rss_2.0Sciendo RSS Feed for Austrian Journal of Earth Scienceshttps://sciendo.com/journal/AJEShttps://www.sciendo.comhttps://sciendo-parsed.s3.eu-central-1.amazonaws.com/64708f0671e4585e08a9ff65/cover-image.jpghttps://sciendo.com/journal/AJES140216https://sciendo.com/article/10.17738/ajes.2024.0011<abstract> <title style='display:none'>Abstract</title> <p>The Upper Cretaceous limestones of Bjelopavlići (Montenegro) represent a megasequence of facies reflecting a transition from shallow- to deep-water depositional environments, succeeded by re-establishing shallow-water conditions again. The studied carbonate sequences are exposed on the south-eastern edge of the Adriatic Carbonate Platform (AdCP) in central Montenegro. Based on coupled sedimentological and biostratigraphical studies, the associations of eight spatially and temporally related facies were identified. The lower part of the megasequence comprises shallow-water carbonates originating in the inner-platform area, while the middle part is composed of pelagic and allodapic limestones. Shallow-water platform limestones occupy the upper part of the megasequence. The shallow-water carbonates of Bjelopavlići show a good correlation with the shallow-water Upper Cretaceous sediments in the AdCP. Deep-water limestones of Bjelopavlići are regarded as facies correlative to the spatially distinct deep-water limestones of Brač and as temporary and spatially correlative with slope-to-basin facies derived along the north-eastern margin of the AdCP. The drowning of the platform periphery and the evolution of a deep-water basin where the pelagic and allodapic carbonates of Bjelopavlići were deposited, as well as the subsequent exhumation of the platform are predominantly attributed to tectonics. The uppermost Cretaceous dynamics of the basin were controlled by tectonic mobilization of the foreland in front of regional fold-thrust belts that developed north-eastern from the AdCP.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2024.00112024-08-31T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2024.0010<abstract> <title style='display:none'>Abstract</title> <p>The Totes Gebirge is not only the largest karst massif in the Northern Calcareous Alps, it also contains the most cave passages. In this area we are investigating the vertical distribution of phreatic cave passages to determine cave levels. These are vertical zones with clusters of cave passages that can be correlated with former valley floors. Since only phreatic cave passages (i.e. caves that were permanently or episodically filled with water during their formation) are to be analysed, a genetic classification is made on the basis of field observations, cave maps, 3D surveys and descriptions.</p> <p>As of Sept. 2023, the Totes Gebirge range, including the adjacent Warscheneck and the Hohe Schrott, contains 3172 known caves with a total length of 821 km, including the two longest cave systems in Austria, the Schönberg- (156 km) and the Schwarzmooskogel-Höhlensystem (137 km). As small caves do not contribute significantly to these statistics, only caves ≥50 m were included. The remaining 754 caves have a total length of 790 km. Only 46 % of these caves are at least partially of phreatic origin, but they contain 92 % of the total passage length. After subtracting the caves from which no data were available and cave sections that are not phreatic in origin (i.e. vadose or those created by weathering and erosion), 641 km of cave sections remained, which were analysed for their vertical distribution in 25 m increments.</p> <p>The histogram of cave length distribution vs. elevation for the Totes Gebirge range shows only a single significant cluster of phreatic cave sections between 1300 and 1850 m above see level (a.s.l.), with a clear maximum at 1500 m. The massif was divided into four sub-regions and all of them show this main interval, which is why it was interpreted as a cave level. It correlates well with the Giant Cave Level known from all other karst massifs in the Northern Calcareous Alps analysed so far. However, it is peculiar that in the other massifs at least three cave levels are present. Other reasons, such as the lack of known caves and the large size of the massif, which could lead to overlapping of cave levels, are unlikely. Therefore, it seems possible that the palaeo surface drainage pattern around the Totes Gebirge or its uplift history was different from the other karst massifs in the Northern Calcareous Alps and that low-lying cave levels (Spring and Berger Cave Level) or an elevated one (Ruin Cave Level) did not develop. For each of the 21 largest cave systems (≥5 km in length), the peak of the vertical distribution of the phreatic passages was determined. Vectors were calculated in order to test whether palaeo-flow directions could be inferred from their distribution. These phreatic maxima indicate a general dip from ESE to WNW, which could be interpreted either as a palaeo-drainage direction or as a tectonic tilting of the whole massif after the formation of the passages.