10 research outputs found
Repeated change from crustal shortening to orogen-parallel extension in the Austroalpine units of Graub"unden
No full textThe structural analysis of the Austroalpine units in Graubunden reveals the existence of two orogenic cycles, Cretaceous and Tertiary in age, both including thrusting followed by extensional overprint. Such extensional faulting occurred in the Late Cretaceous and in the Early to Mid-Oligocene. In both episodes, the direction of extension was parallel to the strike of the Alpine chain. Five stages of the tectonic evolution are described. The recognition of two orogenic cycles contradicts the classical view that the Alpine orogeny involves a continuous tectonometamorphic evolution from Cretaceous subduction and high-pressure metamorphism to Tertiary exhumation and Barrow-type metamorphism. Instead, it is postulated that nappe formation related to subduction and exhumation associated with extension occurrred twice during the Alpine orogeny. -from Author
Torque measurements and flowvisualisations in a wide gap Taylor-Couette flow
No full textThe Torque acting on the inner cylinder in a differentially rotating Taylor-Couette flow is investigated. In the past a torque maximum has been found in the counter rotating regime. Using flow visualisations and LDA measurements a deeper look inside the flow in the vicinity of this maximum will be done
Experimental investigation of Taylor-Couette flow with radius ratio 0.1 to 0.3
No full textTurbulent flow of a very wide Taylor Couette flow (radius ratio 0.1 up to 0.3) is the scope of the present work. Flow visualisation shows the existing coherent structures. Laser Doppler Velocimetry is used to analyse the local velocity behaviour and understand the flow in this geometry
Magnetresonanztomographisch gestützte Subtypisierung von Glioblastomen und Korrelation mit dem MGMT-Status und dem Gesamtüberleben
No full textZiel dieser Untersuchung sollte die Erhebung eines Imaging Biomarkers zur nicht-invasiven und schnellen Abschätzung der Prognose von Glioblastompatienten sein. Hierzu erfolgte die detaillierte visuelle Analyse des Kontrastmittenanreicherungsverhaltens der Tumoren im MRT im Hinblick auf die Konstrastmittelmorphologie von neu diagnostizierten Glioblastomen. Mit dieser Studie ist es gelungen, anhand einfach zu erhebender bildmorphologischer Parameter Glioblastome im kontrastmittelgestützten MRT in vornehmlich zwei visuell unterscheidbare Kategorien einzuteilen, einen rahmenförmigen und einen palisadenförmigen Kontrastmittel-Phänotyp. Eine einfache Integration in den klinischen Alltag ist gegeben, da die Auswertung auf einer T1 gewichteten post-Kontrastmittel Sequenz, die eine Standardsequenz bei der Untersuchung von Patienten mit Verdacht auf ein Glioblastom darstellt, basiert. Zudem können die Kriterien relativ schnell gelernt werden, sodass die Einteilung eines Tumors in den meisten Fällen auf den ersten Blick erfolgen kann und weder langwierige, manuelle Markierungen bestimmter Areale, noch zeitaufwändige computergestützte Algorithmen von Nöten sind. Obwohl die Anwendung dieser Kategorien mit vergleichsweise wenig Arbeitsaufwand verbunden ist, wies sie in der Testgruppe eine statistisch signifikante Aussagekraft hinsichtlich des medianen Gesamtüberlebens der Patienten auf. Erwiesen sich die erhobenen Kategorien auch als eigenständige und unabhängige Prognosefaktoren ohne Korrelation mit bekannten Markern, wie der MGMT-Promotermethylierung oder dem Karnofsky Performance Score, so lässt dies doch zur selben Zeit Raum für weitere Forschung bezüglich der Ursachen für die verschiedenen Anreicherungsformen und ihrer Verbindungen zu anderen molekularpathologischen Markern oder Signalwegen. Eventuelle Ergebnisse aus solchen Untersuchungen könnten weitere Anwendungsmöglichkeiten der Kategorisierung nicht nur zur Prognoseeinschätzung, sondern auch bezüglich der Vorhersage von Erfolgswahrscheinlichkeiten bestimmter Therapien oder Ansätze für neue Therapieverfahren liefern. Somit liefert diese Arbeit nicht nur ein nützliches, gut in den Alltag integrierbares Tool zur Einschätzung der Prognose eines Patienten mit Glioblastom, das als Richtungsweiser bei der Wahl des weiteren Vorgehens bzw. der Therapie genutzt werden kann, sondern legt auch den Grundstein für weitere Forschungsprojekte hinsichtlich der Ursachen der bildmorphologischen Heterogenität von Glioblastomen
