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Povzetek: Foraminiferal assemblages and proportions of foraminiferal morphogroups were determined from Upper Triassic deposits of the Eiberg Basin and the Hallstatt Zone of the Northern Calcareous Alps in Austria (Eastern Alps). Foraminifera were hand-picked from the residue of marl samples taken from the upper Norian Pötschenkalk Formation, the middle–upper Rhaetian Zlambach Formation, and the uppermost Rhaetian Tiefengraben Member of the Kendlbach Formation. In total, 72 species from 31 genera were determined. Foraminiferal assemblages from the Pötschenkalk Formation at the Thälerergraben section are relatively diverse.Dentalina, Ammodiscus, Nodosaria, and Glomospirella dominate. Foraminiferal assemblages from the Zlambach Formation at the Rossmoos-/Stambachgraben section are also abundant and diverse. The most common foraminifera are Reophax, Dentalina, and Annulina. The uppermost Kössen Formation at the Schlossgraben section is dominated by hyaline taxa. The most common genera are Ichthyolaria, Lenticulina, and Nodosaria. At the Fonsjoch section, the uppermost Kössen Formation contains Lenticulina, Astacolus, and Trochammina. An increase in opportunists suggests variations in oxygen levels during the deposition of the uppermost Kössen Formation. The Kendlbach Formation at the Schlossgraben section is dominated by Lagenida over agglutinated taxa. Astacolus, Lenticulina, and Trochammina are the most common genera. At the Fonsjoch section, the Kendlbach Formation contains mostly Ast acolus, followed by Trochammina, Ammobaculites, Reophax, and Lenticulina. Increases in opportunists point to increased stressful conditions. An increase in nodosariid foraminifera higher up the section indicates a return to better oxygenated conditions.
Ključne besede: Upper Triassic, Pötschenkalk, Zlambach Formation, Kössen Formation, Kendlbach Formation, morphogroup
Objavljeno v DiRROS: 06.07.2026; Ogledov: 58; Prenosov: 62
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Povzetek: The Tithonian–Berriasian Chia Gara Formation in Central Iraq represents a major breakthrough in shale oil exploration. This study investigates two continuous core sections (140m and 137m) from the East Baghdad (EB1) and Balad (Ba1) oilfields, located within the intrashelf basin along the passive margin of the Arabian Plate. Comprehensive geochemical analyses, including major and trace elements, Mo isotopes, and total organic carbon (TOC), were conducted to evaluate the mechanisms controlling organic matter enrichment. The EB1 and Ba1 cores are subdivided into five and four organic sedimentary facies (OSF), respectively. In EB1, TOC values in the lower OSF 1 and OSF2 range from 3.55 to 8.0 wt.% and 2.31 to 4.42wt.% and are higher than those of the upper OSF 3, OSF 4, and OSF 5 that range from 0.5 to 3.77wt. %. In Ba1, OSF 3 and OSF 5, which range from 0.39 to 2.7wt.%. Redox indicators such as U/Th, Ni/Co, EF(U), and EF(Mo) show a progressive shift towards more oxic bottom-water conditions. The δ98/95Mo data (–0.3 to 2.5‰) confirm the presence of euxinic conditions, particularly within OSF2 in both EB1 and Ba1, thereby resolving previous uncertainties regarding bottom-water redox conditions. Primary productivity indices (Cu/Al and Ni/Al ratios) suggest relatively low productivity in deep-water slope and basinal facies. Furthermore, the upwelling indicators (EF(Co) × EF(Mn)), varying from 0 to 0.48 for EB1 and 0.05 to 0.18 for Ba1, suggest that preservation conditions played a more significant role than productivity conditions within the deep-water slope and basin. Differential subsidence, with local uplifts and erosion within the Mesopotamian Foredeep Basin likely contributed to spatial variability in organic enrichment. Overall, this study highlights the importance of the redox environment in the development of high-quality hydrocarbon source rocks in unrestricted environments that present upwelling.