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2024.00102024-08-31T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2024.0008<abstract> <title style='display:none'>Abstract</title> <p>New biostratigraphic data derived from the stratotype of the Gutenstein Formation at the village Gutenstein (Lower Austria) help to solve some long-standing problems about the stratigraphy of the Anisian stage within the eastern part of the Northern Calcareous Alps. At Gutenstein, the lower lithostratigraphic boundary of the Anisian Gutenstein Formation to the underlying lower Anisian Reichenhall Formation is defined, assuming a normal stratigraphic contact of the Reichenhall Formation to the underlying Werfen Formation and to the overlying Gutenstein Formation. Microfacial data confirm the sedimentary origin of the rauwackes of the Reichenhall Formation. A detailed lithostratigraphic and facies-oriented definition of the Gutenstein Formation includes prevailing thin and planar-bedded, black colored, sometimes fine-bedded limestone (rarely dolostone) and radiolarian (calcispheres) bearing, black colored mud- to wackestone, mostly containing some fine crinoid debris. Upsection, a quick change to an upper (Pelsonian) member of the Gutenstein Formation with nodular bedding planes and brachiopod-, crinoid-, conodont- and ammonite accumulations is presented. The general depositional environment of the Gutenstein Formation is interpreted as a dysoxic outer carbonate ramp deposit, with a shallowing upward trend to rather thick-bedded mid- and inner carbonate ramp settings of the Annaberg- and Steinalm formations. The approximate interval of the Anisian/Ladinian boundary within the type-section of Gutenstein is determined with help of new fossil findings such as dasycladalean green-algae. Based on distinct lithological differences on a regional scale, which occur in thick basinal stratigraphic successions within the Gutenstein Formation like at Großreifling (Styria, Bajuvaric Nappe System), at Innerfahrafeld (elevation Fuchsriegel, Lower Austria) and on mount Kasberg at Grünau (Upper Austria, Tirolic Nappe System), a subdivision of the Gutenstein Formation into a lower <italic>Gutenstein Member</italic>, and an upper <italic>Kasberg Member</italic> (= <italic>Upper Gutenstein Formation</italic>), is proposed herein. The lower member corresponds to the black, thin- and planar-bedded interval, whereas the Kasberg Member is characterized by nodular bedding planes, greater bed thicknesses and higher fossil content.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2024.00082024-06-30T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2024.0009<abstract> <title style='display:none'>Abstract</title> <p>Today’s landscape and morphology of Austria is markedly affected by erosional and sedimentary processes active during the Quaternary. Particularly, large glaciers have shaped the landscape of the Eastern Alps. The presented maps at the scales of 1:500 000 and 1:1 500 000 aim to visualise areas, where deposition or erosion in different stages of the Quaternary prevailed. The maps (free download available) were generated with ArcGIS software using available map sheets at larger scales (1:50 000, 1:200 000). No additional field work has been conducted. The most obvious observation is that an extensive cover of Quaternary sediments predominantly occurs in the northern Alpine foreland, especially outside of Austria.</p> <p>The maps show that large glacier tongues of the Middle to Late Pleistocene glaciations (Günz, Mindel, Riss and Würm) existed in the northern and southeastern alpine foreland. In the east, hardly any signs of glacial coverage are visible due to later fluvial cannibalisation of features partly deposited in narrow valleys. Bordering terminal moraines, extensive, terraced fluvial deposits occur within and around the Alps showing that river courses partly changed during the Pleistocene. Aeolian sediments often accompany these sediments, but also cover huge areas in the Vienna and Tulln Basin and the Little Hungarian plain. The distribution of large rockslide events shows that they mainly formed in glacially covered areas as a result of rock destabilisation after glacier retreat. Additionally, the map shows that the alpine foreland is subject of inhomogeneous uplift since the Neogene. For example, between Salzburg and Munich, wide areas are covered by Pleistocene deposits, whereas to the west of Munich and in Upper Austria, recent rivers incised deeper into Neogene sediments.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2024.00092024-06-30T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2024.0007<abstract> <title style='display:none'>Abstract</title> <p>A regional tungsten anomaly was discovered and explored in the Lienzer Schlossberg area that is part of the crystalline Austroalpine nappe complex of the Eastern Alps in the 1970/80-ties. Tungsten is present as scheelite, which occurs in steeply SSW dipping WNW-ENE oriented quartz veinlets and joints within the porphyritic dioritic to tonalitic/granodioritic host rocks of the Oligocene Lienz/Edenwald intrusion and in the exoskarn, which developed at the contact of the intrusion with Ca-rich lithologies. The skarn system is characterised by two stages: (1) a primary high-temperature calc-silicate stage characterised by grossular, diopside-hedenbergite, vesuvianite, wollastonite and Ca-plagioclase and (2) a retrograde skarn stage including scheelite-bearing massive sulphide ores (pyrrhotite, chalcopyrite, tremolite-actinolite, diopside-hedenbergite) and scheelite-rich fault rocks with calcite, sericite and chlorite. The two ore stages, the mineral paragenesis and composition is like that of a reduced tungsten skarn; i.e., garnet is grossular-rich, clinopyroxene is diopside-hedenbergite. Vesuvianite contains up to 1.8 mass % fluorine. Scheelite has been studied by cathodoluminescence (CL), electron probe microanalysis and laser ablation-inductively coupled plasma-mass spectrometry. Three types of scheelite (Scheelite 1–3) are distinguished. In short-wave UV light, all types show blue fluorescence but CL