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Iskalni niz: "polno besedilo" AND "organizacija" (Geološki zavod Slovenije) .

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21.
Geološka spremljava poskusnega odkopa uranove rude na Žirovskem vrhu
Franc Čadež, 2023, strokovni članek

Povzetek: Leta 1981–1983 je bilo na Rudniku Žirovski vrh pred pričetkom redne proizvodnje izvedeno poskusno odkopavanje uranove rude za preverjanje metod geološke in radiometrične kontrole ter tehničnih metod pridobivanja. Poskusni odkop je bil v bloku 1, na skrajnem severozahodnem delu rudišča v zgornji gubi dvojne S strukture. V tem bloku se je orudenje nahajalo samo v horizontu sivega peščenjaka debeline 20–30 m. Z geološko spremljavo odkopavanja smo potrdili, da so bili peščenjaki odloženi v sekvencah debelih od par dm do več kot 2 m. Sekvenca je običajno pričenjala z debelozrnatim peščenjakom, večkrat so bili na bazi prisotni še klasti kremena in muljevca. Navzgor je debelozrnat peščenjak pogosto prehajal v srednjezrnatega, redkeje pa še v drobnozrnatega in meljevec. V peščenjakih je bila značilna prisotnost organskih drobcev, ki so v diagenezi ustvarjali redukcijsko okolje v katerem se je iz podtalnice izločal uran. Najpogosteje se je orudenje nahajalo v debelozrnatih peščenjakih, običajno v debelejših sekvencah. Orudenje se je zato pojavljalo v več nivojih debelih navadno pod 1m, kjer se je združevalo je skupna debelina presegla tudi 5 m. Dolžina sklenjenega orudenja v vzdolžni smeri je znašala do 150 m, širina od nekaj metrov do več kot 40 m. V vmesnih prekinitvah orudenja smo opazovali, da so peščenjaki iz temnosive in sive barve prehajali v svetlosive in zelenosive, ki so bili le siromašno orudeni ali jalovi. V vzdolžni smeri se je tak prehod zgodil med prerezi P-35 in P-35a, kjer se je tudi zaključilo odkopavanje. V jami sta bila raziskana še prereza P-36 in P-37, kjer pa se je pojavljal pretežno zelenosiv peščenjak z le redkimi lečami siromašnega orudenja. S površinskimi vrtinami sta bila dlje proti zahodu raziskana tudi še dva prereza oddaljena 1,3 in 2,8 km od jamske zgradbe. V teh vrtinah je bilo ugotovljeno nastopanje sivih in zelenosivih peščenjakov z zelo redkimi sledovi orudenja, ki so se menjavali z bolj drobnozrnatimi različki (muljevci), ostanki organske snovi pa so bili v njih zelo redki. Blok 1 je bil zato mejni blok na SZ strani rudišča, predviden za pridobivanje.
Ključne besede: uranova ruda, poskusno odkopavanje, grödenske klastične kamnine, Žirovski vrh
Objavljeno v DiRROS: 15.01.2024; Ogledov: 115; Prenosov: 33
.pdf Celotno besedilo (1,80 MB)

22.
Transverse Dinaric zone of increased compression between the Kraški rob and Hrušica Regions, NE Microadria
Ladislav Placer, Igor Rižnar, Ana Novak, 2023, izvirni znanstveni članek

Povzetek: The Kvarner fault divides the Microadria (Adria microplate, the Adria stable core) into the Po and Adria segments. The Istra block, which is sandwiched between the right-lateral Kvarner Fault and the left-lateral Sistiana Fault lies at the extreme eastern edge of the Po segment. Both faults run transversely to the Dinarides and reach their thrust boundary in the east. The Microadria has been moving towards the Dinarides since the Middle Miocene. The movement of the Istra block is exposed in relation to the neighbouring blocks, so an extensive pushed area (the Istra Pushed Area) was formed in the External Dinarides, which is bent towards the northeast. It is defined by two flexural zones, one lying in the extension of the Sistiana Fault and the other in the extension of the Kvarner Fault. The structure of the Dinaric thrust border on the north-eastern side of the Istra block is complex. Its prominent structural element is the Črni Kal Anomaly, due to which a zone of increased compression developed within the Istra Pushed Area and transversely to the Dinarides (Kraški rob – Hrušica Traverse), which lies between the Sistiana and Kvarner Flexural Zones. In terms of kinematics, it differs greatly from these two, and various geomorphologically responsive deformations have occurred within it. Mt. Vremščica (1027 m), which represents a transpressive anticline within the wider zone of the Raša Fault is the most prominent. In order to understand the genesis of the Classical Karst relief, it is important to know that the Mt. Vremščica ridge rose from the levelled karst surface.
Ključne besede: NE Microadria (Adria Microplate), Istra peninsula, Istra Pushed Area, Črni Kal Anomaly, Kraški rob – Mt. Hrušica Traverse, stacked structure, envelope fault
Objavljeno v DiRROS: 15.01.2024; Ogledov: 132; Prenosov: 93
.pdf Celotno besedilo (36,01 MB)

