles generally increases with depth. The obtained results show that Hg is effectively transported to deeper soil layers, mainly as soluble organic complexes. It is estimated that there is still about 10kg of soluble Hg stored in soils of the investigated roasting sites, which is continuously leached to surface waters and deeper into the soil.
•Water leaching experiments were performed on soil and SOM samples.•Total soluble, complex-bound and reactive Hg was defined.•Extremely high concentrations (up to 18,000μg/kg) of soluble Hg were determined.•More than 90% of soluble Hg occurs in a non-reactive complex bound form.•We estimate that soluble Hg stored in soils is mobilized to the groundwater.
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