revealed internal micro-textures in scheelite grains which are dominated by oscillatory zoning. Prolonged hydrothermal activity is indicated by dissolution-replacement and overgrowth textures affecting the primary zonation and trace element composition of scheelite. The distribution of rare earth elements (REE) in Scheelite 1 in tonalite-hosted quartz veinlets shows a convex (i.e., middle REE-enriched), heavy REE-depleted pattern with negative Eu anomalies (<italic>Eu_A</italic>). The evolution of REE patterns from skarn-hosted Scheelite 2 and 3 illustrates a gradation of convex REE patterns with high ΣREE and distinct negative Eu anomalies to relatively flat REE patterns with small to no <italic>Eu_A</italic>. Scheelite at Lienzer Schlossberg has one of the highest ΣREE+Y contents of all scheelite-bearing ore settings in the Eastern Alps but incorporates minor Mo and the least Sr. High Na and Nb contents together with the positive correlation of REE+Y vs. Na+Nb+Ta suggests that the main exchange vectors for REE incorporation in scheelite is via a combined coupled substitution mechanism. Results of this study confirm the genetic similarity with reduced tungsten skarns and highlight the tungsten potential of this area.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2024.00072024-06-22T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2024.0005<abstract> <title style='display:none'>Abstract</title> <p>Low-relief surfaces at high elevations are peculiar features of the Eastern Alps that are best explained as relicts of morphological base levels that escaped erosive decay during uplift. To expand our knowledge of such surfaces in the Eastern Alps, the Fischbach Alps at the eastern end of the range are investigated. There, a large number of these elevated low-relief surfaces have been known for some time, but modern mapping is absent and their genesis is not well understood. A combined approach of field mapping, morphometric analysis of a digital elevation model and downstream projection of geomorphic equilibrium sections in river profiles was employed to: (i) create a geomorphological map of the region and (ii) to extract quantitative data from river profiles to infer the amount of uplift and incision. Six discrete levels of low-relief surfaces and relict landscapes are recognized at elevations between ~500 m and ~1600 m. Some of the lower levels are interpreted to relate to the well-known <italic>Trahutten, Landscha</italic> and <italic>Stadelberg</italic> levels, known from other parts of Styria, respectively. Mapped low-relief surface levels follow the northward directed topographic gradient in the mountainous region of the Fischbach Alps. The formation of elevated low-relief surfaces is consistent with a Piedmonttreppen model, where successive phases of tectonic uplift and tectonic quiescence led to a succession of incised landscapes and low-relief surfaces. However, the entire region south of the Murztal was also then tilted towards the Styrian Basin by about ~1–2°. Swath profile analysis for the Raab and Weizbach Klamm suggests a minimum of ~400–450 m incision since the formation of the so called <italic>Hubenhalt</italic> level. This implies that the geomorphic response to tectonic uplift after the formation of the higher <italic>Wolscheneck</italic> and <italic>Koralm</italic> relict landscapes led to an estimated incision of up to 1000 m (868±101 m), relative to the base level of today’s Styrian Basin at ~380 m. By comparing published age data to the presented mapping results, the onset for much of the uplift at the eastern end of the Alps is suggested to lie between ~4–7 Ma, before the formation of the <italic>Hubenhalt</italic> and <italic>Trahutten</italic> levels. Because the mapped levels correlate well with those in many other regions at similar elevations, a growing body of work now suggests that the underlying uplift event has a large wavelength.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2024.00052024-05-10T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2024.0006<abstract> <title style='display:none'>Abstract</title> <p>The Carnic Alps (eastern Southern Alps) provide a classical area to study polyphase very-low- to low-grade metamorphism within the Variscan belt of Europe. Temperature indicators collected during the past three decades map the general metamorphic structure of a mountain chain affected by three major tectonic events (Variscan and Alpine thrusting, Oligocene transpression). Thermometric data obtained by Raman Spectroscopy of carbonaceous material (RSCM) described in this study extend the already published database, provide a map of metamorphic isotherms, and are interpreted in the view of current tectonic concepts. The RSCM temperatures of this study describe a gradient between ca. 460 °C in the tectonically deepest segments, bordered by the Periadriatic Fault System, and temperatures of ca. 200 °C in Permian- Triassic boundary strata of the Gartnerkofel-1 core. Mapped isotherms indicate three domains with different thermal histories, characterized by Variscan imbrication of an accretionary wedge, Permo-Mesozoic burial, and Oligocene contact metamorphism.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2024.00062024-05-10T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2024.0004<abstract> <title style='display:none'>Abstract</title> <p>Recently, samples of natrochalcite, NaCu₂(SO₄)₂∙H₃O₂, were discovered from the Esperanza Mine, Lavrion Mining District, Greece. In the present study this material is characterized by single crystal X-ray diffraction at ambient and LT conditions. Natrochalcite is monoclinic, space group <italic>C</italic>2/<italic>m</italic>, with <italic>a</italic> = 8.809(2), <italic>b</italic> = 6.196(1), <italic>c</italic> = 7.504(2) Å, <italic>β</italic> = 118.56(3)°, <italic>V</italic> = 359.7(1) ų, <italic>Z</italic> = 2, <italic>R</italic>1 = 0.0195 at room temperature. No symmetry change was observed down to 100K.