The Tolmin Basin constitutes the western part of the Slovenian Basin, a large Mesozoic interplatform basin that was bounded to the north by the Julian Carbonate Platform and to the south by the ...Dinaric Carbonate Platform. Today, it is found along the structural boundary between the Southern Alps and the External Dinarides in northwestern Slovenia. After the drowning of the Julian Carbonate Platform, the Tolmin Basin was dominated by pelagic deposits, namely the Toarcian marlstones (Perbla Formation), the Aalenian to lower Tithonian siliceous limestones and radiolarites (Tolmin Formation), and the upper Tithonian to the Berriasian Biancone Limestone Formation. In this study, a basin-scale sedimentary evolution and calpionellid biostratigraphy of the latter is presented. The Biancone Limestone Formation is a calpionellid-bearing pelagic limestone typical of all deepened segments of the Adria microplate in this time interval. It is generally monotonous but shows considerable vertical and lateral variations. The lower boundary with radiolarites is sharp, revealing a pronounced and rapid overturn in pelagic sedimentation. The lower Berriasian slumps indicate a tectonic pulse. Rare beds of resedimented limestones, assigned to the middle Berriasian, are similar in composition to those intercalated in the underlying radiolarites. They thus show that the factors that led to a significant shift in pelagic sedimentation had little or no effect on shallow-marine carbonate production. In the upper Berriasian, an increase in clay content is evident in the formation, which is explained by the uplift and erosion of the propagating thrust belt in the Neotethys area, superimposed by humidification.
In the Slovenian part of the Gulf of Trieste/Trst, submarine springs occur as funnel-shaped depressions in the Holocene sandy-silt marine sediment that forms the seafoor. These springs exhibit both ...elevated temperatures (up to 29.6 °C) and sulphur content. Based on their location, they are divided into three groups: the Izola group (three springs), the Bele skale group (two springs), and the Ronek group (seven springs). Previous investigations linked these springs to the Izola anticline, characterized by its limestone core and fysch limbs, but no detailed explanation was provided. We propose that: A) sulphur groundwater springs from the limestone (karstic aquifer) at the stratigraphic boundary with the fysch and B) springs occur in the nearshore area, where the sedimentary cover of Quaternary deposits is thin enough to be penetrated by spring waters and washed out. According to existing data, the anticline axis is NW-SE directed, and the Izola group lies approximately on the seaward extension of the axis. Therefore, this interpretation fts perfectly for the Izola group, while the Ronek and Bele skale groups are of-axis extensions and require reinterpretation. In order to resolve the micro-locations of the Ronek and Bele skale groups, we conducted a sedimentological logging of the fysch deposits and detailed geological mapping. The investigations revealed that: A) limestone outcrops occur only in the town of Izola, B) two prominent calciturbidite megabeds that occur in the fysch enable very detailed geological mapping, and C) the axis of the Izola anticline is oriented in the WNW-ESE direction, and this moderate anti-clockwise rotation of the anticline axis explains the micro-locations of all springs. The Ronek and Bele skale groups are located on the southern side, and the Izola group is on the northern side of the limestone core of the Izola anticline.
The study area is located in cental Slovenia, and geologically located at the junction between the Alps and the Dinarides. The Middle Triassic of this region is characterised by intense rifting ...manifested by differential subsidence and volcanism. This led to a major paleogeographic reorganisation of the region, where three paleogeographic domains formed in the Upper Triassic: The Julian Carbonate Platform in the north, the intermediate Slovenian Basin, both parts of the Southern Alps, and the Dinaric (Adriatic, Friuli) Carbonate Platform in the south, which today is a part of the External Dinarides that host the area of investigation. Prior to the installation of the Dinaric Carbonate Platfrom, i.e. in the Ladinian, the entire area of the preset-day External Dinarides broke up into numerous tectonic blocks that were exposed to either erosion or continental, shallow-marine, and deep-marine sedimentation. In this study, we analyse at small scale a complex transitional area between a local carbonate platform and the Kobilji curek basin (depositional area dominated by deeper marine sediments), located in the Rute Plateau in central Slovenia south of Ljubljana. During enhanced subsidence, the basin was filled with volcanic material (tuffs and volcanogenic clays and subordinate extrusive material), while the adjacent platform aggraded. The slope was positioned above active paleofaults. During relative sea level lowstand, the platform prograded across the basin. The study area is divided into four major tectonic paleoblocks. The NW paleoblock experienced the most enhanced subsidence, and the platform prograded twice in this area and was submerged again by the rejuvenated subsidence and/or sea-level rise. The second and third paleoblocks subsided only during discrete major subsidence events, and the carbonates of the platform and slope were soon reinstated therein. In the fourth paleoblock to the east the platform persisted during the Ladinian. In the Carnian, the entire study area became emerged, and continental clastics were deposited. These were then replaced by a uniform shallow marine/intertidal Hauptdolomit (Dolomia Principale) formation at the onset of the Norian. This study provides the first detailed reconstruction of the sedimentary evolution of small-scale Ladinian basin and platforms system in the northern External Dinarides.
