We present new isotope (C, He, Ne, Ar, partly N) and compositional data from the free gas phase of fourteen degassing sites in the westernmost part of the Pannonian Basin near the Austria/Slovenia ...borderline. Based on these data, the origin of the gases and the degree of modification of the gas signatures due to interaction processes during migration are evaluated. The isotope signatures indicate an origin of helium and CO2 predominantly in the subcontinental mantle. Measured 3He/4He ratios from 4.95 to 6.32 Ra include the highest ones recorded in the whole Pannonian Basin system. Only at three locations in the periphery of the degassing center, a substantial admixture of crustal helium was found. The CO2 in the mofette gases and at the sites with the highest 3He/4He ratios (~6.3 Ra) is characterized by δ13C values of −3.5‰. In comparison with MORB (Mid-ocean Ridge Basalt), it is thus slightly enriched in 13C. The 3He/4He isotope ratios within the range typical for the subcontinental lithospheric mantle (SCLM) point to a fast, localized fluid transport from the magmatic reservoir to the surface.
There are only few sites in European non-active volcanic regions where free gases with unmodified SCLM helium isotope signature escape at the surface. A comparison of the elemental and isotopic geochemical characteristics of gases with SCLM-helium signature from four different regions (Massif Central/France, Eifel/Germany, Eger Rift/Czech Republic and the westernmost part of the Pannonian Basin system) indicates that the European SCLM in general is characterized by a reservoir more enriched in 13C compared to MORB.
•Highest fractions of mantle-derived He in the Pannonian Basin system were recorded.•CO2–He systematics traces ongoing magma degassing at the Austria/Slovenia border.•Uppermost mantle below Austria/Slovenia shows SCLM isotope signature of He and CO2.•Characterization of SCLM carbon signature using free gases with SCLM-type He.
Traditional ecological knowledge of plants is an important aspect of scholarship in relation to land use and contributes to the sustainable use and management of natural resources as well as to the ...monitoring of changes in the natural environment. The aim of the present paper was to examine traditional ecological knowledge in Hungarian communities in Slovenia in connection with knowledge of the plants growing in the region, their local names, and their uses. We quantified the earlier role of the utilized plant species in order to determine the former significance of certain species. We carried out structured interviews with a total of 20 individuals in three studied settlements. In the Hungarian communities in Slovenia, we uncovered knowledge of a total of 130 folk taxa. Of these, 123 taxa have local names. The majority of the folk taxa can be correlated with a single biological species. A significant proportion of the known species were utilized in some way, most of them as medicinal plants, wild edible plants, or ornamental plants. As in other farming communities, the most important species are mainly woody plants, which include the common hornbeam, the common juniper, and the silver birch. Among the herbaceous plants, utilization of the dandelion, nettle, and bulrush was significant. Members of the older generations living in the Hungarian communities in Slovenia still retain knowledge of plants that were once used on a daily basis, along with their local names and the traditional ecological knowledge connected with their earlier use.
The objectives of this study are as follows: (a) an assessment of the geochemical background signature of the Drava Valley before the industrial revolution; (b) an evaluation of anthropogenic ...geochemical influences on the alluvial plains and river terraces in the valley; and (c) a determination of the spatial distribution of trace elements in the alluvial soils of the Drava River downstream of the Austrian–Slovenian border to the confluence of Mura and Drava Rivers.
Samples of topsoil (depth of 0–5
cm) and subsoil (depth of 20–30
cm) were collected from 134 sampling sites on alluvial plains and river terraces. Analysis for 41 chemical elements was performed. Based on a comparison of statistical parameters, the spatial distribution of particular elements and the results of factor analysis, one anthropogenic and three natural geochemical associations were identified. The anthropogenic association (As–Ba–Cd–Mo–Pb–Sb–Zn) is mostly a result of historical zinc and lead mining and smelting in the Drava River watershed. The natural geochemical associations (Al–Fe–K–Co–Cr–Cu–Li–Ni–Rb–Sc–Th, Ti–Ce–La–Nb–Ta and Ca–Mg–Sr) were mainly influenced by lithology. The entire assessed area of about 130
km
2 is, according to Slovenian and Croatian legislation, critically polluted with trace elements, especially zinc.