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2024.00042024-03-28T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2024.0003<abstract> <title style='display:none'>Abstract</title> <p>In the 1980s, large parts of the Bohemian Massif in Austria were explored for the occurrence of raw materials (Göd, 1988), and a trace content of topaz was discovered in channels draining the eastern slope of the Ostrong (Lower Austria). Orthogneiss bodies in the Ostrong Nappe System are shown to be the source of these topaz occurrences, and Raman spectroscopy indicates that topaz is fluorine rich. So far, this is the only occurrence of topaz-bearing orthogneiss within the entire Moldanubian Superunit. The orthogneiss shows a tectonic overprint and exhibits a weak to well-developed foliation, as well as local folding. Samples taken near the tectonic boundary of the Ostrong to the Drosendorf Nappe Systems show stronger shear deformation with a pronounced mylonitic foliation and stretching lineation. Detailed geo-chemical investigations of the major and trace elements indicate a classification as S-type granite with a high degree of differentiation and a peraluminous character. The orthogneiss has a high SiO₂ content of 72.8–77.3 wt%, as well as a noteworthy high fluorine content of up to 2760 ppm. Mineral compositions show zoned plagioclase with an albite component of about 87–99 mol%, increasing towards the grain margin. Garnet occurs rarely, but consistently in those samples near the tectonic boundary of the Ostrong- to the Drosendorf Nappe Systems. Garnet is almandine-dominated, shows no zoning and is single-phased. Sillimanite is common and samples near the tectonic boundary also contain kyanite. To determine the previously unknown protolith age of the orthogneiss, U-Pb zircon dating was applied. Three zircon fractions from two samples yield concordia ages of 475.3 ± 1.0 Ma, 474.8 ± 2.9 Ma, and 473.5 ± 1.5 Ma, identical in assigned uncertainties, reflecting magmatic zircon growth. Furthermore, the short prismatic habit of zircon grains indicates a plutonic rather than volcanic origin of the protolith. Dating results also provide a minimum sedimentation age for the rocks of the Ostrong Nappe System within Austria. In comparison with other metagranitoids and orthogneisses of the Moldanubian Nappes, the investigated orthogneiss shows strong similarities with the Gföhl Gneiss and the Moldanubian Granulite. The orthogneiss therefore is considered as a more fractionated equivalent of the Gföhl Gneiss. In conclusion we suggest to name the studied orthogneiss <italic>Laimbach Orthogneiss</italic> in the rank of a lithodeme (NACSN, 2005), after the locality Laimbach am Ostrong (48°19′01″N; 15°07′19″E), which is located centrally with respect to the occurrences of this gneiss.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2024.00032024-03-02T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2024.0002<abstract> <title style='display:none'>Abstract</title> <p>Ophiolites are remnants of oceanic crust and mantle, now typically found within continental mountain ranges like the Alps. Particularly in areas once part of the Tethys Ocean, ophiolites are often accompanied by narrow stripes of metamorphic rocks, commonly referred to as metamorphic soles. These metamorphic soles typically exhibit peak metamorphic conditions characteristic of either granulite or amphibolite facies. Geochronological studies of Tethyan ophiolites indicate that the development of these metamorphic soles occurred almost simultaneously with the crystallization of the ophiolite’s crustal sequence. Geological evidence also suggests that the metamorphism of the sole rocks took place concurrently with deformation, likely at the same time as the ophiolite’s obduction. In our research, we explore the metamorphic effects of shearing in an ophiolite sequence overlying a crustal sequence. Our findings reveal that strong lithologies like ophiolites can produce additional heat through the dissipation of mechanical energy, which can potentially explain the high temperatures found in metamorphic-sole rocks. In addition, heating-driven softening of the footwall rocks eventually leads to the migration of the active shear zone from the mantle sequence into the upper crustal domain. This migration may be responsible for the metamorphic sole incorporation at the base of the ophiolite. Finally, we demonstrate that stopping the shearing process rapidly cools these rocks, corresponding with the findings from thermochronological studies from Oman ophiolite.