Tufa samples from 16 consecutive barrages along a 13 km section of the groundwater‐fed Krka River (Slovenia) were analysed for their petrographical, mineralogical, elemental and stable carbon (δ13C) ...and oxygen (δ18O) isotope composition, to establish their relation to current climatic and hydrological conditions. Waters constantly oversaturated with calcite and the steep morphology of the Krka riverbed stimulate rapid CO2 degassing and subsequent tufa precipitation. The carbon isotope fractionation (Δ13C) between dissolved inorganic carbon and tufa in the Krka River evolves towards isotopic equilibrium being controlled by continuous CO2 degassing and tufa precipitation rate downstream. The Δ13C increased from 1·9 to 2·5‰ (VPDB); however, since tufa precipitation rates remain similar downstream, the major controlling factor of carbon isotope exchange is most probably related to the continuous 12CO2 degassing downstream leaving the carbon pool enriched in 13C. In the case of oxygen, the isotope fractionation (Δ18O) was found to be from 1·0 to 2·3‰ (VSMOW) smaller than reported in the literature. The observed discrepancies are due to different precipitation rates of calcite deposits because Krka tufas on cascades grow relatively faster compared to slowly precipitated calcite deposits in cave or stream pools. Due to non‐equilibrium oxygen isotope exchange between Krka tufa and water, the δ18O proxy showed from 1·2 to 8·2°C higher calculated water temperatures compared to measured water temperatures, demonstrating that δ18O proxy‐based temperature equations are not reliable for water temperature calculations of fast‐growing tufa on cascades. Because Mg is bound to the terrigenous dolomite fraction in the Krka tufa samples, the Mg/Ca was also found to be an unreliable temperature proxy yielding over up to 20°C higher calculated water temperatures.
The northern slopes of the Vipava Valley are defined by a thrust front of Mesozoic carbonates over Tertiary flysch deposits. These slopes are characterized by a variety of different surface forms, ...among which recent and fossil polygenetic landslides are the most prominent mass movements. We used the height variability method as a morphometric indicator, which proved to be the most useful among the various methods for quantifying and visualizing fossil landslides. Height variability is based on the difference in elevations derived from a high-resolution lidar-derived DEM. Based on geologic field mapping and geomorphometric analysis, we distinguished two main types of movements: structurally induced movement along the fault zone and movements caused by complex Quaternary gravitational slope processes. The most pronounced element is the sliding of the huge rotational carbonate massif, which was displaced partly along older fault structures in the hinterland of fossil rock avalanches and carbonate blocks. In addition to the material properties of the lithology, the level of surface roughness also depends on the depositional processes of the individual sedimentary bodies. These were formed by complex sedimentary events and are intertwined in the geological past. The sedimentary bodies indicate two large fossil rock avalanches, while the smaller gravity blocks indicate translational–rotational slides of carbonate and carbonate breccia.
The Bay of Koper is influenced by agricultural, urban, and port activities, therefore pollution from trace metals is a concern. A total of 20 sediment samples obtained from four 10-cm sediment cores ...were analyzed. Element concentration in the sediment of the bay was determined spatially and temporally from the recent surface to depth. The results were correlated with the composition and diversity of the benthic foraminiferal assemblages. Major element concentrations indicate natural lithogenic origin (which is also confirmed by mineralogical features). The benthic foraminiferal assemblages in sediment samples, although mainly composed of representatives of the Rotaliida, show moderate to high species diversity and are dominated by the pollution tolerant species
Ammonia pakinsoniana
,
Haynesina
sp.,
Valvulineria bradyana
and the non-keel
Elphidium
sp. and subordinated by
Ammonia tepida
and
Haynesina depressula
. Canonical correspondence analysis (CCA) on foraminiferal species and trace element concentrations shows a possible control of some potential toxic elements (i.e., Cu, Ni, Pb, Zr, Cr, As) on the diversity and taxonomic composition of foraminiferal assemblages. Nevertheless, foraminiferal diversity and dominance in the bay are related to sediment characteristics such as sediment grain size, and the amount of terrigenous inflow rather than to the element concentrations of sediments. This study evaluated ecological conditions by using the Foram-AMBi and EcoQS indices. The values of the Foram-AMBI index reflect the good to moderate quality of ecological conditions, whereas high to poor ecological statuses were interpreted by calculating EcoQS.
The Marof archaeological site, which dates back to the 1st–5th centuries ce, lies 10 km SE of the Roman settlement of Emona of Regio X (Venetia and Histria). In addition to other artefacts, several ...stone blocks were recovered. The blocks include worked (shaped) and unworked (natural forms) objects. The provenance of these stones was determined based on their lithological characteristics. The analysis shows that the stone is of Early Jurassic age. While the worked blocks are lithologically diverse and extracted from several sources located within a 10 km radius, the unworked blocks are lithologically homogeneous and originate from the site.
We present an integrated approach to characterizing the Žvepovnik sulphur spring, comprising detailed basic geological (mapping), geochemical (physico-chemical, elementary), isotopic (δ2H, δ18O, ...δ13CDIC, δ34S and 3H), and microbiological analyses. We used a multi-parameter approach to determine the origin of the water (meteoric or deeper infiltration), the origin of the carbon and sulphur, and water retention times. Our special research interest is the origin of the sulphur, as sulphur springs are rare and insufficiently investigated. Our results show that the Žvepovnik spring occurs along the fault near the contact between the dolomite aquifer and overlying shales and volcanoclastic beds. The spring water is the result of the mixing of (1) deeper waters in contact with gypsum and anhydrite and (2) shallow waters originating from precipitation and flowing through the surface carbonate aquifer. The results of δ2H and δ18O confirm local modern precipitation as the main source of the spring. δ13CDIC originates from the degradation of organic matter and the dissolution of carbonates. We therefore propose four possible sources of sulphur: (1) the most probable is the dissolution of gypsum/anhydrite; (2) barite may be a minor source of sulphur; (3) the microbial dissimilatory sulfate reduction; and (4) the oxidation of pyrite as the least probable option.
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