Sedimentological and paleontological analysis of the Lower Jurassic part of the Zatrnik Formation on the Pokljuka plateau, Slovenia

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.

Prevalence of pesticides in Krško-Brežice polje aquifer

Groundwater pollution with pesticides is a problem that occurs all over the world as well as in Slovenia. Considering the past high loads of groundwater with pesticides, the purpose of the presented research was to determine the presence of pesticides in the groundwater of Krško-Brežiško polje in the period 2018-2019 and to check the applicability of the passive sampling method. A total of 21 groundwater samples were taken at 11 locations and 2 samples each in the Sava and Krka rivers. We identified 15 pesticides and their degradation products. Atrazine and its degradation product desethylatrazine were most frequently determined in groundwater samples. They are followed by desethylterbutylazine, terbutylazine, metolachlor and simazine. Atrazine, desethylatrazine, chlortoluron, metolachlor and terbuthylazine were detected in surface water. A total of 24 samples were taken in groundwater and surface water using the qualitative passive sampling method. We singled out 8 pesticides that appear in two campaigns. The frequency and occurrence of individual pesticides by both methods are comparable. Passive sampling has proven to be an appropriate method of identifying the presence of pesticides. The highest loads in the Krško-Brežiško field arise from the agricultural land areas. Groundwater is more contaminated with pesticides in the central part of the field in the direction of groundwater flow from west to east. In the groundwater of the Krško-Brežice field, atrazine and desethylatrazine are still the most frequently detected pesticides with higher concentrations, despite a 20 years long ban on the use of atrazine-based plant protection products.

The role of the pre-Alpine polycrystalline basement in the paleogeographic configuration of multiple Neotethyan oceanic basins

The study provides a deeper understanding of the early Mesozoic paleogeogeographic spatial-temporal relationship by studying the two Adria-Europe intervening basement blocks. The Drina-Ivanjica and Pelagonian crustal fragments play important role in the internal early Alpine oceanic constitution further controlling the late Jurassic emplacement of Tethyan Dinaric-Hellenic ophiolites. The proposed paleogeographic reassessment is driven by the new paleocontinental inheritance data associated with the Variscan – pre-Variscan basement terranes. The recently published data suggest an Avalonian-type inheritance of the Pelagonian basement block which indicates a different pre-Variscan plate-tectonic journey, including separate spatial arrangement during Variscan amalgamation. In turn, Cadomian-type basement inheritance has been documented within the sliced Adria microplate. Thus, the Avalonian inheritance place the Pelagonian block away from the Apulia/Adria (Dinarides). In the investigated context of Paleozoic-Mesozoic paleogeographic transition, the Pelagonian block may represent a segment of the Cimmerian ribbon continent or southernmost segment of the Variscan Europe. With regards the nearby Adria microplate, a Triassic-Jurassic oceanic opening led to the decoupling (spreading away from the main Adria microplate) of the Drina-Ivanjica block. The rifting is in line with the simultaneous yet opposite or westward-directed drift of the Pelagonides. The breakup of south European Variscan configuration eventually result in the spatial alignment of the two basement fragments referred to as the “Drina–Pelagonide continental splinter”. By linking the paleogeographic pre-Jurassic–Jurassic relationship between these continental units, the two landlocked Neotethyan Vardar s.l. basins are extrapolated, “Dinaric Tethys” / Inner Dinaric-(Mirdita-Pindos) and the main Vardar Ocean (Western Vardar Zone).

The Sistiana Fault and the Sistiana Bending Zone (SW Slovenia)

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.

Structural setting at the contact of the Southern Alps and Dinarides in western Cerkljansko region (western Slovenia)

The area between the villages of Reka in the Idrijca Valley, Bukovo and Zakriž near Cerkno belongs geographically and geotectonically to the Dinarides. The area consists of two large inner thrust blocks of the Trnovo nappe, which were thrusted for tens of kilometers in the direction of SW to their present position. They are overlain by the Tolmin nappe, the lowest thrust unit of the Southern Alps. The Tolmin nappe was thrusted from N to S and consists of two inner thrust blocks and a smaller intermediate inner sheet. In the western part of the area the contact between Southern Alps and the Dinarides runs along the regional Sovodenj fault.Although the rocks in the considered thrust units are about the same age, different stratigraphic settings could be recognized. The lithostratigraphic features of the Ladinian-Lower Carnian Pseudizilian beds are particularly striking. Succession of clastic and carbonate rocks was deposited in deep-marine Slovenian basin. In both the Trnovo and Tolmin nappe, Pseudozilian beds occur in the lithologically characteristic sequences but, in the Tolmin nappe, they are developed in a much greater thickness than in the Trnovo nappe and pass continuously upwards into Amphyclina beds, while in the Trnovo nappe, on the other hand, the succession of Pseudozilian beds is much thinner and is overlain by the platform Cordevol dolomite.

Geophysical investigations in the Radovna River Spring area (Julian Alps, NW Slovenia)

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 aquifer 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 fluctuating and 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.

Using stable isotopes and major ions to identify recharge characteristics of the Alpine groundwater-flow dominated Triglavska Bistrica River

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.

Impact of climate change on landslides in Slovenia in the mid-21st century

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.

Tectonics and gravitational phenomena (Nanos, Slovenia)

The Istra Pushed Area is a specifically deformed territory of the northwestern part of the External Dinarides. It formed due to the movement of the Istra block as part of the Adriatic Microplate (Adria) towards the Dinarides since the middle Miocene. The movement of the Istra block caused hereditary shifts along the old dislocations dating back to the early formation stage of the formation of the Dinarides at the end of the Eocene and their deformation. These deformations are reflected also in certain extreme gravitational phenomena along the boundary between the External Dinaric Imbricated Belt and the External Dinaric Thrust Belt, where Mesozoic carbonates are thrusted upon the Cenozoic flysch. The boundary zone between these two belts connects the Trnovo, Hrušica and Snežnik Thrust Fronts. Four specific gravitational phenomena that occurred in this boundary zone are presented here, as they are remarkable in terms of their size: Črna griža (Trnovo Nappe), Suhi vrh (Hrušica Nappe), Petelinje mlake and Ilirska Bistrica (both from the Snežnik Nappe). The phenomena at Suhi vrh is described in detail herein.

West Balkan Mineral Register of Primary Raw Materials

Rational and long-term planning and sustainable mineral resources management is of strategic importance in Europe’s efforts to secure the self-supply of mineral raw materials. European mineral data is organized and accessible within the pan-European Minerals Intelligence Network. Most EU countries are part of this network, while the West Balkan region presents a gap in this regard. A common West Balkan mineral register needs to be established in order to close the gap and bring the area closer to the EU market. Including the region into the network would provide new opportunities to local industry and improve mineral management at the national and regional level. In this context, the Geological Survey of Slovenia is working in cooperation with numerous partners and stakeholders in different projects within the framework of European initiatives and programs. We collected and properly organized relevant data on minerals in the region according to the INSPIRE Directive. This paper describes the creation of the West Balkan Mineral Register of primary raw materials, and its content.