Paleostress and kinematic evolution of the orogen-parallel NW-SE striking faults in the NW External Dinarides of Slovenia unraveled by mesoscale fault-slip data anaysis

The late Eocene to Recent dynamics of the NW External Dinarides in Slovenia are described. The study is focused on the orogen-parallel NW-SE striking family of faults, which represent the main source of seismic hazard in the NW External Dinarides today. Approximately 1700 fault-slip datasets were collected at 70 locations and used for palaeostress analysis. Structural relationships observed in the field, allowed the construction of a relative chronology between the documented fault and shear joint sets, facilitating the reconstruction of their kinematic evolution and the chronology of palaeostress phases. Four post-Palaeocene stress tensor groups are documented corresponding to four distinct tectonic phases. The first phase is marked by NE-SW directed compression attributed to Late Eocene top-to-SW thrusting of External Dinarides. The second phase is characterized by NE-SW oriented tension, documented by normal slips recorded on NW-SE striking faults. This tension is interpreted as an expression of the Early to Middle Miocene back-arc extension in the Pannonian basin system that also affected the studied part of the External Dinarides. The third phase is manifested by approximately E-W oriented compression with approximately N-S oriented tension in a strike-slip stress regime, causing sinistral reactivation of NW-SE trending faults. Geodynamically, this phase can be correlated with the Late Miocene short pulse of E-W directed compression, documented in parts of the Pannonian basin system. The youngest phase is characterized by approximately N-S oriented compression and approximately E-W oriented tension in a strike-slip stress regime, which caused dextral reactivation of NW-SE striking faults. This phase correlates with the recent inversive/transpressive phase, well-established from seismological data.</p

Events of ductile and brittle deformations and paleomagnetic rotations within a few million years interval in the Pohorje area, Slovenia

We reconstructed the deformation history of the Pohorje pluton, related subvolcanic rocks and surrounding sediments in NE Slovenia. We used classical field structural measurements, microtectonic observations in thin sections, and various approaches of paleomagnetism. In particular, we compared the main directions of deformation and the main axis of the anisotropy of magnetic susceptibility (AMS). We extended and reinterpreted our existing data base (Márton et al., 2004). The granodioritic-tonalitic Pohorje pluton suffered ductile deformation in the greenschist-facies, which is recorded in both AMS and structural microfabric characteristics. The D1 deformation shows varying styles: extensional in the southern (S) and strike-slip type in the northern part (N) of the pluton. Sub-horizontal (S) and steep foliation (N) is well developed whereas ENE–WSW (S) and SSE–NNW (N) lineation are recorded by stretched minerals and K1 AMS axis (Fig. 1). This deformation occurred just after intrusion at 18.6 Ma, during the imminent cooling of the plutonic rocks (Fodor et al. 2008). After this event, the pluton underwent ca. 70° clockwise rotation, which predates the deposition of Karpatian (17.3 Ma) sediments. During the CW rotation, and slightly after, at ca. 18-17 Ma, the pluton was intruded by diverse, mostly andesitic and aplitic dykes. The AMS indicates minor ca. E–W directed extension, which is sub-perpendicular to the dykes themselves. At the same time, the Karpatian sediments suffered early deformation while they were still in horizontal position. NE–SW or E–W extension was recorded by AMS, and also by pre-tilt normal faults associated with macroscopically ductile fault-related folding. Finally, the last event D3 of ca. 17-15 Ma could be the intrusion of subvolcanic dacitic dykes which show very slight magnetic anisotropy corresponding to dyke emplacement. Later it was followed by 35° counterclockwise rotation

Sediment infill of the Middle Triassic half-graben below Mt. Vernar in the Julian Alps, Slovenia

