Chemical and isotopic composition of CO2-rich magnesium- sodium-bicarbonate-sulphate-type mineral waters from volcanoclastic aquifer in Rogaška Slatina, SloveniaTeodóra Szőcs
, Andrej Lapanje
, László Palcsu
, Nina Rman
Abstract: Bottled natural mineral waters from an andesitic aquifer in Slovenia are enriched in magnesium (1.1 g/l), sulphate (2.2 g/l) and dissolved inorganic carbon (204 g/l). We analysed major ions, trace elements, tritium activity, 14 C, d18 OH2O , d2 HH2O, d13 CDIC, gas composition and noble gases in six wells. In addition, 87 Sr/ /86 Sr, d34 SSO4 and d11 B were analysed here for the first time. Stable isotopes with d18 O = -11.97 to -10.30% and d2 H = -77.3 to -63.8 confirm meteoric origin. CO2 degassing is evident at three wells, causing the oxygen shift of about -1.3%. Tritium activity was detectable only in the shallowest well, where the freshwater component was dated to the 1960s. d13 CDIC in five waters is -1.78 to ? 1.33%, typical of carbonate dissolution. Radiocarbon is low, 1.03–5.16 pMC. Chemical correction with bicarbonate concentration and d13 C correction methods gave best mean residence times, slightly longer than previously published. Sulphate has d34 S 26.6–28.9% and d18 O 8.9–11.1% due to dissolution of evaporites in carbonate rocks. Boron at concentrations of 1.2–6.1 mg/l has two origins: d11 B = 11.3–16.4% from hydrothermal alteration and d11 B = 26.6–31.7% from carbonate dissolution. Strontium at concentrations of 0.5–22.0 mg/l has 87 Sr/ /86 Sr, indicating three sources: 0.7106 for Miocene clastic rocks, 0.7082 for Triassic carbonates and 0.7070 for Lower Oligocene andesitic rocks. CO 2 represents the majority of the dissolved ([ 98.84 vol%) and separated gas ([ 95.23 vol%). Methane is only found in two wells with a max. of 0.30 vol%. All waters show excess helium and 16–97% of mantlederived helium. Since all show subsurface degassing, the paleo-infiltration temperature could not be calculated.
Keywords: natural tracers, carbon, sulphur, strontium and boron isotopes, noble gases
DiRROS - Published: 24.03.2022; Views: 109; Downloads: 48
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Characterizing the groundwater flow regime in a landslide recharge area using stable isotopes: a case study of the Urbas landslide area in NW SloveniaMitja Janža
, Luka Serianz
, Katja Koren
Abstract: Slope stability strongly depends on the prevailing hydrological and hydrogeological conditions. The amount and intensity of precipitation and changing groundwater levels are important landslide triggering factors. Environmental tracers, including the chemical and stable isotope compositions of precipitation and groundwater, were used to gain insight into the groundwater dynamics of the Urbas landslide. The landslide is situated in a mountainous area with steep slopes and high precipitation amount and poses a high risk for the safety of the Koroška Bela settlement that lies downstream. The stable isotope analyses of oxygen-18 (18O) and deuterium (2H) in the precipitation and groundwater were used to estimate the groundwater mean residence time and the average altitude of the landslide recharge area. This information will help to plan and prioritize remedial landslide measures aiming to reduce the recharge of the landslide body and, thus, lower the risk of transformation of the sliding material into debris flow. The results of the chemical analysis of samples taken from springs and a piezometer show a Ca–HCO3 water type. This indicates low water–rock interaction in a landslide area composed of Upper Carboniferous and Permian clastic rocks and points to upper laying carbonate rocks and scree deposits as the main recharge area. Water samples for stable isotope analyses of δ18O and δ2H were collected from a rain gauge, springs, and a piezometer over a two-year period (2018–2020). The estimated mean recharge altitude of the groundwater at sampling points was from approximately 1700 to 1800 m a.s.l. with a mean residence time of 2–5 months.
