This study presents a comprehensive investigation of the unroofed cave above the active Škocjanske Jame water cave and explains the intricate processes that characterize the karst landscape. Despite ...extensive knowledge of the karst morphology, the precise development stages and timing of formation remained ambiguous. Through detailed multi-proxy sedimentary analyses, we unveil the sedimentary features documenting relict speleogenetic processes and provide insights into regional tectonic events and climatic changes. The cave was filled with two types of sediments: the upper speleothem section and the lower allogenic clastic section. Based on paleomagnetic characteristic and U/Th data, the fill of the unroofed cave is estimated to be between approximately 5 Ma (probably 5.2 to 4.9 Ma) and >773 ka old. Our results reveal a complex interplay of allogenic and autogenic sediments, suggesting a stable catchment over several million years. The dating results indicate deposition in phreatic regime since at least 5 Ma, with the river flowing through the cave until about 2.6 Ma. Our study emphasizes the importance of tectonically-driven uplift phases in cave speleogenesis rather than the importance of Quaternary climate changes. Furthermore, we define the initial stages of the development of the Škocjanske Jame karst system and estimate the time span of the evolution of solution and collapse dolines. This research underscores the importance of integrating geological, hydrological, and chronological approaches to unravel the history of karst landscapes and their implications for understanding dynamic karst processes. The temporal and spatial reconstruction of the development of the unroofed caves provides an insight into the first stages of the present karst system influenced by the sinking river.
•Sedimentation changes due to multiple tectonic regional uplifts since the Pliocene.•Early stage of Škocjanske Jame as an unroofed cave above the active cave•Allogenic sediments deposited between 5 and 2.6 Ma.•The last time the river flowed through the cave was approximately 2.6 Ma.•Unroofing of the cave (denudation) occurred within the last 0.6 Ma.
A flowstone section in the Račiška pečina Cave (Classical Karst, SW Slovenia) records multiple chronostratigraphic and palaeoclimatic proxies that can be correlated with other records on the global ...scale (Mediterranean region, Japan). Its upper part has an excellent record of the Matuyama/Brunhes (M/B) magnetic reversal. The M/B reversal zone, which is 6 mm in thickness, was detected by a high-resolution palaeomagnetic analysis of the sequence. An age model based on oxygen isotopic stratigraphy locates this quick transition in mid-MIS 19, between 777.9 and 777.2 ka, with the midpoint at 777.7 ka. The transition is marked by abrupt changes in stable isotopic compositions, trace element concentrations and flowstone fabrics that point to temperature and precipitation changes. Two distinct maxima in trace element concentrations at the beginning and the end of the M/B transition indicate two periods of higher precipitation, with increased washes of clay minerals into the cave. In addition, the stable isotopic (δ13C and δ18O) compositions indicate that significant cooling and high precipitation occurred during the M/B reversal within the generally warm MIS 19.
Grapevines are being challenged by climate changes, forcing winemakers to implement irrigation systems to cope with excessive water stress. Previous studies focused on a small set of international ...varieties, and only few data are available for terroirs hosting cultivars with possibly different responses to drought stress. In this light, we monitored grapevine water status and grape’s physical and chemical composition, as well as concentration and structural characteristics of grape extractable polyphenols, in ten different Refošk vineyards located in the Classical Karst terroir during 2018 and 2019. Grapevines did not suffer severe stress during the two years, but their response to water shortage periods was highly heterogeneous, as pre-dawn (Ψpd) and minimum (Ψmin) leaf water potential significantly differed between vineyards, especially during the drier part of the season. Moreover, the timing of maximum water stress differed in the two years, as in 2019 longer water shortage periods and higher temperature occurred at flowering stage and before veraison, while in 2018 they were higher after veraison. These differences influenced berry’s quality, as titratable and malic acid concentration in juice, as well as total anthocyanin, total polyphenols and higher high molecular weight proanthocyanidins (HMWP) concentration in skins, were higher in 2019 than in 2018. Regarding seed proanthocyanidins, HMWP concentration, mean degree of polymerisation (mDP) and percentage of galloylation (G) in seeds were higher in 2018 than in 2019. The differences in water status measured in spatially close-related vineyards strongly support the importance of monitoring grapevines’ water status dynamics to design adequate and effective water management activities rather than relying on climate data solely. Moreover, the timing of water shortage periods also played a role in determining Refošk grape quality. Our analyses showed that the higher (but still moderate, with Ψpd and Ψmin mean values around −0.50 and −1.25 MPa, respectively) water stress between veraison and harvest occurred in 2018 might reduce Refošk grape acidity and increase concentration, polymerisation and galloylation of seed extractable proanthocyanidins.