A sediment infill of a small, late Anisian–earliest Ladinian half-graben, sealed by massive limestone of the Schlern Formation is exposed on the northeastern slopes of Mt. Vernar in the eastern Julian Alps, Slovenia. The pre-rift base of the succession is formed by a chaotic mixture of massive limestone and limestone breccia of the Anisian platform. Sedimentation in the half-graben started with a 20 m thick thinly bedded pink nodular limestone which is informally named here as the Vernar member. It consists of microbial carbonate and was probably deposited within the photic zone. The Vernar member is overlain by poorly sorted polymict breccias of the Uggowitz Breccia Formation which reaches a thickness of at least 150 m, but pinches out rapidly towards the SE graben margin, reflecting the highly asymmetric basin geometry. Individual beds of breccia represent successive debris flow deposits. The Uggowitz Breccia Formation is followed by a few metres of sandstone and sandy limestone of the Buchenstein Formation. The limestone contains abundant grains of shallow marine origin and terrestrial plant fragments. The overlying post-rift Schlern Formation consists of crudely bedded and massive limestone, covering the graben. The consistent NE-SW strike of the graben-bounding faults and of the smallscale conjugate normal faults observed in the Uggowitz Breccia Formation suggests that the half-graben originated from NW-SE directed extension

Posjetitelj mora biti "uvučen" u priču

Važno je napraviti dobre pripreme, upoznati se s materijalom – izlošcima, te organizirati kvalitetan tim ljudi. Najučinkovitijim se pokazalo da jedna osoba, tj. art direktor ili kreativni direktor izložbe, drži pod kontrolom finalni rezultat i da zna usmjeravati suradnike kako bi izložba bila konzistentna u svim elementima – od vizualnog identiteta i dizajna kataloga do signalizacije i ostalih prostornih intervencija. Svaki je detalj bita

Quaternary Seismic Slip in the Eastern Alps: Dating Fault Gouges from the Periadriatic Fault System Using Trapped Charge Dating Methods

The Periadriatic Fault System (PAF) is among the largest post-collisional structures of the Alps. Recent studies using GPS velocities suggest that Adria-Europe convergence is still being accommodated in the Eastern Alps. However, according to instrumental and historical seismicity records, earthquake activity is mostly concentrated along structures in the adjacent Southern Alps and adjacent Dinarides. Apart from ambiguous historical events, the PAF has little to no earthquake record. Electron spin resonance (ESR) and Optically Stimulated Luminescence (OSL) are dating methods that can be applied as ultra-low temperature thermochronometers (closing temperature below 100 °C), with a Quaternary dating range of a few decades up to ~2 Ma. Both are potentially applicable to date shear heating during earthquakes in slowly deforming fault zones. Since the saturation dose of the quartz ESR signals is larger than that of quartz and feldspar OSL, ESR enables establishing a maximum age of the events (assuming the resetting during seismic events was at least partial), while OSL allows finding their minimum age when the signal is in saturation. We analyzed fault gouge samples from 4 localities along the easternmost segment of the PAF (east of the Giudicarie Fault), and 5 localities along the southernmost segment of the Lavanttal Fault. For ESR, we measured the signals from the Al center in quartz, comparing the results from the single aliquot additive dose (SAAD) and single aliquot regenerative dose (SAR) protocols. Different grain size fractions were measured (SAR protocol) to establish a grain-size age plateau. For OSL, we measured the Infrared Stimulated Luminescence (IRSL) signal at 50 °C (IR50) and the post-IR IRSL signal at 225 °C (pIRIR225) on potassium feldspar. Additionally, experiments of thermal activation of the OSL signal in quartz were performed to observe the shear heating effect in different grain size fractions. For the PAF, the OSL shear heating sensitivity experiments show that quartz has been thermally activated to temperatures below 300 °C, corroborating that shear heating was sufficient for at least a partial system reset. The ESR grain size plateaus suggest that the most effectively reset fraction is 100-150 µm. In general, our dating results indicate that the studied segment of the PAF system accommodated seismotectonic deformation within a maximum age ranging from 1075 ± 48 to 349 ± 17 ka (ESR SAR) and a minimum age in the range of 196 ± 12 to 281 ± 16 ka (pIRIR225). The obtained ages and the current configuration of the structure suggest that the studied segment of the PAF could be considered a potentially active fault at least. In the case of the Lavanttal fault, the ESR dose-response curves were either close to or in saturation, allowing to obtain only minimum ages of ca. 4 Ma for the last total reset of the system. This could be the result of insufficient shear heating by low magnitude earthquakes, or the fault has not seen significant activity since then. Altogether, our results show that large structures in the Eastern Alps such as the PAF have accommodated part of the Adria-Europe convergence during the Quaternary and can potentially host earthquakes in the future