23.
Geochemical and mineralogical approaches in unraveling paleoweathering, provenance, and tectonic setting of the clastic sedimentary succession (Western Central Paratethys)
Kristina Ivančič, Rok Brajkovič, Mirijam Vrabec, 2024, izvirni znanstveni članek

Povzetek: Pronounced tectonic and paleogeographic changes were detected in the Alpine–Pannonian region during the Miocene at the interface between the Alps, the Dinarides, and the Pannonian Basin. To understand the major tectonic, paleogeographic, and paleoclimatic changes during this period, geochemical and mineralogical investigations were carried out on the fine-grained clastic sedimentary rocks in the Tunjice Hills. The paleoweathering indicates a cold and/or arid to a warm and humid period. The paleoclimate and the regional climatic conditions correspond well with the Middle Miocene Climatic Optimum. The mineral composition shows an abundance of quartz and calcite. Quartz is associated with detrital origin from volcanic and metamorphic rocks of the Eastern and Southern Alps and with authigenic processes in sediments. Calcite is related to authigenic origin formed in shallow marine environments and to detrital provenance from the Southern Alps. Not all discriminant functions based on major oxides provided adequate results in determining the tectonic setting. The source rocks were subjected to oceanic island arc and collision. Moreover, sedimentation was influenced by both active and passive margin settings. The former is related to the Alpine collision, which continued from the Cenozoic onward, and the latter is connected to the processes associated with the formation of the Pannonian Basin System, which began in the late Early Miocene.
Ključne besede: Central Paratethys, provenance, tectonic setting, paleoweathering, Miocene, Tunjice Hills
Objavljeno v DiRROS: 15.01.2024; Ogledov: 124; Prenosov: 44
.pdf Celotno besedilo (13,59 MB)

24.
Climate change increases the number of landslides at the juncture of the Alpine, Pannonian and Mediterranean regions
Mateja Jemec Auflič, Nejc Bezak, Ela Šegina, Peter Frantar, Stefano Luigi Gariano, Anže Medved, Tina Peternel, 2023, izvirni znanstveni članek

Povzetek: During the next few decades, changes in rainfall frequency and magnitude are expected to have major impacts on landscape evolution, social, and economic aspects of human society. We focus on seasonal rainfall variations by the end of the twenty-first century to define affected landslide-prone areas, future landslide alerts and the impact of landslides on landscape development in the juncture of the Alpine, Pannonian, and Mediterranean region. A moderate and a worst-case climate scenario from CMIP5 global climate simulations were considered to determine the impact of rainfall on the two most common types of landslides in region, shallow and deep-seated landslides. The observed changes in the occurrence of shallow landslides are significant, especially in the winter months, where we can expect more landslide-prone areas compared to the baseline period. Shallow landslides will have a greater impact on the landscape in spring and summer than deep-seated landslides, especially in vineyards.
Ključne besede: podnebne spremembe, zemeljski plazovi
Objavljeno v DiRROS: 04.01.2024; Ogledov: 213; Prenosov: 49
.pdf Celotno besedilo (3,23 MB)

25.
Multivariate statistical methods in determining the spatial distribution of chemical elements in soil from the Mavrovo-Rostuše region, North Macedonia
Trajče Stafilov, Robert Šajn, Kristina Petrovska, 2023, izvirni znanstveni članek