Unusual location of recurrent mantle cell lymphoma on fluorodeoxyglucose-positron emission tomography despite complete metabolic resolution of previous sites of disease
No full textThis case report presents a patient with recurrent pleomorphic mantle cell lymphoma (MCL), which is a relatively rare but aggressive type of lymphoma. A positron emission tomography/computed tomography scan performed to assess treatment response demonstrated a complete metabolic response in the sites of primary disease while also revealing new subcutaneous lesions, which were biopsy-proven recurrent disease. This case illustrates the importance of the different biological behavior of MCL, whereby new sites of metabolically active lesions can represent recurrent disease, even though there is a complete metabolic response at sites of primary disease
A geological 3D-model of Austria
No full textGeoSphere Austria (formerly Geologische Bundesanstalt - Geological Survey of Austria) has produced a supra-regional 3D framework model called “3D AUSTRIA” providing a large-scale geological overview for professional geologists, students and the public. This model is intended to act as support for subsequent regional modelling projects as well as for educational and communicational purpose.
The modelled domain of covers a rectangular area of 175 000 km² including the national borders of Austria, down to a depth to 60 km below sea level. Model units are defined following the nomenclature of Schmid et al. (2004) and Froitzheim et al. (2008), each unit having a specific paleo-geographic origin and tectono-metamorphic history. Seven modelling units are considered: two continental plates (1) the Adriatic Plate, (2) the Eurasian Plate, four units from the Alpine orogenic wedge (3) the South-Alpine Superunit, (4) the Austroalpine Superunit, (5) the Penninic Superunit, (6) the Sub-Penninic Superunit and (7) Neogene sedimentary basins in the foreland and within the Alps. Due to the large-scale character of the model, relatively small constituents of the Alpine Orogen are merged together (Meliata Superunit and Inner Western Carpathian Superunit with the Austroalpine Superunit, Helvetic Superunit and Allochtone Molasse with the Sup-Penninic Superunit, intrusive rocks along the Periadriatic Fault with their host unit, minor Neogene basins with the Austroalpine Superunit). The model geometry is constrained by the geological map of Austria 1:1.5M (Schuster et al., 2019), (2) 24 published cross sections and (3) published contour maps for the Moho discontinuity (Ziegler & Dèzes, 2006) and the large Neogene basins. It has been generated with the SKUA-GOCAD software suite following the workflow of Pfleiderer et al. (2016).
The framework model 3D AUSTRIA can be visualized with the web 3D Viewer of Geosphere Austria (https://gis.geosphere.at/portal/home/webscene/viewer.html?webscene=c11cd25795294ba8b6f276ab2d072afb) or downloaded from the Tethys Research Data Repository (https://doi.tethys.at/10.24341/tethys.184) allowing the generation of a physical multi-part model using 3D printing technology. It provides a unique way to comprehend the fundamentally 3D nature of sedimentary and tectonic features, like the unconformity at the base of Neogene sedimentary basins, the Alpine frontal thrust or the Tauern Window. The data acquired in the framework of the AlpArray project can be used in future for refining the geometry of 3D AUSTRIA
Ground-based geological mapping integrated by UAs in the Chiavenna area (Central Alps): examples of application in the frame of the CARG project
No full textGround-based geological mapping integrated by UAs in the Chiavenna area (Central Alps):
examples of application in the frame of the CARG project
Tartarotti P.*1, Apuani T.', Arrigoni F.', Conforto A.', Pigazzi E.', Tantardini D.' & Toffolon G.?
1 Dipartimento di Scienze della Terra
"A. Desio", Università di Milano. 2 Contractor CARG-Valchiavenna Project.
