Knowledge of the hydraulic and geological properties of karst systems is particularly valuable to hydrogeologists because these systems represent an important source of potable water in many ...countries. However, the high heterogeneity that characterizes karst systems complicates the definition of karst hydrogeological properties, and their estimation involves complex and expensive techniques. In this study, a workflow for karst spring characterization was used to analyze two springs, Nanto spring and Mossano spring, located in the Berici Mountains (NE Italy). Based on the data derived from 4 years of continuous hourly monitoring of discharge, water temperature and specific electrical conductivity, a hydrogeological conceptual model for the monitored springs was proposed. Flow rate measurements, which combined recession curve, flow duration curve and autocorrelation function techniques, were used to evaluate the spring discharge variability. Changes in spring discharge can be related both to the degree of karstification/permeability and to the size of the karst aquifer. Moreover, combining monitored parameters and rainfall—analyzed by the cross-correlation function and VESPA (Vulnerability Estimator for Spring Protection Areas) index approach—permitted assessment of the spring response to recharge and the behavior of the drainage system. Although the responses to the recharge events were quite similar, the two springs showed some differences in terms of the degree of karstification. In fact, Mossano spring showed a more developed karst system than Nanto spring. Three systems (two karsts and one matrix/fractured) are outlined for Mossano spring, while two systems (one karst and one matrix/fractured) are outlined for Nanto spring.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Within the Venetian Pre-Alps, the Borcola Pass connects the Posina (Vicenza province) and the Terragnolo (Trento province) valleys. The Posina valley is located north of Schio (Vicenza) within the ...Italian Southern Alps structural unit. In this area, the injection of Paleogene basaltic dykes along fault/fractures in the late Triassic Dolomia Principale unit has produced a local metamorphism of the dolomite rock into a marble characterized by the presence of brucite veins. This marble was studied in the eighteenth century by the famous Italian scientist Giovanni Arduino, who understood its metamorphic origin. In fact, the marble is always associated with sub-vertical basaltic dykes intruded into the carbonate rocks of the Pre-Alps. Arduino performed also chemical experiments on the marble. The reading of the description of the experiments induced later authors (e.g., Maraschini, von Morlot, Mc Kenzie) to infer that Arduino unknowingly discovered the mineral called dolomite. In this work, we propose that the abandoned Borcola Quarry should be nominated as a geosite, to allow its conservation and popularization and to preserve the memory of a probably minor, yet informative step in the long-lived history of the discovery of dolomite. In addition, this site presents other reasons of interest, such as petrography, mineralogy, structural geology, industrial archeology, and eco-geotourism. The proposed geosite is therefore of great importance in terms of its multidisciplinary scientific value, aesthetic appeal, and educational value.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A multidisciplinary study was carried out on an Upper Pleistocene travertine mound (Montirone Hill; Abano Terme, south of Padova, Veneto, Italy) with the aim of developing a comprehensive ...understanding of the processes interacting in structurally controlled thermal springs and the consequent deposition of thermal limestones. The sedimentology, geochemistry, structural characteristics and hydrogeology of the mound, which is associated with the Euganean geothermal field and the related complex structural framework of the Schio‐Vicenza fault system, were investigated. A palaeo‐environmental model of the deposit has been reconstructed clarifying the connection between the travertine deposition and the regional structural setting. Calcium‐rich thermal waters rose from spring orifices (estimated temperature from 54°C to 61°C based on geochemical calculations) and produced a mound made of coalescent shield‐like bodies. The dominant lime‐mudstone facies resulted from the accumulation of lime mud at the bottom of shallow crater‐like basins located on top of stacked cones. Soft sediment deformations affecting the lime mud sediment were most probably produced by the recurrent uprising of gas bubbles. The overlying crystalline crusts were deposited on the flanks of the mound by waters overflowing from the vents with laminar flux. A deep hydrothermal circuit with a long period of water–rock interaction is supported by geochemical analyses. Furthermore, a local extensional regime, enhancing the migration of thermal fluids to the surface, is inferred based on the results of the structural analysis carried out on the fault/fracture mesh that affects the mound. These results corroborate the well‐established relation among travertine deposits, hydrothermal systems and fault systems, and substantiate the structurally controlled conceptual model of the Euganean hydrothermal system, suggesting that both the thermal and the fault systems were active at least since 34 ka.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Fault zones cutting limestones and dolostones represent significant seismogenic sources worldwide. The structure of an exhumed strike-slip fault zone hosted in dolostones, the Borcola Pass Fault Zone ...