•Climate change is forcing winemakers to implement irrigation systems in Karst.•Water status affects grape quality, but this relationship is poorly understood.•High heterogeneity in water status was found in spatially closed vineyards.•Different timing of water shortage in 2018 and 2019 influenced berry’s quality.•Water management activities should be planned based on actual plant water needs.
The paper aims to present the geology of the western part of the Classical Karst (NW Dinarides), located at the border between Slovenia and Italy. The work is based on archive, published and new data ...collected by Slovenian and Italian researchers within several scientific national and Cross Border Cooperation projects. The map, produced at a scale of 1:50,000, summarizes the lithological and structural setting and is supplemented by three geological cross-sections of the study area.
A 13-month monitoring was carried out in two caves that open up in the north-western sector of the Classical Karst (Gorizia Karst): Antro Casali Neri and Grotta Due Piani. In both, ß + γ ...radioactivity, radon and CO2 have a seasonal pattern, with maximums in summer and minimums in winter, even if their trends are somewhat different, due to the different morphological and thermal conditions. The increases begin when the outside temperature becomes higher than that of the caves and vice versa, decrease is recorded when outside temperature is below the cave temperature. The more modest daily variations of radon, on the other hand, are evident when its concentration is low. Sometimes they are related to meteorological variations or day/night rhythms, but, in other cases, they have no clearly identifiable causes. In Casali Neri cave the maximum radon activity was 50161 Bq/m3, while the CO2 concentration went off the instrument's scale (> 9999 ppm) only in the first days of August 2021. The highest radioactivity value was also recorded in this cave with 0.85 μSv/h (average of 8 minutes of recording), with peaks up to 1.05 μSv/h. In Due Piani cave, on the other hand, the radon activity was lower, with a maximum of 22138 Bq/m3, however, the CO2 values went off the scale from July to the first days of October 2021. In both cases, in the warm months, radon and CO2 appear to come mainly from the fractured rock of epikarstic zone. Further accumulations can then form in points with poor ventilation. Furthermore, research has shown that high concentrations of these two gases are not only typical of large or deep caves, but also of modest and easily accessible caves.
•Karst areas need to be managed in an appropriate and careful manner.•A critical overview of current protection legislation in Slovenia has been prepared.•A new comprehensive management approach for ...karst areas and resources has been proposed.•It provides general, non-prescriptive guidelines for addressing challenges of karst protection.•It is principally based on the enforcement of karst-specific detailed management plans.
Karst terrain offers a great range of economic assets, provides unique habitats and valuable ecosystem services. Owing to its particular nature, this environment is highly susceptible to destruction. Any interference is likely to have irreversible impacts and disturb the natural balance of the elements (water, soil, flora and fauna) and processes (e.g. corrosion, CO2 sequestration, speleothem growth) that constitute it. Karst areas must therefore be holistically managed in an appropriate and careful manner. A critical overview of current protection legislation in Slovenia has been prepared, with particular reference to karst areas. The major problem is a lack of harmonised multi-sector policies regulating land use and planning throughout the karst region, the absence of detailed guidelines and insufficient pursuance of karst in all its complexity and vulnerability. A comprehensive management approach for karst areas has been proposed and could subsequently be adopted by other karst-rich countries. Management is based on the enforcement of karst-specific legislation, including provision of detailed management plans and their strict implementation. Common database maintenance, reconciliation between various stakeholders and raising public awareness are additional important parts of the approach.