Active Tectonics of the Alps-Dinarides junction

The northward motion and rotation of the Adriatic Plate leads to crustal deformation in the Southern Alps and in the Dinarides. Many aspects of the active tectonics in that area have not been properly understood, for example the distribution and localization of strain, the paleoseismic history of the largest faults, the seismic sources for large historical earthquakes, and the landscape record of active faulting. In the framework of SPP2017, we worked in the Southern Alps-Dinarides transition area, encompassing W Slovenia, NE Italy, and S Austria (Fig. 1). We used tectonic geomorphology studies on high-resolution digital elevation models, satellite imagery, field mapping, near-surface geophysics, paleoseismology, and Quaternary dating techniques to understand the pattern of Late Quaternary tectonics. Our results how that in Slovenia, deformation is distributed across a system of major NW-SE striking right-lateral strike slip faults in a more than 60 km-wide zone (Grützner et al., 2021). Many smaller, <15 km long faults show postglacial activity, too. In general, the deformation is widely distributed. In Italy, most of the deformation is accommodated by thrusting at the South Alpine orogenic front. Several thrust faults have stepped out into the Friulian Plain, where they are often blind (Viscolani et al., 2020). Although historical earthquakes with magnitudes larger than M6 occurred in the interior of the mountain chain, instrumental seismicity here is low. There is only very poor geological evidence of fault activity because sedimentation, high erosion rates, and anthropogenic modification dominate the present-day landscape and outpace almost any tectonic signal. In addition, glacial processes have erased most potential evidence for Late Quaternary active tectonics (Diercks et al., 2021, 2022, in press). The situation is similar in Austria, where geological evidence of active faulting is sparse, despite a record of strong historical earthquakes. New dating results from both deformed and undisturbed geomorphic markers allow us to place constraints on the maximum amount of deformation that is accommodated in southern Austria and on fault activity in Slovenia. Our latest results on seismically-triggered mass movements show that the 1348 Earthquake, one of the strongest historical events in the entire Alps, has likely occurred on the Fella-Sava Fault

Re-evaluation of Zospeum schaufussi von Frauenfeld, 1862 and Z. suarezi Gittenberger, 1980, including the description of two new Iberian species using Computer Tomography (CT) (Eupulmonata, Ellobioidea, Carychiidae)

The present study aims to clarify the confused taxonomy of Z. schaufussi von Frauenfeld, 1862 and Zospeum suarezi Gittenberger, 1980. Revision of Iberian Zospeum micro snails is severely hindered by uncertainties regarding the identity of the oldest Iberian Zospeum species, Z. schaufussi von Frauenfeld, 1862. In this paper, we clarify its taxonomic status by designating a lectotype from the original syntype series and by describing its internal and external shell morphology. Using SEM-EDX, we attempt to identify the area of the type locality cave more precisely than "a cave in Spain". The shell described and illustrated by Gittenberger (1980) as Z. schaufussi appears not to be conspecific with the lectotype shell, and is considered a separate species, Z. gittenbergeri Jochum, Prieto & De Winter, sp. n. Zospeum suarezi was described from various caves in NW Spain. Study of the type material reveals that these shells are not homogenous in shell morphology. The holotype shell of Z. suarezi is imaged here for the first time. The paratype shell, illustrated by Gittenberger (1980) from a distant, second cave, is described as Zospeum praetermissum Jochum, Prieto & De Winter, sp. n. The shell selected here as lectotype of Z. schaufussi, was also considered a paratype of Z. suarezi by Gittenberger (1980). Since this specimen is morphologically very similar to topotypic shells of Z. suarezi, the latter species is considered a junior synonym of Z. schaufussi (syn. n.). The internal shell morphology of all these taxa is described and illustrated using X-ray Micro Computer Tomography (Micro-CT).Special gratitude goes to Anita Eschner (NHMW) for helping AJ access the von Frauenfeld collection and for providing valuable insights and primary literature. We are grateful to Markus Heneka and Andreas Heneka (RJL Micro & Analytic GmbH, Karlsdorf-Neuthard) for their help and technical prowess with the CT and SEM-EDX scans. We thank Katharina Jaksch-Mason (NHMW) for LM imaging the Z. schaufussi syntype material. We also gratefully acknowledge Emmanuel Tardy's (MHNG) image contributions and notes of the Gittenberger (1980) material formerly housed in the MHNG collection. Appreciation also goes to Gerald Favre for sharing his excellent forty-year-old speleological field notes with us. We acknowledge Thomas Neubauer and Michael Duda for their kind help in transporting the lectotype back and forth from Vienna. We thank the editor, Thierry Backeljau, the ZooKeys editorial team and our reviewers, Benjamin Gomez, Edmund Gittenberger and Barna Pall-Gergely for their helpful suggestions towards improving the manuscript. Lastly, we are indebted to SYNTHESYS for providing generous support in the form of three grants to AJ from the SYNTHESYS Project http://www.synthesys.info/, which is financed by the European Community Research Infrastructure Action under the FP7 "Capacities" Program