(BPFZ, Italian Southern Alps), was studied by means of field and microstructural analysis. Ambient conditions of faulting were ca. 1.6–1.7 km and 50 °C. The BPFZ consists of a >80 m wide damage zone cut by three systems of sub-vertical secondary faults striking approximately N–S, E–W and NW–SE. N–S and E–W striking faults reactivated pre-existing Jurassic-Paleogene joints with spacing between 0.2 and 0.5 m, whereas NW–SE striking faults were newly formed during post-Paleogene activity associated with movements along the nearby Schio–Vicenza Line. The core of the BPFZ consists of dolostone fault rock lenses bound by slip zones up to 10 cm thick. Both the principal and secondary slip zones consist of cement-supported dolomitic cataclasites and dolomite-filled veins. Some slip zones contain a sub-centimeter thick “vein-like” cataclastic layer (Layer-A) located immediately beneath the slip surface that truncates another cataclasite below (Layer-B). Detailed microstructural and clast size distribution analysis suggests that Layer-A experienced fluidization (cuspate-lobate boundaries, injection structures, strong grain sorting: D < 1 for clast diameters smaller than 300 μm) possibly related to fast fault slip following seismic ruptures. In light of these observations a conceptual model is proposed for the formation of Layer-A, and the structure of the BPFZ is compared to that of an active seismogenic fault cutting carbonates.
► The Borcola Pass Fault Zone (BPFZ) is a strike-slip fault zone cutting dolomitic host rocks. ► The damage zone of the BPFZ is cut by secondary faults exploiting pre-existing joints. ► Microstructures of dolostone-cutting slip zones suggest coseismic fluidization. ► Structural complexity of the BPFZ is comparable with that of active seismogenic faults cutting carbonates.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
A comprehensive geomorphological and structural mapping of the largest landslides in the central-eastern Southern Alps (NE Italy) is presented. Their occurrence in this Alpine sector is discussed in ...relation with structural geological features (bedding and faults), which are largely conditioned by the Giudicarie and Schio-Vicenza regional fault systems. Tectonic rock damaging here coexists with high relief stored energy and active deformation, which is testified by present seismicity and cumulative earthquake moment release. Based on updated rock failure ages, slope activity is concentrated at 5-3 and 1 ka, as primarily enhanced by climatic and seismic controls. The analysis of predisposing and driving factors poses the question of present and future landslide hazards for these densely inhabited Alpine valleys.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
In this work, we present the geological map of the San Pellegrino pass, inserted in the spectacular scenario of the Dolomiti region (Southern Alps, Italy), at a scale of 1:10.000 and accompanied by ...geological cross-sections. The detailed distinction of lithological thin units allowed to achieve a consistent interpretation of the local structural setting by drawing brittle and ductile Alpine tectonic deformations. The differential deformation and structural styles within the geological map are the result of the different rheological nature of volcanic and sedimentary rocks, as well as of the superimposition of compressional Alpine tectonics over Permo-Mesozoic extensional tectonic phases, and consequent reactivation of inherited structures.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Assessing the renewability of geothermal and hydrogeological resources is a particular requirement for their future preservation. The sustainable exploitation of a geothermal resource for its ...long-term utilization is related to both the water demand and the hydrogeological characteristics of the geothermal field, while its renewability is influenced by the geological and hydrogeological processes that enhance the groundwater flow. Numerical modeling can be successfully used to assess both the impacts of processes occurring in the geothermal system and the renewability of associated resources. However, the reliability of a numerical simulation is influenced by the accuracy of the dataset used to reproduce the geological system. A 3D hydrogeological reconstruction model, rather than a simplified conceptualization of the geological setting, can increase the consistency of the modeling results. In the case of the Euganean Geothermal System (NE Italy), a detailed reconstruction was performed to quantitatively reproduce the hydrogeological elements that allow the development of the geothermal system and to estimate the amount of thermal waters stored in the reservoir. The structural setting of the central Veneto region, in particular the high-angle NNW-trending faults of the Schio-Vicenza Fault System, plays a fundamental role in the existence of the Euganean Geothermal System, permitting hydraulic connection between the recharge area and the exploitation field. In addition, regional- and local-scale faults and fractures favor fluid convection, which represents the main process that warms thermal fluids. Reproducing such a complex geological setting in a 3D model allows improving knowledge about the features that characterize the geothermal system and attaining a solid framework for the construction of a 3D regional numerical model that will be used to assess the renewability of the system.