► Mines and smelters contributed to the Drava alluvial sediments. ► One anthropogenic and three natural geochemical associations were identified. ► Al–Fe–K–Co–Cr–Cu–Li–Ni–Rb–Sc–Th, Ti–Ce–La–Nb–Ta and Ca–Mg–Sr are effects of lithology. ► As–Ba–Cd–Mo–Pb–Sb–Zn is influenced by historical zinc and lead mining and smelting.
This paper investigates depletion rates and available thermal water resources of the transboundary Upper Pannonian loose sandstone geothermal aquifer of the Mura Formation in the Mura-Zala ...sedimentary basin in north-eastern Slovenia, and outlines a regional reinjection strategy to mitigate depletion. The research monitoring network of 12 geothermal wells, which is being constantly upgraded since 2009, has highlighted that the current abstraction rate of 2.4 million m
3
in 2014 is not sustainable because hydraulic state has been continuously deteriorating regionally while the chemical state is affected only locally. The average regional drawdown rate in observation wells is 0.67 m annually, while very rough average value for abstraction wells is 3.0 m per year. The cumulative historical regional drawdown is above 16 m. The available thermal water resources are addressed as the cumulative abstraction rate which reverses the observed declining trend of groundwater levels, and were numerically assessed to be ~1.3 million m
3
of thermal water per year. These numerical models set up in the AUTOUGH2 code also provided the quantification tool of the regional groundwater balance and confirmed the gravity-driven regional groundwater flow with prevailing conductive heat transfer mechanism. Simulations of the regional reinjection strategy outline that the cumulative reinjection rate of ~1.48 million m
3
of thermal water per year should be sufficient to reach good status of the aquifer if the cumulative regional abstraction rate does not change. If it does, the rate should be adjusted accordingly. The water is provided by eight users of geothermal heat and should be returned by the existing reinjection wells in Lendava and Murska Sobota and two new wells situated in the central part of the basin by 2021 the latest. These findings should enhance optimization of exploitation practice and implementation of geothermal doublets in the region as the successful example of a doublet in Lendava exemplifies that no major technological issues should occur if the system is properly designed.
► High contents of Zn, Pb, Cr, Ni, Cu, Co were determined in the Meža River sediments. ► Metal-bearing phases were identified in sediments and assigned to three source areas. ► Main sources of metals ...in the Meža River sediments are mine waste deposits, iron-steel industry, bedrock weathering. ► Contribution of the Meža River to the total metal-load in the Drava River is evident.
The Meža River Valley has been a center of mining, ore processing and iron- and steel-based metallurgical industry for more than 300 a. This paper deals with stream sediments draining this area. Loads of potentially toxic metals and metal-bearing phases were investigated 10 a after the cessation of Pb and Zn mining. Sediments in the upper Meža River Valley show significant pollution with Pb and Zn as a consequence of mining and ore processing. The highest contents of Pb and Zn were found in the Meža tributaries, which directly drain mine waste deposits (maximum values: 19,300
mg/kg Pb and 37,900
mg/kg Zn). These results reflect transport of contaminated material from mine waste sites and indicate that the inactive mine and its mine wastes are sources of metal contamination in the surrounding environment. Contents of Cr, Ni, Cu and Co are increased in the lower Meža River Valley, in the area of Ravne, as a result of the iron and steel industry. The contribution of the Meža River to the metal-load in the Drava River is evident.
Metal-bearing phases, identified in stream sediments by SEM/EDS, are assigned to three areas, according to their source and genesis. The Mežica mining district source area is characterized by ore minerals of geogenic/technogenic origin (cerussite, sphalerite, smithsonite and galena), the Ravne source area is characterized by technogenic trace metal-bearing Fe-alloys, Fe-oxides and spherical trace metal-oxides and the Meža and Drava River catchment areas are represented by geogenic metal-bearing accessory and common rock-forming minerals, such as zircon, ilmenite, rutile, sphene, barite and monazite. SEM/EDS analyses of stream sediments agree well with the results of chemical analyses and they prove to be a very useful tool for identification of metal-bearing phases and their characterization according to source and genesis.