Corresponding author e-mail: [email protected]
Traditional ground-based mapping of cry stalline basements is essential to unravel their tectono-metamorphic
evolution. However, the structural setting of metamorphic terranes is most of the time complicated by the
polyphase history, not least by neotectonics. Many scientific difficulties can be overcome by implementing
the field work with analytical investigations, such as chemical or geochronological analyses, that may solve
several geological issues as long as the structural and microstructural features are well constrained. Recently, an
interest has been growing in advanced technologies dedicated to data acquisition and applications in geological
mapping. Nowadays, unmanned aerial systems (UASs) such as drones are more and more utilised, especially
in mineral exploration and mine exploitation (.g., Honarmand & Shahriari, 2021). Drone photogrammetry
is particularly useful in inaccessible areas, opening a new perspective for all kinds of ground operators. We
used DJI Mavic 2 Pro and DJI Mavic Mini drones to implement the traditional field work on crystalline
basements in the Chiavenna area (Central Alps), within the frame of the project '
"Carta Geologica d'Italia
at scale 1:50.000 - CARG', covering ca. 700 kmq. This area is characterized by altitudes ranging between
200 and 3300 m a.s.l., and by a hostile topography with steep slopes and few road access that make many
outcrops scarcely or not reachable. Most of the territory sees the exposure of polymetamorphic basements of
the Penninic Suretta, Tambò, and Adula Nappes, separated by sheets of Mesozoic metasedimentary rocks, the
Chiavenna unit, interpreted as a remnant of the Valais Ocean, and the Gruf Complex, whose attribution is still
uncertain, intruded in the southeastern portion by the Bergell pluton (Schmid et al., 1996). UAS tools turn to
be fundamental in such kind of terrains, whose applications regard the recognition of different lithologies on
exposed surfaces, structures, morphologies, and landslides. Reiteration of field and intermediate laboratory
work, with UAS-assisted surveys is necessary to finalise the geological mapping and its interpretation.
Honarmand M. & Shahriari H. (2021) - Geological Mapping Using Drone-Based Photogrammetry: An Application for
Exploration of Vein-Type Cu Mineralization. Minerals, 11(6), 585.
Schmid S. M., Pfiffner O. A., Froitzheim N., Schönborn G. & Kissling E. (1996) - Geophysical-geological transect and
tectonic evolution of the Swiss-Italian Alps. Tectonics, 15(5), 1036-1064
Thermal and structural evolution of the East Carpathians in northern Romania : from Cretaceous orogeny to final exhumation during Miocene collision
No full textCombining thermochronological methods with structural field data, this study aims to reconstruct the Tertiary burial and exhumation history of the northeastern part of the Tisza‐ Dacia block during its invasion in the Carpathian embayment and final soft collision with the European margin. Zircon fission track data additionally provide information about the last metamorphic overprint during the Cretaceous. Within the basement units of the northern Central East Carpathians (Bucovinian nappe stack) and the Preluca massif (Biharia unit) zircon fission tracks are largely reset during the last (Cretaceous) orogeny. Temperatures during this Alpine metamorphic overprint increase from external to internal within the northern East Carpathians from sub‐greenschist facies conditions to at least greenschist facies conditions. Greenschist facies conditions are also observed in the Preluca massif. The close neighbourhood of Coniacian to Campanian zircon FT cooling ages with Cenomanian sediments suggests Late Cretaceous tectonic exhumation in the northern East Carpathians. The most likely explanation for this tectonic exhumation is a ‐ so far undocumented ‐ Late Cretaceous extension related to orogenic collapse (Gosau type basins). The Tertiary evolution is characterised by the invasion of the previously amalgamated Tisza‐Dacia and ALCAPA blocks into the Carpathian embayment and Miocene soft collision of both these blocks with the European margin. The juxtaposition of the ALCAPA and Tisza‐Dacia blocks, with Tisza‐Dacia in a lower plate position, is announced by the onset of Oligocene turbiditic sedimentation. The Burdigalian SE‐directed over‐thrusting of the Pienides (non‐ metamorphic flysch units) is interpreted to express the final stages of this juxtaposition. Burial heating caused full annealing of fission tracks in apatite (i.e. >120°C) in the Central East Carpathian basement in the NE of the study area, while in the basement of the Preluca massif in the SW of the study area temperatures related to Paleogene to Early Miocene burial did not exceed 80°C. The post‐Burdigalian (post‐16 Ma) soft collision of Tisza‐Dacia with the European margin occurred in two stages expressed by predominantly sinistral strike‐slip deformation during constant NE‐SW shortening. During and following soft