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2024.00022024-03-01T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2024.0001<abstract> <title style='display:none'>Abstract</title> <p>Extensive bulk-sampling of the continuous Cretaceous-Paleogene boundary section at Gams (Styria, Austria) allows for the first time the description of the elasmobranch communities inhabiting the bathyal environment of this well-known section. The sampled succession comprises six horizons from the uppermost Maastrichtian (upper part of <italic>Nephrolites frequens</italic> Zone CC26) and five horizons from the lowermost Danian (Zone NP1), which yielded a total of 1852 elasmobranch teeth. Although the majority of the teeth are not well preserved, this study enabled the description of at least 16 taxa of the orders Hexanchiformes, Squaliformes, Orectolobiformes, Lamniformes and Carcharhiniformes, providing a rare snapshot of elasmobranch diversity of this specific environmental setting. Beside minor diversity fluctuations between the assemblages, the extensive bulk-sampling of this section did not reveal a marked diversity decline related to the end-Cretaceous mass extinction event. However, a noteworthy correlation between the deepening upward trend of the section with the appearance of frilled and goblin sharks points to changes in palaeobathymetry, which is also reflected in the increase of the total proportion of squaliform teeth in the uppermost sampled horizon. Furthermore, teeth of the extinct triakid <italic>Palaeogaleus</italic> were recovered exclusively from the Danian deeper deposits, expanding the palaeoecological range of the genus down to fairly deep marine environments. In addition, this study provides the first record of the lamniform <italic>Cretolamna</italic> ex gr. <italic>borealis</italic> from the Danian of the Tethyan Realm expanding the palaeogeographic distribution of this group.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2024.00012024-02-03T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2023.0010<abstract> <title style='display:none'>Abstract</title> <p>Eclogites in the Texel Unit (Austroalpine nappe stack; Eastern Alps, South Tyrol, Italy) represent the westernmost out-crops of the E-W striking Eoalpine High-Pressure Belt (EHB). East of the Tauern Window, the EHB forms part of a Cretaceous intracontinental south-dipping subduction/collision zone. The impetus of this contribution is to extend the geothermo-barometric data of the eclogites from the EHB using conventional geothermobarometry and multi-equilibrium calculations as well as Zr-in-rutile/titanite geothermometry and to put the <italic>P</italic>-<italic>T</italic> results of eclogites and amphibolites from the Texel Unit into the geodynamic framework. The investigated samples of this study are from the Spronser- and the Saltaus valleys (S-Tyrol) in the Austroalpine Texel Unit. The Texel Unit is composed mainly of paragneisses with minor intercalations of micaschists, orthogneisses, amphibolites and subordinately eclogites. The amphibolites from the Spronser valley contain the mineral assemblage amphibole + plagioclase + garnet + clinozoisite/epidote + quartz + titanite ± ilmenite ± rutile ± apatite ± calcite. Chemical zoning in plagioclase and amphibole shows two main growth stages: an older <italic>P</italic>-dominated stage (e.g. albite and barroisite cores) and a younger amphibolite-facies stage. The core of the amphiboles shows barroisite composition, the rim can be chemically classified as hornblende, edenite, tschermakite and pargasite. Geothermobarometric calculations with multi-equilibrium geothermobarometry (THERMOCALC v.3.21) yield temperatures of 600–654°C and pressures of 0.98–1.17 GPa for the same samples. The eclogites from the Saltaus valley contain the peak mineral assemblage omphacite + amphibole + garnet + clinozoisite/epidote + muscovite + quartz + titanite ± ilmenite ± rutile. Thermobarometric calculations, were performed in the system CaO-FeO-MgO-Na₂O-Al₂O₃-FeO-SiO₂-H₂O with the assemblage clinopyroxene + garnet + amphibole + clinozoisite/epidote + muscovite + quartz ± H₂O. The calculations involved an H₂O-absent invariant point (mode-1 calculation) as well as two types of <italic>average P</italic>-<italic>T</italic> mode-2 calculations. The obtained <italic>average P</italic>-<italic>T</italic> H₂O-absent mode 1 <italic>P</italic>-<italic>T</italic> conditions are 1.89 ± 0.18 GPa and 578 ± 60°C. Using the <italic>average P</italic>-<italic>T</italic> mode-2 two types of calculations were done: (1) calculations without amphiboles but with H₂O present, which yield mean <italic>P</italic>-<italic>T</italic> conditions of 1.95 ± 0.28 GPa and 601 ± 55°C and (2) calculations with amphiboles but without H₂O, which yield mean <italic>P</italic>-<italic>T</italic> conditions of 1.95 ± 0.26 GPa and 666 ± 77°C. Calculations using THERMOCALC v.3.33 yield similar results with slightly higher pressures of 0.3 GPa. Based on the present geothermobarometric data in conjunction with available mineral ages the eclogites represent the Eoalpine intracontinental subduction stage whereas the amphibolites reflect the subsequent, P-accentuated stage of decompression associated with the subsequent Eoalpine collisional stage.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2023.00102023-12-15T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2023.0009<abstract> <title style='display:none'>Abstract</title> <p>This paper investigates the vertical distribution of horizontal and subhorizontal cave passages in the Dachstein Massif of Austria. Cave passages that are confined to vertical ranges, so-called cave levels, can be correlated with former valley floors and thus reflect tectonically and climatically stable periods. Previous studies analyzed significant karst Massifs (or parts of them) in the Northern Calcareous Alps but have excluded the Dachstein massif so far. The Dachstein is the second largest massif in the area, contains many extensive caves, and plays a key role in reconstruction of landscape evolution (“Dachstein surface”). In contrast to some previous works, we aimed to analyze only passages that formed (or are forming) under phreatic or epiphreatic conditions (i.e. permanently or