Povzetek: In this work, the contents and spatial distributions of 19 elements (Ag, Al, B, Ba, Ca, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, P, Pb, Sr, V, Zn) in the soil of the western part of North Macedonia (Mavrovo-Rostuše region) are presented. For this purpose, a total of 66 soil samples were collected from 33 locations (33 samples of topsoil, 0-5 cm, and 33 samples of subsoil, 20-30 cm). All samples were analysed by inductively coupled plasma - atomic emission spectrometry (ICP-AES) after complete digestion with four acids (HNO3, HF, HClO4 and HCl). The obtained results were statistically evaluated and spatial distribution maps for all analysed elements were also prepared. Factor analysis was performed to reduce the number of data used and new synthetic variables (factors) were identified. Through the application of factor analysis, three geochemical associations were identified: Factor 1 (Zn, K, Cu, Fe, and Li), Factor 2 (Cr, Ni, and Mg) and Factor 3 (Ca and Al). From the obtained data and the maps of spatial distribution, it could be concluded that the distribution of the analysed elements is related to the lithology of the region. Thus, it was found that the higher content of elements of Factor 1 occurs in the eastern and southern part of the study area (middle and lower reaches of the Radika River and along the Mala River), where Mesozoic and Paleozoic carbonates as well as Paleozoic shales and Paleogene flysch prevail. Factor 2 (Cr, Ni and Mg) also represents a lithogenic association. The highest contents of the elements in both soil layers were found in the areas where Paleozoic sandstones and shales (village of Lazaropole and the area around the Mavrovo Lake) and Paleogene flysch (Rostuše village) predominate. Factor 3 (Ca and Al) also represents lithogenic association of elements. The highest content of these elements was found in the northwestern part of the study area (village of Žirovnica and along the Berička River) and in the northeastern region above the village of Brodec where Mesozoic carbonates and Paleogene flysch dominate.
Ključne besede: soil, heavy metals, spatial distribution, Mavrovo-Rostuše region, North Macedonia
Objavljeno v DiRROS: 04.01.2024; Ogledov: 173; Prenosov: 41
.pdf Celotno besedilo (1,90 MB)

26.
Application of multivariate statistical methods for determining geochemical trends of elements on the territory of Slovenia
Robert Šajn, Mateja Gosar, Jasminka Alijagić, Tamara Teršič, 2024, izvirni znanstveni članek

Povzetek: The main objective of this study is to map multi-element geochemical anomalies in soil on a regional scale. We aimed to determine and evaluate the baseline geochemical values and main geochemical trends in soil that may serve as reference values against any future changes. A total of 817 topsoil samples (0–10 cm) were collected in a 5 × 5 km grid and analyzed for 35 elements using ICP-ES after multi-acid digestions (HClO4/HNO3/HCl/HF) and 53 elements using ICP-MS after modified aqua regia digestion (HCl/HNO3/H2O). The analytical results for the two different digestion methods (multi-acid digestion vs. aqua regia) were also compared for each chemical element. Multivariate statistical methods were applied to identify the geochemical trends and main sources of trace elements over the territory of Slovenia. Based on these results, seven natural and one mixed natural/anthropogenic geochemical association were established. The contents and trends of the determined factors are presented according to 8 natural units, 4 drainage areas, and geological units characteristic of Slovenia. The identified anthropogenic geochemical association combines toxic elements (Ag, Bi, Cd, Hg, P, Pb, S, Sn, and Zn). Increased values of these elements can be found in mining areas and metallurgic centers, in Quaternary sediments of the Sava River, and Adriatic Basin as the consequence of past mining activities and in the Julian Alps, where their origin could be connected to the atmospheric deposition.
Ključne besede: soil, geochemical mapping, distribution of geochemical elements, factor analysis, cluster analysis
Objavljeno v DiRROS: 04.01.2024; Ogledov: 168; Prenosov: 38
.pdf Celotno besedilo (9,92 MB)

27.
Heavy minerals as indicators of source material in soils on carbonates
Barbara Čeplak, Miloš Miler, Nina Zupančič, Simona Jarc, 2023, izvirni znanstveni članek

Povzetek: The origin of the soils formed on carbonate rocks remains uncertain, as they are probably of polygenetic origin. Of particular interest are the elevated contents of some trace elements detected in these soils, as they can hardly be attributed to insoluble residues of carbonate rock. The aim of this study was to uncover the relationship between heavy minerals in bedrock and soil and to identify other sources that influence the mineral and chemical composition of soil. We investigated representative samples of soils and dolomite bedrock as well as sandstones and marlstones from the nearby flysch basin as an expected source of the aeolian contribution. XRD and SEM/EDS showed that mineral diversity is higher in soils compared to the dolomites. Heavy minerals found in dolomite insoluble residue include sphalerite, Ti-oxide (probably rutile), zircon, fluorite, pyrite, minerals of REE phosphates and apatite group, interpreted as terrigenous detrital material. The mineral composition of soil heavy fraction is only partly following insoluble residues of bedrock and indicates possible aeolian contribution. Comparison with nearby flysch sandstones and marlstones showed similarities in mineralogical diversity by the presence of chromite and Fe-Cr(Mn) oxides (probably carmichaelite). Other minerals present in soils and flysch layers, such as Ti-oxide (probably rutile), zircon, REE phosphates, and pyrite grains, however, show similarities in mode of occurrence and transport indications. Signs of aeolian transport on the grains detected in soils were further confirmed by SEM/EDS.
Ključne besede: Phaeozem, Upper Triassic dolomite, flysch layers, trace elements, SEM/EDS
Objavljeno v DiRROS: 04.01.2024; Ogledov: 192; Prenosov: 40
.pdf Celotno besedilo (8,60 MB)