collision, combined uplift and erosion caused exhumation of the buried rocks along the European margin. Uplift reaches up to 9 km in the Rodna horst The first post‐Burdigalian transpressional stage (16‐12 Ma) is related to perpendicular convergence of Tisza‐Dacia with the NW‐SE striking European margin. Minor exhumation during this stage resulted in Middle Miocene apatite fission track cooling ages (15‐13 Ma) in the west of the study area. The transtensional stage (12–10 Ma) led to the formation of the Bogdan‐Dragos‐Voda fault system. Sinistral transtension allowed for the docking and fitting of Tisza‐Dacia with the NW‐ SE striking European margin. Oblique E‐W convergence led to strain partitioning with thrusting in the external thrust belt and internal strike‐slip deformation. Differential lateral movements are distributed and deformation is accommodated by E‐W striking sinistral strike slip faults and SW‐NE striking normal faults, which led to fragmentation into SW‐tilted blocks. Fragmentation and differential offset along the bounding faults resulted in the formation of triangular‐shaped graben and corresponding horst structures. Enhanced exhumation during transtensional activity led to advective heat transport and resulted in Middle to Late Miocene apatite fission track cooling ages (13‐7) in the east of the study area
Terawatt-scale photovoltaics: Trajectories and challenges
No full textCoordinating technology, policy, and business innovations</jats:p
Seismic structure of the continental margin of French Guiana: implications for the rifting and early spreading of the equatorial Atlantic
No full textRecent studies of passive continental margins suggest that the rifting process produces a variety of structural styles. The along-strike continuity of these rifted margins is punctuated by significant lateral offsets, known as transform margins. Whilst many general features of both rift- and transform-style margins have been identified, the extent to which they are inter-related is not well understood. The equatorial Atlantic exhibits a high number of large offset mid-ocean ridge transform faults and associated fracture zones, which indicate the highly segmented nature of its margins. As such, this location provides an ideal setting for a study of the deep structure of both rift- and transform-style margin structures. This investigation forms part of the Amazon Cone Experiment, a large-scale geophysical study of the French Guiana and northeast Brazil margin in the west equatorial Atlantic. This study will provide evidence of crustal structure from recently acquired seismic, gravity and magnetic data, along two transects of the margin. The acquisition comprised 962 km of coincident multi-channel reflection and wide-angle refraction seismic data which were recorded by 20 ocean-bottom seismographs per transect, deployed at 10 km spacing. Ray-trace forward modelling of traveltime data from these instruments has resulted in two P-wave velocity-depth models of the subsurface structure which have been tested and further constrained by independent gravity free-air anomaly data. Interpretation of the resulting models suggests that the pre rift continental crust is 35- 37 km thick. While at the oceanward end or each transect oceanic crust is identified which, at 3.5-5.0 km thickness, is considered to be unusually thin. The manner in which this transition is accomplished is dramatically different between the two models. In the south of the survey area the crust thins abruptly by a factor of 6.4 over a distance of ~70 km, adjacent to a ~ 45 km ocean-continent transition zone. To the north, however, more gradual thinning over ~ 320 km associated with an abrupt transition to oceanic crust is observed. Neither profile shows evidence of the tilted fault blocks characteristic of rifted margins. There is no evidence for rift-related magmatism, commonly manifest as high P- wave velocity underplating or packages of seaward-dipping reflectors, along either profile. Hence, the margin is interpreted as non-volcanic, which suggests that rifting was not very rapid. On the basis of these results, a model of transtensional rifting is proposed, in which a component of motion oblique to the margin results in the production of relatively wide, leaky' transform margins. This model suggests that the French Guiana margin is segmented into rift- and transform-style structures. However, the transform margins exhibit unusually wide zones of continental crustal thinning as a result of the transtensional extension. For the Amazon Cone Experiment as a whole, anomalously thin oceanic crust is observed over a wide areal extent. This crust indicates that magma flow from the mantle is low and is interpreted to be a result of relatively cool asthenospheric mantle, slow spreading and the effect of large-scale fracture zones. The results of this study have implications for our understanding of the effects of transtensional stresses during rifting and mode of opening of the equatorial Atlantic