The study of the different hydrogeological compartments is a prerequisite for understanding and monitoring different fluxes, thereby evaluating the environmental changes in an ecosystem where ...anthropogenic disturbances are present in order to preserve the most vulnerable groundwaters from contamination and degradation. In many karst domains in the Mediterranean, areas groundwaters and surface waters are a single system, as a result of the features that facilitate the ingression of waters from surface to subsurface. This is also the case for the Classical Karst hydrostructure, which is a carbonate plateau that rises above the northern Adriatic Sea, shared between Italy and Slovenia. The main suppliers to the aquifer are the effective precipitations and the waters from three different rivers: Reka/Timavo, Soča/Isonzo and Vipava/Vipacco. Past and ongoing hydrogeological studies on the area have focused on the connections within the Classical Karst Region aquifer system through the analysis of water caves and springs hydrographs and chemographs. In this paper, the authors present new combined data from major ions, oxygen, hydrogen and strontium stable and radiogenic isotopes which have allowed a more complementary knowledge of the groundwater circulation, provenance and water-rock interactions. All the actions occurred in the framework of the European project HYDROKARST.
After the 1st May 2004, when new countries joined the European Union, the need was felt to link these states through an infrastructure network of motorway and railway links (high speed—HS/high ...capacity—HC) easily able to transport all possible goods throughout Europe. Within this framework, 14 different projects were developed with the aim of linking important cities. One of these links is the Corridor V connecting Lisbon (Portugal) to Kiev (Ukraine) and assigning a strategic role to Italy with respect to the integration process of these countries. In detail, part of the Corridor V is expected to start from Venice, reaching Trieste and from here on to Ljubljana (Slovenia) before proceeding to Budapest and finally reaching Kiev in Ukraine. The whole development (from Portugal to Ukraine) is approximately 4,000 km long of which, about 30 km (less than 1 % of the entire route), falls within the Italian Classical Karst area, a highly karstified zone, renowned worldwide as one of the best karst landscapes on the planet. The present paper regards the GIS statistical methodological approach used to identify the degree of karstification of the Italian Classical Karst providing the stakeholders all the necessary information while planning possible railway HS/HC solutions.
A comparison among lowering rates collected in the limestones of the northeastern Adriatic Region (Italy and Croatia) gives a picture of the erosion patterns in the inland and coastal Classical Karst ...and Istrian Karst. Erosion rates were measured using either a micro-erosion meter or a traversing micro-erosion meter. Beginning from a large dataset spread over a maximum of 26 years, significant differences in limestone lowering rates have been recognized in the surveyed area: the mean lowering rate for the inland Classical Karst area is 0.018 mm/yr whereas in the inland Istrian Karst it is 0.009 mm/yr. In the coastal sectors, the mean erosion rate varies between 0.14 mm/yr in the Gulf of Trieste and 0.04 mm/yr in the sites located along the Istrian shoreline. These differences are probably due to the climatic setting of the Classical Karst area (Mediterranean Continental to Sub-alpine climate) and Istrian Peninsula (Mediterranean climate). Moreover, along the coasts of the Gulf of Trieste there are many submarine springs which are absent along the Istrian coast. It is hypothesized that these underwater springs stress the effect of rainfall along the coast, which is both direct (rain on the measurement site) and mainly indirect (freshwater outflow from submarine springs). Higher lowering rates were surveyed during autumn; rainfall, therefore also freshwater outflow from submarine springs, is particularly high at the end of the summer and in autumn.
Tracer tests are a widely used research method in karst hydrology. In the Classical Karst area on the border between Slovenia and Italy, they have a long history and for the most part they have been ...used to research the underground flow in the main karst conduits between the ponors and the springs. The results of the tracer test from 2013 presented in the article revealed new knowledge about the central part of the aquifer, less well researched to date, where the density of caves and the level of karstification are lower. Two tracers (uranine and amidorhodamine G) were used at two injection points (a research borehole in the central part of the aquifer and the karst surface at a distance of 2.5 km from a drinking water pumping station), and six springs, a pumping station, three boreholes and four karst caves were observed for tracer breakthrough for a full year after injection. The results were compared with findings from three other selected older tracer tests in which uranine was likewise used as a tracer but where hydrological conditions varied (very low, low and medium water levels), as did the methods of injecting tracer (in a sinking stream, in a fracture on the karst surface). The comparison showed how different modes of aquifer recharge and the heterogeneity of aquifer structure affect the characteristics of water flow and solute transport in complex karst aquifers.
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