Re-evaluation of Zospeum schaufussi von Frauenfeld, 1862 and Z. suarezi Gittenberger, 1980, including the description of two new Iberian species using Computer Tomography (CT) (Eupulmonata, Ellobioidea, Carychiidae)

The present study aims to clarify the confused taxonomy of Z. schaufussi von Frauenfeld, 1862 and Zospeum suarezi Gittenberger, 1980. Revision of Iberian Zospeum micro snails is severely hindered by uncertainties regarding the identity of the oldest Iberian Zospeum species, Z. schaufussi von Frauenfeld, 1862. In this paper, we clarify its taxonomic status by designating a lectotype from the original syntype series and by describing its internal and external shell morphology. Using SEM-EDX, we attempt to identify the area of the type locality cave more precisely than “a cave in Spain”. The shell described and illustrated by Gittenberger (1980) as Z. schaufussi appears not to be conspecific with the lectotype shell, and is considered a separate species, Z. gittenbergeri Jochum, Prieto &amp;amp; De Winter, sp. n. Zospeum suarezi was described from various caves in NW Spain. Study of the type material reveals that these shells are not homogenous in shell morphology. The holotype shell of Z. suarezi is imaged here for the first time. The paratype shell, illustrated by Gittenberger (1980) from a distant, second cave, is described as Zospeum praetermissum Jochum, Prieto &amp;amp; De Winter, sp. n. The shell selected here as lectotype of Z. schaufussi, was also considered a paratype of Z. suarezi by Gittenberger (1980). Since this specimen is morphologically very similar to topotypic shells of Z. suarezi, the latter species is considered a junior synonym of Z. schaufussi (syn. n.). The internal shell morphology of all these taxa is described and illustrated using X-ray Micro Computer Tomography (Micro-CT)

Groping through the black box of variability: An integrative taxonomic and nomenclatural re-evaluation of Zospeum isselianum Pollonera, 1887 and allied species using new imaging technology (Nano-CT, SEM), conchological, histological and molecular data (Ellobioidea, Carychiidae).

The minute troglobitic species, Zospeum isselianum Pollonera, 1887 (Eupulmonata: Ellobioidea, Carychiidae) is widely distributed within its Southern Alpine-Dinaric range. Its broad distribution and highly variable shell has caused this species to be historically lumped into its current taxonomic state of ambiguity. In an integrative taxonomic approach, phenotypic and genotypic data are synthesized to assess the intraspecific variability recently inferred for this taxon. We collected 16 Zospeum specimens in the Slovenian Alpine Arc encompassing the type locality for Z. isselianum. The material comprises five morphologically recognized (sub)species. The species are re-evaluated using SEM, X-ray nanotomography (nano-CT), conchological, histological and molecular data. Four well-defined lineages are present, which can be attributed to i) Z. isselianum s.str. from its new type locality (Turjeva jama), ii) a highly morphologically variable lineage that so far cannot be attributed to a single morphospecies, iii) Z. kupitzense A. Stummer, 1984 (raised to species rank) and iv) a lineage comprising the two subspecies Z. alpestre alpestre (Freyer, 1855) and Z. alpestre bolei Slapnik, 1991 plus Z. isselianum individuals. The latter is treated as a single taxon Z. alpestre. After considering the severely degraded syntype material of Zospeum isselianum, we provide a taxonomic re-description and propose aneotype for this species. Furthermore, new diagnostic information is revealed regarding the columella of Zospeum isselianum and allied species. Detailed anatomical study reveals new structural aspects of Zospeum morphology and provides groundwork for future investigations

Not another hillshade: alternatives which improve visualizations of bathymetric data

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