Keywords: landslide, groundwater, stable isotopes, oxygen-18, deuterium, hydrogeology, recharge dynamic
DiRROS - Published: 16.03.2022; Views: 122; Downloads: 50
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Pesticidi v vodonosniku Krško-Brežiškega poljaJanko Urbanc
, Anja Koroša
, Nina Mali
Abstract: Onesnaženje podzemne vode s pesticidi je splošno razširjen problem, tako v svetu kot tudi v Sloveniji. Glede na pretekle velike obremenitve podzemne vode s pesticidi, je bil namen predstavljene raziskave ugotoviti razširjenost pesticidov v podzemni vodi Krško-Brežiškega polja v obdobju 2018 - 2019 in pri tem preveriti uporabnost metode vzorčenja vode s pasivnimi vzorčevalniki. Skupno smo odvzeli 21 vzorcev podzemne vode na enajstih lokacijah in po dva vzorca v rekah Sava in Krka. V vodi smo določili 15 različnih pesticidov in njihovih razgradnih produktov. V vzorcih podzemne vode sta bila največkrat določena atrazin in njegov razgradni produkt desetilatrazin. Sledijo pesticidi desetilterbutilazin, terbutilazin, metolaklor ter simazin. V površinski vodi smo zaznali atrazin, desetilatrazin, klortoluron, metolaklor in terbutilazin. S kvalitativno metodo vzorčenja s pasivnimi vzorčevalniki smo v podzemni in površinski vodi odvzeli skupno 24 vzorcev. Izločili smo 8 pesticidov, ki se pojavljajo v dveh serijah. Pogostnost pojavljanja posameznih pesticidov je po obeh metodah primerljiva. Pasivno vzorčenje vode se je izkazalo za primerno metodo identifikacije prisotnosti pesticidov. Največje obremenitve s pesticidi na Krško-Brežiškem polju prihajajo s kmetijskih površin. Podzemna voda je bolj obremenjena s pesticidi v osrednjem delu polja v smeri toka od zahoda proti vzhodu. Atrazin in desetilatrazin sta še vedno, kljub dvajsetletni prepovedi, najpogosteje in v najvišjih koncentracijah zaznana pesticida v podzemni vodi Krško-Brežiškega polja.
Keywords: podzemna voda, vodonosnik Krško-Brežiško polje, pesticidi
DiRROS - Published: 09.03.2022; Views: 153; Downloads: 55
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Geophysical investigations in the Radovna River Spring area (Julian Alps, NW Slovenia)Mihael Brenčič
, Andrej Gosar
, Jure Atanackov
, Marjana Zajc
, Anja Torkar
Abstract: The Radovna River Valley is located in the north-western part of Slovenia in the Julian Alps, where there is an extensive intergranular aquifer whose depth to pre-Quaternary bedrock is unknown. Therefore, to obtain information about the depth of the valley and the geometry of the aquif er two geophysical methods were used in our study; ground penetrating radar (GPR) and seismic reflection method. The low-frequency GPR method has shown to be useful for determining the depth of the groundwater and the predominant groundwater recharge. Also, the high-resolution seismic method provided an insight about the morphology of the pre-Quaternary basement with the deepest point at 141 meters below surface. Measurements of hydrogeological parameters such as groundwater level and river discharge measurements were carried out in the study area. Both data analyses showed that groundwater level and river discharge are highly fluctuatingand rapidly changing, indicating a well-permeable aquifer, implying that such an aquifer is extremely sensitive and vulnerable to extreme climate events. Both the geophysical methods and the hydrogeological information have provided important information about the morphology of the valley and the alluvial aquifer, as well as increasing the knowledge about the Radovna springs system, which will contribute very important information for future hydrogeological studies.
Keywords: Ground penetrating radar, Seismic reflection method, Radovna spring, hydrogeology, aquifer geometry, glacial valley, groundwater table
DiRROS - Published: 09.03.2022; Views: 133; Downloads: 42
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The Sistiana Fault and the Sistiana Bending Zone (SW Slovenia)Bogomir Celarc
, Petra Jamšek Rupnik
, Ladislav Placer
Abstract: The Sistiana Fault is an alleged disjunctive deformation of Microadria in the sea bottom of the Gulf of Trieste. Onshore, it is visible only in the Sistiana Bay, but towards the northeast it soon pinches-out, in structural-geometric terms it diminishes soon after the crossing of the thrust boundary of the Dinarides, or the Istrian-Friuli Underthrustig Zone, respectively. Further to the northeast, only the bending zone is developed in the External Dinarides, which stretches all the way from the Sistiana Bay to the Idrija-Žiri area. We named it the Sistiana Bending Zone. Its direction can be determined based on geological maps and is around 60°, so we conclude that the Sistiana Fault should extend approximately in this direction. In the bending zone, the Trieste-Komen Anticlinorium, the Vipava Synclinorium, the Trnovo Nappe opposite to the Hrušica Nappe and the Raša and Idrija Faults are laterally bent. The size of the bend is the largest in the Sistiana Bay, and in the east-northeast direction it decreases linearly. The general geological circumstances suggest that the Sistiana Fault has not been recently active.