•Geothermal aquifers in the Mura-Zala basin have been overexploited.•Aquifers’ depletion is reflected in hydraulic and chemical changes.•Water from the Middle Miocene sandstone indicates dilution and ...ceasing outflow.•Upper Miocene sandy aquifer is being depleted at a drawdown rate of 0.53m/year.•Daily, seasonal, annual and multi-annual hydraulic trends were identified.
The already exploited geothermal resources in the Mura-Zala basin are planned to be further developed. In this study I investigated thermal water abstraction and its impact on both the fissured basement aquifers and the intergranular Neogene siliciclastic aquifers. Total abstraction of thermal water in north-east Slovenia summed to 3.1millionm3 in 2011, with very limited artificial recharge supplied through a single reinjection well. This exploitation has resulted in depletion of the aquifers, with decline in aquifer pressure, piezometric groundwater levels and discharge rates, as well as chemistry variation, being evident in many wells. A research monitoring network has been established in 2009 and has been taking hourly measurements in eight wells. These wells are up to 2km deep and tap aquifers in the Upper Miocene sandy Mura Formation. Daily, seasonal and annual trends were interpreted, and the measured overall regionally declining static groundwater levels are alarming, reaching 0.53m per year. Despite the changes in conditions in the aquifers, no change of production temperature has so far been perceived.
Many hollows defined as pit houses are known from the Neo-Eneolithic period. Similar pits were also detected at the Neo-Eneolithic settlement of Zgornje Radvanje. The cluster of pits presented in ...this paper shows a stratigraphic sequence. One of the phases yielded a structure. Pottery forms, production and decoration are presented for each individual phase. A comparison of pottery forms and decoration with other sites indicates that the earliest pottery assemblages originate from the late Neolithic period.
Hydraulic conductivities (K) can be obtainedfrom pumping and slug tests as well as grain size analysis.Although empirical methods for such estimations are longstanding,there is still insufficient ...comparison of K valuesamong the various approaches. Six grain-size analysismethods were tested on coarse-grained alluvial sedimentsfrom 12 water wells in NE Slovenia. Values of K from grainsizemethods were compared to those of pumping testsand slug tests. Six grain-size methods (USBR, Slichter,Hazen, Beyer, Kozeny-Carman, and Terzaghi) were usedfor comparison with the Theis and Neuman pumping testmethod and the Bouwer-Rice method for slug tests. Theresults show that the USBR (US Bureau of Reclamation)method overestimates K values and there is no correlationwith other results, so its use is not advised. Conversely,whilst the Slichter method gives much lower estimatesof K, it is the only one to completely fulfill the grainsize requirements. Other methods (Hazen, Beyer, Kozeny-Carman, and Terzaghi) result in intermediate values andare similar to the Slichter method; however they should beused for smaller-sized sediments. Due to their high transmissivityand small radius of inffiuence, slug tests shouldbe avoided in the analysis of gravels, as they only test asmall portion of the aquifer compared to pumping tests.This is confirmed by the low correlation coefficients betweenhydraulic conductivities obtained from pumpingtests and slug tests.
The Mura-Zala sedimentary Basin is a Neogene basin with many competing geopotentials, spanning parts of Slovenia, Austria, Croatia and Hungary. Here we present the 3D regional geological model of the ...Slovenian part of the Mura-Zala Basin, which was developed to integrate the latest information on the geological structure of NE Slovenia and to publish the model in an open-access mode for easier and faster assessment of geopotentials. This was achieved through the harmonisation of the legacy geological models, the reinterpretation of 145 borehole logs, the construction of the 3D numerical geological model in JewelSuiteTM, and delivering it into a 3D-Explorer environment. The model comprises nine lithostratigraphical units. The Pre-Neogene basement rocks are covered by the Haloze Formation; the Špilje Formation – Badenian and Sarmatian; the Lendava Formation – turbidites and slope; the Mura Formation – delta front and delta plain; and the alluvial Ptuj-Grad Formation. The model has two principal shortcomings, related to currently unavailable seismic reflction data faults were not implemented, and the Quaternary formations were not delimited. The model is useful for regional-scale studies and may reduce geological risks related to exploration in NE Slovenia. It will also support a better assessment of geopotentials and a more feasible approach to their development, and, eventually, will enable the harmonized management of our subsurface in 3D space. This can be achieved using the 3D-Explorer platform which enables the creation of arbitrary vertical cross-sections, horizontal slices and virtual boreholes.
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