Ključne besede: Mo isotopes, redox conditions, organic matter, primary productivity, geochemical methods, Upper Jurassic–Early Cretaceous, Mesopotamian Basin
Objavljeno v DiRROS: 06.07.2026; Ogledov: 66; Prenosov: 45
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Povzetek: Environmental geophysical investigations require controlled laboratory experiments to better understand the relationships between the parameters measured in the field and complex physicochemical processes occurring in the subsurface. In this work, we introduce the Geoelectrical Laboratory (GEL) of the Geological Survey of Slovenia. A typical application of the spectral induced polarization (SIP) method, focussing on the detection of electron-conducting minerals disseminated in geologic material is presented. This is demonstrated by the close relationship between the polarization peak values (�′′�), and chargeability values associated with the second peak (�2) of polarization spectra estimated from a double Cole-Cole fit, and the metal content, either by the mass % concentration of the ore mineral or the chemical composition (Pb, Zn and Fe) estimated by XRF measurements. We illustrate this for synthetic mixtures of quartz sand and pure Pb-Zn ore particles from the Mežica mine (Slovenia), the Mežica Pb-Zn mine waste material (K-material) and sediments collected from streams near the waste deposits (S-material). These results evidence promising capabilities of the SIP method for in-situ detection of metallic particles, both within the mine waste deposits and sediments in the surrounding areas. However, further SIP investigations are needed in a larger number of material samples along with geochemical, mineralogical, and granulometric data to refine the links of polarization and chargeability to both the mass content of ore and the specific geochemical composition of the materials under investigation, as well as to determine the inf luence of the natural geological materials that constitute both the host rock of Pb-Zn ore and the surrounding sediments (e.g., carbonates).
Ključne besede: induced polarization, chargeability, mine waste, sediments, Mežica, Slovenia
Objavljeno v DiRROS: 06.07.2026; Ogledov: 82; Prenosov: 43
Celotno besedilo (10,98 MB)

Povzetek: Small decentralized water supply systems are often sensitive to local pollution and require a clear understanding of recharge conditions and the hydrodynamics within the water resource catchment. This study develops a conceptual hydrogeological model for the Šmarna Gora area based on geological mapping, long-term monitoring of chemical parameters, and stable isotope analyses (δ18O, δ2H) of precipitation and groundwater. The study was initiated in response to rising pollutant concentrations in the drinking water. Estimates of transit time (TT) and mean residence time (MRT) were used to characterize recharge, mixing processes, and differences between the SG and ZAVRH wells, the existing and alternative water supply wells. Isotope data show that the aquifer is predominantly recharged during colder periods and that Mediterranean air masses have become an increasingly important source of precipitation, suggesting a shift in precipitation patterns. The results indicate that SG has longer TT (6–8 months) and MRT (up to 1–2 years). In contrast, ZAVRH shows shorter TT and MRT (4–6 months), and lower pollutant concentrations. The hydrogeological regime in the catchment of the ZAVRH well is characterized by a dynamic, fast-flowing system with limited storage and more intensive dilution of contaminants by infiltrating water, whereas the catchment of the SG well functions as a deeper and more buffered aquifer with prolonged groundwater residence and a more direct hydraulic linkage to the contaminant source. The findings distinguish two hydrogeological regimes and provide a basis for planning water supply solutions and protection measures.
Ključne besede: stable isotopes, groundwater recharge, mean residence time, transit time, precipitation pattern change, dolomite aquifer, decentralized water supply
Objavljeno v DiRROS: 24.06.2026; Ogledov: 111; Prenosov: 89
Celotno besedilo (2,35 MB)
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Povzetek: In situ measurements of ambient dose equivalent rates were conducted across the territory of Macedonia at five-year intervals in 2010, 2015, and 2020. Data were collected from 68 uniformly distributed locations in 2010 and from 72 locations in both 2015 and 2020, ensuring representative spatial coverage. The main objective of this study was to establish a baseline dataset of outdoor gamma dose rates, evaluate their potential temporal variations, and identify the dominant factors influencing their spatial variability. The results indicate a high degree of temporal stability over the investigated decade, with mean values of 113 nSv/h in 2010 and 110 nSv/h in both 2015 and 2020. Following descriptive statistical analysis, spatial distribution maps were created, revealing that the observed dose rate variability is primarily associated with the country’s diverse geology rather than anthropogenic sources. These findings confirm the reliability of direct in situ monitoring and provide a robust reference framework for assessing environmental and atmospheric contributions to external gamma radiation exposure in Macedonia.
Ključne besede: in situ measurements, ambient dose equivalent rates, long-term monitoring, geological background, Macedonia
Objavljeno v DiRROS: 01.04.2026; Ogledov: 330; Prenosov: 124
Celotno besedilo (5,88 MB)