episodically water-filled). This genetic classification is based on field observations, cave maps, 3D survey shots and descriptions. For this study, 789 caves with a total length of 279 km were considered, but data were only available for 599 caves (276 km). Only 25% of all caves in the Dachstein Massif are at least partly of (epi)phreatic origin, but the total length of phreatic passages is 204 km. Altitudes of the phreatic sections of each cave were grouped in 25-m increments and plotted according to their phreatic passage length. It turned out that there are five vertical accumulations of caves in the Dachstein Massif. Despite some previous studies that also considered morphological, hydrological, and sedimentological characteristics, our correlation with the “classical” supra-regional cave levels in other karst massifs was based only on elevation. The following elevations for the cave levels were determined: Spring Cave Level: 475-775 m a.s.l., Berger Cave Level: 825-1075 m, Giant Cave Level (with the highest peak): 1125-1550 m, Ruin Cave Level: 1600-2050 m, and a formerly unknown level at 2525-2750 m, for which we propose the name Voodoo Cave Level. According to this study the two longest cave systems, the Hirlatzhöhle (114 km long and 1560 m deep) and the Dachstein-Mammuthöhle (68 km, 1207 m) are most relevant for the result. The local vertical distribution of caves within the Dachstein was compared with the regional northward tilt of cave levels in the Northern Calcareous Alps, however the heterogeneous distribution of the known cave obscures local effects in the Dachstein Massif.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2023.00092023-11-26T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2023.0008<abstract> <title style='display:none'>Abstract</title> <p>Being able to create digital geological maps has become a basic requirement for the skillset of today’s geologists. QGIS is a geographical information system that receives increasing popularity due to its user-friendliness and the fact that it is an open access software. This contribution provides an update and extension to a previously published software guideline that gives a stepwise explanation on how to create a geological map with QGIS. The article serves as a brief overview of the guideline through an illustrated example. The guideline itself is published as a supplement to this paper. Within six sections, the guideline explains how to create a geological map with QGIS: 1. Introduction, 2. Download and installation, 3. Basemaps, 4. Map drawing, 5. Plugins, 6. Layouts. The aim is to instruct geologists who are completely inexperienced with digital map creation as well as provide specific information for more advanced users. In general, providing software guidelines for the geological community is an important step towards increasing geologists’ digital proficiency and to keep up with today’s fast paced developments in digitalization.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2023.00082023-10-18T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2023.0007<abstract> <title style='display:none'>Abstract</title> <p>Karst springs play a central role in Austria’s water supply. This paper aims to provide an overview of the karst springs of Lower Austria, analysing statistical correlations of spatial distribution, discharge, electrical conductivity (EC), and temperature. As part of a project with the provincial government of Lower Austria, older data from numerous studies have been combined with the self-generated data in a GIS database. This database contains data on 2056 karst springs. Most of the recorded springs are located in the Northern Calcareous Alps, although karst springs also occur in the Central Alpine Permomesozoic, the Waschberg zone and the Bohemian Massif, some of which are also of regional importance for drinking water supply. Chemical analyses show that limestone, dolomite and mixed springs are widespread in Lower Austria and occur with similar frequency. Gypsum springs, which are characterised by a significantly higher total mineral-isation, are also of regional importance. The statistical analysis shows that spring water temperatures correlate well with the mean annual air temperature at the mean catchment elevation. The temperature decrease with increasing elevation corresponds to the air temperature gradient in the Eastern Alps (0.47 °C/100 m). In addition, the springs show a negative correlation of the EC with the mean catchment elevation, which can be explained by a decrease in soil cover and thus reduced CO₂ uptake of the water, as well as dilution by rainwater. This leads to less carbonate dissolution, which is also reflected in less HCO₃⁻ contents. Corrected for the elevation effect, the investigated dolomite springs, have on average a 2.7% higher EC than limestone springs. A difference was also found between the Hauptdolomit and the Wettersteindolomit rock types, which are widespread in Lower Austria, with the latter displaying higher values on average by 2.2%. This indicates longer residence times of the spring water due to less karstification of the Wettersteindolomit.