•Structural control on the development of a geothermal resource•Hydrogeological conceptual model validation•Estimation of groundwater availability by a 3D hydrogeological reconstruction
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The Piani Eterni karst system is one of the longest and deepest caves of Italy situated in the southern sector of the Dolomiti mountain range. The area where the cave was formed displays peculiar ...structural settings confined in a tectonic transpressive corridor between two regional thrusts (Belluno and Valsugana). During Miocene uplift of the range the inheritance of Mesozoic structures led to the formation of a deep and wide upward-branching flower (or palm tree) structure cutting the carbonate sequence and exposing the surrounding surface to karst processes after erosion. The relative lowering of the hydrologic base level, due both to the uplift of the area and then to the carving of deep glacial valleys in the Quaternary, allowed the formation of paleo-phreatic conduits at subsequently deeper levels, interconnected by vadose shafts and canyons.
This work gives a detailed tectonic interpretation of the transpressive structure and picks out the tectonic features most favorable to the karst development. A detailed statistical analysis of the distribution and orientation of the karst conduits was performed using 31km of 3D surveys showing that the development of the cave was strictly guided by a few favorable surfaces of stratigraphic and tectonic origin. These features are known in the literature as inception horizons and tectonic inception features, respectively. Cave levels are usually related to lithologic favorable conditions associated with standings of the paleo-water table. Here we suggest that some tectonic surface geometries could have led to the opening of voids in the active tectonic phase leading to the formation of the original proto-conduit network. Different types of tectonic inception features identified in the cave were described in terms of geometry and kinematics. Tensional fractures, as well as fault plane undulations and flexural slip surfaces between beds, are described as the most favorable tectonic surfaces for the development of the conduits. Finally, we discuss why transpressional settings and related flower structures in soluble rocks can enhance the karst process allowing the formation of huge and deep karst systems.
► We performed a detailed research of a transpressional structure in the Dolomites. ► Spatial analyses have been done on a 3D model of the Piani Eterni Karst System. ► Three main types of tectonic inception features guiding the system were described. ► Karst processes are enhanced in transpressional structures involving soluble rocks.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Renewable natural resources are strategic for reducing greenhouse gas emissions and the human footprint. The renewability of these resources is a crucial aspect that should be evaluated in ...utilization of scenario planning. The renewability of geothermal resources is strictly related to the physical and geological processes that favor water circulation and heating. In the Veneto region (NE Italy), thermal waters of the Euganean Geothermal System are the most profitable regional geothermal resource, and its renewability assessment entails the evaluation of fluid and heat recharge, regional and local geological settings, and physical processes controlling system development. This renewability assessment is aimed at defining both the importance of such components and the resource amount that can be exploited without compromising its future preservation. In the second part of the twentieth century, the Euganean thermal resource was threatened by severe overexploitation that caused a sharp decrease in the potentiometric level of the thermal aquifers. Consequently, regulation for their exploitation is required. In this work, the renewability of the Euganean Geothermal System was assessed using the results from numerical simulations of fluid flow and heat transport. The simulations were based on a detailed hydrogeological reconstruction that reproduced major regional geological heterogeneities through a 3D unstructured mesh, while a heterogeneous permeability field was used to reproduce the local fracturing of the thermal aquifers. The model results highlight the role played by the resolved structural elements, in particular the subsurface high-angle faults of the exploitation field, and by the anomalous regional crustal heat flow affecting the central Veneto region.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We make a thorough review of geological and seismological data on the long-lived Schio-Vicenza Fault System (SVFS) in northern Italy and present for it a geodynamic and seismotectonic interpretation.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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