28.
Not another hillshade: alternatives which improve visualizations of bathymetric data
Ana Novak, Sašo Poglajen, Marko Vrabec, 2023, izvirni znanstveni članek

Povzetek: Increasing awareness of the importance of effective communication of scientific results and concepts, and the need for more accurate mapping and increased feature visibility led to the development of novel approaches to visualization of high-resolution elevation data. While new approaches have routinely been adopted for land elevation data, this does not seem to be the case for the offshore and submerged terrestrial realms. We test the suitability of algorithms provided by the freely-available and user-friendly Relief Visualization Toolbox (RVT) software package for visualizing bathymetric data. We examine the algorithms optimal for visualizing the general bathymetry of a study area, as well as for highlighting specific morphological shapes that are common on the sea-, lake- and riverbed. We show that these algorithms surpass the more conventional analytical hillshading in providing visualizations of bathymetric data richer in details, and foremost, providing a better overview of the morphological features of the studied areas. We demonstrate that the algorithms are efficient regardless of the source data type, depth range, resolution, geographic, and geological setting. The summary of our results and observations can serve as a reference for future users of RVT for displaying bathymetric data.
Ključne besede: bathymetry, RVT, visualization, hillshade, geomorphology, marine geology, multibeam
Objavljeno v DiRROS: 01.12.2023; Ogledov: 179; Prenosov: 60
.pdf Celotno besedilo (15,49 MB)

29.
Atmosphere–cryosphere interactions during the last phase of the Last Glacial Maximum (21 ka) in the European Alps
Costanza Del Gobbo, Renato R. Colucci, Giovanni Monegato, Manja Žebre, Filippo Giorgi, 2023, izvirni znanstveni članek

Povzetek: Evidence that during the Last Glacial Maximum (LGM) glaciers extended well into the piedmont plains is still identifiable in the alpine foreland as a system of well-preserved moraines. Glaciers are strongly controlled by temperature and precipitation, and therefore, they are excellent indicators of climate change. Here, we use a regional climate model (RCM) to investigate some of the physical processes sustaining Alpine glaciers during the last phase of the LGM during Greenland Stadial 2 at 21 ka. We find a predominance of convection during summer and increased southwesterly stratiform precipitation over the southern Alps when compared to pre-industrial (PI) conditions. This precipitation pattern, along with lower temperatures, determined summer snowfall extending to low elevations, with a consequent substantial drop of the equilibrium line altitude (ELA), which is consistent with the estimated LGM glacier extent. Our RCM-based estimates of 21 ka ELA at the LGM yield excellent consistency with Alpine ELA reconstructions, further demonstrating the great potential of this technique for use in palaeoclimate studies.
Ključne besede: Quaternary, ice age, atmosphere, glaciers, climate change, the Alps
Objavljeno v DiRROS: 19.09.2023; Ogledov: 325; Prenosov: 111
.pdf Celotno besedilo (10,56 MB)

30.
Impact of Open-Loop Systems on Groundwater Temperature in NE Slovenia
Simona Adrinek, Mitja Janža, Mihael Brenčič, 2023, izvirni znanstveni članek

Povzetek: To achieve sustainable and efficient use of shallow geothermal resources, it is important to understand the heat transfer in the subsurface of the planned geothermal system. In the City Municipality of Murska Sobota, NE Slovenia, the use of geothermal open-loop systems has increased in recent years. Their high spatial density raises the question of possible mutual interference between the systems. By compiling geological, hydrogeological, and thermal data, obtained from the monitoring network, fieldwork, and knowledge of regional hydrogeological conditions, we have developed a transient groundwater flow and heat transfer model to evaluate the impact of the open-loop systems on the subsurface and surrounding systems. The transient simulation showed that the thermal state in the observed area is restored over the summer, when the systems are not in operation. Also, the systems do not have significant mutual interference that would affect their efficiency. However, as interest in installing new systems in the area increases, simulations of the thermal plumes of new geothermal systems are needed to ensure sustainable and efficient use of shallow geothermal energy in the future.
Ključne besede: geothermal energy, open-loop system, groundwater heat pump, intergranular aquifer, numerical modelling, thermal plume
Objavljeno v DiRROS: 19.09.2023; Ogledov: 334; Prenosov: 90
.pdf Celotno besedilo (36,17 MB)

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