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2023.00072023-09-30T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2023.0006<abstract> <title style='display:none'>Abstract</title> <p>The Krems Embayment contains the westernmost fully marine depositional environments of the Karpatian and Bade-nian transgressions in the Central Paratethys. Four drill cores were investigated to analyse the bio- and lithostratigraphic, and tectonic relations. The investigated core sections cover the Karpatian Laa Formation (bio-zones M4, NN4) and the Badenian Gaindorf Formation (M5b-M6, NN4-NN5). Important biostratigraphic indicators identified are <italic>Praeorbulina glomerosa glomerosa, Praeorbulina glomerosa circularis</italic> and <italic>Orbulina suturalis</italic> for the Gaindorf Formation. The Laa Formation is indicated by the absence of <italic>Praeorbulina</italic>, <italic>Orbulina</italic> and <italic>Globigerina falconensis</italic>, low numbers of <italic>Globorotalia bykovae</italic>, and a prominent peak in <italic>Helicosphaera ampliaperta</italic> abundance at the end of the Karpatian. <italic>Cibicidoides lopjanicus</italic> and <italic>Cassigerinella</italic> spp. occur with high percentages in Badenian samples and show much longer stratigraphic ranges than known from literature data. The depositional gap at the Karpatian-Badenian boundary has a minimum duration of 0.41 My in the Krems Embayment. The combination of bio- and lithostratigraphic data allows the correlation across major faults. The Diendorf-Boskovice Fault System played an important role during basin formation and was identified as very active during the early to middle Badenian Stage. The results of this study show the complex interaction of sedimentation, tectonic activity and paleobiological developments in this peripheral part of a marginal sea.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2023.00062023-06-30T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2023.0005<abstract> <title style='display:none'>Abstract</title> <p>The proto-Alpine Cenerian orogen (Ediacaran-Ordovician) and the Cadomian orogen (Ediacaran-Cambrian), remnants of which are exposed in the central European Variscides, should be defined as two distinct and spatially separated coastal orogens within the Avalonian-Cadomian belt. The Cadomian orogen originally lay in front of the Sahara metacraton. It underwent a change from an active to a passive margin setting during the Cambrian. The Cenerian orogen, represented by intra-Alpine rocks, was located farther east near the Arabian Nubian Shield, from where it inherited a characteristic Tonian/Stenian detrital zircon signal. Subduction persisted in the Cenerian Orogen until the Ordovician. The Cadomian orogen was akin to Andean type whereas the Cenerian orogen was more akin to Alaskan type. This paper explores why the two orogens have such different characteristics and tectonic evolutions despite their probable proximity in the Avalonian-Cadomian belt. One explanation could be that they were at nearly right-angles to each other due to a strong concave bending of the northern Gondwana margin ahead of the Arabian-Nubian Shield.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2023.00052023-05-16T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2023.0002<abstract> <title style='display:none'>Abstract</title> <p>The Bohemian Massif is the relic of a major Paleozoic mountain range that is known to have exhumed and its surface levelled in the Permian, but its Neogene landscape evolution is largely unconstrained. The landscape is characterized by rolling hills and extended planation surfaces above an elevation of about 500 m. However, at lower elevations deeply incised gorges confined by steep hillslopes are abundant and contrast impressively with the low relief landscapes above. Rivers with a bimodal morphology (i.e. steep at lower elevations and gentle at higher elevations) drain either to the north into the Vltava (Moldau) River or to the south into the Danube River. Hence, a continental drainage divide runs through the Bohemian Massif. Here, we quantify spatial characteristics of the Bohemian Massif landforms by computing landscape metrics like steepness index or geophysical relief derived from digital elevation models. From this we infer temporal change of the landscape in the past and predict them for the future evolution of the region.</p> <p>We show that the landscape is characterized by out-of-equilibrium river profiles with knickpoints abundantly at elevations between 450 m and 550 m separating steep channel segments at lower elevations from less steep channels at higher elevations. Hypsometric maxima at or close above knickpoint elevations, along with high and low values in geophysical relief as indicator for the degree of fluvial landscape dissection downstream and upstream of major knickpoints, support the idea of landscape bimodality. Furthermore, we find a distinct drainage divide asymmetry, which causes the reorganization of the drainage network of the region. Across-divide gradients in channel steepness predict the northward migration of the Danube-Vltava drainage divide including growth and shrinkage of tributary catchments, thus controlling changes in the Central European drainage pattern.</p> <p>All aspects suggest that the region experienced relief rejuvenation during the last few million years. We suggest that this relief rejuvenation is related to the inversion of the Molasse basin with a long wavelength rock uplift pattern and low uplift rates. Vertical motion of crustal blocks at discrete faults may locally affect the uplift pattern. However, the contrasting bedrock properties between the sedimentary cover (Molasse sediments) and the crystalline basement (Bohemian Massif) cause substantial differences in erosion rate and are thus the superior control on the topographic variations of the entire region.