Keywords: Sistiana Fault, Sistiana Bending Zone, adjusting fault, Adria Microplate, Gulf of Trieste
DiRROS - Published: 09.03.2022; Views: 149; Downloads: 53
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Using stable isotopes and major ions to identify recharge characteristics of the Alpine groundwater-flow dominated Triglavska Bistrica RiverPolona Vreča
, Sonja Cerar
, Luka Serianz
Abstract: Triglavska Bistrica is a typical Alpine river in the north-western part of Slovenia. Its recharge area includes some of the highest peaks in the Julian Alps. The hydrogeological conditions and flow of the river depend largely on groundwater exchange between the karstified aquifer in the carbonate rocks and the intergranular aquifer in the glaciofluvial deposits. The average volume of the river flow is up to several m3/s. In this study, water samples from different locations along the river were analysed for stable isotope ratios of oxygen and hydrogen, major ions, and concentration of tritium activity. The correlation of major ions suggests that the recharge area consists of both limestone and dolomite rocks. The δ18O and δ2H values decrease downstream, implying that the average recharge elevation increases. At the downstream sampling site V-5, located approx. 300 m upstream from the confluence of the Sava Dolinka River, the calculated mean recharge altitude is estimated to be 1,996 m.
Keywords: groundwater, oxygen and hydrogen isotopes, hydrogeochemistry, recharge area, Alpine aquifer, Slovenia
DiRROS - Published: 09.03.2022; Views: 278; Downloads: 51
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Strukturne razmere na stiku Južnih Alp in Dinaridov na zahodnem CerkljanskemBlaž Milanič
, Jernej Jež
, Jože Čar
Abstract: Ozemlje med vasmi Reka v dolini Idrijce, Bukovo pod Kojco in Zakriž pri Cerknem pripada v geografskem in geotektonskem pogledu Dinaridom. Gradijo ga kamnine dveh obsežnih narivnih enot Trnovskega pokrova, ki so bile za več deset kilometrov narinjene od severovzhoda proti jugozahodu v današnjo lego. Preko njih so narinjene kamnine Tolminskega pokrova, ki je na obravnavanem ozemlju najnižja narivna enota Južnih Alp. Pokrov sestavljajo dve notranji narivni grudi in vmesna narivna luska. Narivne enote so bile narinjene od severa proti jugu. V zahodnem delu obravnavanega območja stik med Južnimi Alpami in Dinaridi poteka ob Sovodenjskem prelomu.Kljub temu, da so kamnine v obravnavanih narivnih enotah približno enake starosti, lahko prepoznamo dva različna stratigrafska razvoja. Posebej izstopa problematika razvoja ladinijsko-spodnjekarnijskih psevdoziljskih plasti, to je zaporedja klastičnih in karbonatnih kamnin, ki se je odložilo v globljemorskem okolju Slovenskega bazena. Tako v Trnovskem kot tudi v Tolminskem pokrovu najdemo psevdoziljske plasti razvite v podobnem, litološko značilnem zaporedju, a so v Tolminskem pokrovu razvite v precej večji debelini kot v Trnovskem pokrovu in navzgor zvezno prehajajo v amfiklinske plasti, medtem ko je debelina psevdoziljskih plasti v Trnovskem pokrovu precej manjša, v normalnem zaporedju pa na njih leži platformni cordevolski dolomit.