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2023.00022023-02-17T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2023.0001<abstract> <title style='display:none'>Abstract</title> <p>The Vienna Basin Transfer Fault System (VBTFS) is the most active fault system in the region between the Eastern Alps, the western Carpathians and the Pannonian Basin. The spatial and temporal distribution of earthquakes along the fault system shows a heterogeneous pattern including a long-time decay of seismicity at the northern part of the VBTFS, which was interpreted to result from a long aftershock sequence subsequent to the 1906 Dobrá Voda earthquake (M=5.7). In this paper we investigate if other segments of the VBTFS display similar long-term declines of seismicity that might indicate long aftershock sequences following strong, yet unrecorded, earthquakes in historical times.</p> <p>In order to analyse the distribution of seismicity, the VBTFS is divided into arbitrary segments of about 50 km length each. The segments are chosen to overlap each other to avoid missing information from neighbouring segments due to arbitrarily selected segment boundaries. For each segment we analyse the temporal evolution of seismicity and calculate the parameters of the corresponding Gutenberg-Richter (GR) relation.</p> <p>The temporal seismicity patterns revealed from the segments covering the Dobrá Voda area confirm the protracted aftershock sequence following the 1906 earthquake. All but one of the other segments do not show temporal changes of seismicity comparable to the long-term Dobrá Voda aftershock sequence. Seismicity patterns, however, include short-term Omori-type aftershocks following moderate earthquakes such as the 2000 Ebreichsdorf earthquake (M=4.8). The segment covering the SW tip of the VBTFS revealed a 200 years long gradual decrease of the largest observed magnitudes starting with the 1794 Leoben (M=4.7) earthquake. The 1794 event is the oldest earthquake listed in the catalogue for the region under consideration. It therefore remains open if the recorded decay of seismicity results from the 1794 event, or a stronger earthquake before that time. The latter is corroborated by the low magnitude of the 1794 earthquake which would typically not be considered to cause long aftershock sequences.</p> <p>GR a- and b-values, calculated for the individual segments, vary significantly along the VBTFS. Values range from 0.47 to 0.86 (b-values) and 0.81 to 2.54 (a-values), respectively. Data show a significant positive correlation of a- and b-values and a coincidence of the lowest b-values with fault segments with large seismic slip deficits and very low seismicity in the last approximately 300 years. These parts of the VBTFS were previously interpreted as “locked” fault segments, which have a significant potential to release future strong earthquakes, in spite of the fact that historical and instrumentally recorded seismicity is very low. We find this interpretation corroborated by the low b-values that suggest high differential stresses for these fault segments.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2023.00012023-02-17T00:00:00.000+00:00https://sciendo.com/article/10.17738/ajes.2023.0004<abstract> <title style='display:none'>Abstract</title> <p>The middle Miocene Warukin Formation in the Asem-Asem Basin (Kalimantan) contains a 20-m-thick coal seam (BL1) that is mined at the Jumbang mine. The seam, formed in a tropical peat, was studied to reconstruct the peat-forming environment and to compare its characteristics with those of similarly aged tropical coals from the Tutupan mine in the Barito Basin (Kalimantan) and similarly aged (^~15 Ma) subtropical coal from the Leoben Basin in the Eastern Alps (Austria). Although all coals were formed in ombrotrophic peatlands, the comparison reveals differences in biomarker and maceral composition due to the different climate and flora.</p> <p>The study is based on 22 coal and three non–coal samples, each representing a stratigraphic interval of 0.2 to 1.0 m. The samples were analyzed for ash yield, carbon and sulphur contents, and maceral composition. Organic geochemical parameters were obtained on eight coal samples to obtain information on the peat-forming vegetation. The low-ash, low-sulphur BL1 seam was deposited in an ombrotrophic basinal (coastal) mire. Locally increased sulphur contents in the lower coal bench BL1L demonstrate brackish influence and a near-shore environment. The vegetation was dominated by angiosperms including abundant dammar resin producing <italic>Dipterocarpaceae</italic>, while the contribution of gymnosperms was negligible.</p> <p>The Tutupan seams T110 and T210, which were formed in kerapah (inland) ombrotrophic mires, have similar ash yields and sulphur contents but contain higher, although still low, concentrations of gymnosperm-derived diterpenoids. In addition, lower amounts of cadinane-type biomarkers and resinite suggest that <italic>Dipterocarpaceae</italic> were less dominant in kerapah peats. While differences between tropical coals from Kalimantan are minor, major differences exist between the tropical coals and the subtropical ombrotrophic Leoben coal. These include significantly higher concentrations of gymnosperm-derived biomarkers in subtropical peat, lower amounts of resinite due to the absence of <italic>Dipterocarpaceae</italic>, as wells as lower amounts of leaf- and rootlet-derived macerals. Apparently, fungal activity was also reduced in the sub-tropical Leoben peat. Surprisingly, the average amount of oxidized plant remains is also lower in the subtropical peat.</p> </abstract>ARTICLEtruehttps://sciendo.com/article/10.17738/ajes.2023.00042023-05-16T00:00:00.000+00:00en-us-1