Keywords: narivna zgradba, Trnovski pokrov, Tolminski pokrov, Južne Alpe, Dinaridi, Slovenski bazen, trias, psevdoziljske plasti
DiRROS - Published: 09.03.2022; Views: 121; Downloads: 48
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Sedimentological and paleontological analysis of the Lower Jurassic part of the Zatrnik Formation on the Pokljuka plateau, SloveniaAnja Vidervol
, Boštjan Rožič
, Duje Kukoč
, Luka Gale
Abstract: The uppermost Ladinian to Lower Jurassic Zatrnik Formation is the lithostratigraphic unit of the Mesozoic deeper marine Bled Basin. The uppermost part of the Zatrnik Formation and the transition into the overlying Ribnica Breccia was logged at the Zajamniki mountain pasture on the Pokljuka mountain plateau in the Julian Alps. The lowermost part the section belongs to the “classical” Zatrnik Formation and is dominated by beige micritic limestone and fine-grained calcarenite. Foraminifers Siphovalvulina, ?Everticyclammina, ?Mesoendothyra and ?Pseudopfenderina are present, indicating Early Jurassic age. The beige limestone is followed by light pink limestone of the uppermost Zatrnik Formation. Slumps are common in this interval, and crinoids are abundant. Alongside some species already present in beds lower in the succession, Meandrovoluta asiagoensis Fugagnoli & Rettori, Trocholina sp., Valvulinidae, small Textulariidae, Lagenida, and small ?Ophthalmidium alsooccur in this interval. Resedimented limestone predominates through the studied part of the Zatrnik Formation, indicating deposition on the slope or at the foot of the slope of the basin. The switch to crinoid-rich facies within the slumped interval of the Zatrnik Formation may reflect accelerated subsidence of the margins of the Julian Carbonate Platform in the Pliensbachian. The Zatrnik Formation is followed by the formation of the Pliensbachian (?) Ribnica Breccia. Impregnations of ferromanganese oxides, violet colour, and an increase in clay content are characteristic. The foraminiferal assemblage consists of Lenticulina, small elongated Lagenida, and epistominids. Individual beds of the Ribnica Breccia were deposited via debris flows. Enrichments in ferromanganese oxides point to slower sedimentation.
Keywords: Lower Jurassic, Bled Basin, Pokljuka Nappe, stratigraphy, foraminifer, Hierlatz facies, Ribnica Breccia, Zajamniki
DiRROS - Published: 09.03.2022; Views: 118; Downloads: 47
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Impact of climate change on landslides in Slovenia in the mid-21st centuryJernej Jež
, Mojca Dolinar
, Anže Medved
, Špela Kumelj
, Gašper Bokal
, Mateja Jemec Auflič
Abstract: Slovenia is affected by extreme and intense rainfall that triggers numerous landslides every year, resulting in significant human impact and damage to infrastructure. Previous studies on landslides have shown how rainfall patterns can influence landslide occurrence, while in this paper, we present one of the first study in Slovenia to examine the impact of climate change on landslides in the mid-21st century. To do this, we used the Representative Concentration Pathway (RCP) 4.5 climate scenario and future climatology simulated by six climate models that differed from each other as much as possible while representing measured values of past climate variables as closely as possible. Based on baseline period (1981-2010) we showed the number of days with exceedance of rainfall thresholds and the area where landslides may occur more frequently in the projection period (2041-2070). We found that extreme rainfall events are likely to occur more frequent in the future, which may lead to a higher frequency of landslides in some areas.
Keywords: climate change, landslides, models, hazard, prediction
DiRROS - Published: 09.03.2022; Views: 144; Downloads: 42
Fulltext (4,78 MB)
New data on lower Permian rugose corals from the Southern Karavanke Mountains (Slovenia)Dieter Weyer
, Olga L. Kossovaya
, Matevž Novak
Abstract: Studies of upper Palaeozoic corals from the Southern Alps (Karavanke Mountains in Slovenia and Carnic Alps along the Austrian/Italian border) started at the end of the 19th century. Since the mid-20th century, corals of the Karavanke Mountains have been studied in detail by several authors. Recently, several coral type localities and the coral groups occurring therein have been einvestigated. This paper deals in particular with the study of Carinthiaphyllum Heritsch, 1936 and all previously known data have been revised within this study. Most specimens of Carinthiaphyllum originate from museum collections and from new findings in the Dovžanova Soteska area of northern Slovenia. Additional material is represented by newly found samples from the locality of Mt. Boč in eastern Slovenia. The stratigraphic position and age of the Carinthiaphyllum occurrences are determined by fusulinid and conodont assemblages. Two species, Carinthiaphyllum crasseseptatum Gräf & Ramovš, 1965 and C. ramovsi n. sp., are described herein. New morphological features, including root-like protrusions and connecting stereoplasmic tubes, have been found for the first time in gregaria growth mode. Therefore, these new observations provide evidence of a solitary gregaria growth mode: individuals are invariably separated with contact and reciprocal support only by root-like, sometimes channeled tubes occurring as outgrowths of the archaeothecal wall. An emended diagnosis of Carinthiaphyllum is proposed herein. The studied collection is housed in the Museum für Naturkunde (Leibniz-Institut) at the Humboldt University in Berlin.
Keywords: Gregaria corals, Carinthiaphyllum, Asselian-Sakmarian, Southern Alps
DiRROS - Published: 04.03.2022; Views: 111; Downloads: 38
Fulltext (7,42 MB)