Zr-bearing minerals as indicators for the polymetamorphic evolution of the eastern, lower Austroalpine nappes (Stubenberg Granite contact aureole, Styria, Eastern Alps, Austria)

Lithos ◽  
2007 ◽  
Vol 95 (1-2) ◽  
pp. 72-86 ◽  
Author(s):  
P. Tropper ◽  
D. Harlov ◽  
E. Krenn ◽  
F. Finger ◽  
D. Rhede ◽  
...  
Keyword(s):  
Eastern Alps ◽  
Contact Aureole ◽  
Austroalpine Nappes

Constraining the process of intracontinental subduction: implications from petrology and Lu-Hf geochronology of eclogites from the Austroalpine Nappes

2020 ◽  
Author(s):  
Irena Miladinova ◽  
Nikolaus Froitzheim ◽  
Thorsten Nagel ◽  
Marian Janák ◽  
Raúl Fonseca ◽  
...  
Keyword(s):  
Eastern Alps ◽  
Ultrahigh Pressure ◽  
Garnet Growth ◽  
Published Data ◽  
Isotope Geochronology ◽  
Ultrahigh Pressure Metamorphism ◽  
Austroalpine Nappes ◽  
Short Period ◽  
Facies Metamorphism ◽  
Global Tectonics

<p>The nucleation of subduction zone remains a widely discussed topic in the global tectonics. The prevalent view is that subduction starts within an oceanic plate. However, there is strong evidence that subduction can also be initiated within a continent. To test this hypothesis, we combine petrology, isotope geochronology and thermodynamic phase equilibrium modelling on eclogites from the Austroalpine Nappes of the Eastern Alps.</p><p>The high- and ultrahigh-pressure rocks occur in a ~400 km long belt from the Texel Complex in the west to the Sieggraben Unit in the east without remnants of Mesozoic oceanic crust. Garnet growth during pressure increase was dated using Lu-Hf chronometry. The results range between c. 100 and c. 90 Ma, indicating a short period of subduction. Combined with already published data, our estimates of metamorphic conditions indicate a field gradient with increasing pressure and temperature from northwest to southeast, where the rocks experienced ultrahigh-pressure metamorphism. The oldest Cretaceous eclogites (c. 100 Ma) are found in the Saualpe-Koralpe area which comprises widespread gabbros formed during Permian to Triassic rifting. This supports the hypothesis that subduction initiation was intracontinental and localized by a Permian rift. In the Texel Complex two-phased garnets yielded a Variscan-Eoalpine mixed age indicating re-subduction of Variscan eclogite-bearing continental crust during the Eoalpine orogeny. Jurassic blueschist-facies metamorphism at Meliata in the Western Carpathians and Cretaceous eclogite-facies metamorphism in the Austroalpine are separated by a time gap of ~50 Ma and therefore do not represent a transition from oceanic to continental subduction but rather separate events.</p>

scholarly journals Relocation of earthquakes in the southern and eastern Alps (Austria, Italy) recorded by the dense, temporary SWATH-D network using a Markov chain Monte Carlo inversion

Solid Earth ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 1087-1109
Author(s):  
Azam Jozi Najafabadi ◽  
Christian Haberland ◽  
Trond Ryberg ◽  
Vincent F. Verwater ◽  
Eline Le Breton ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Markov Chain ◽  
Markov Chain Monte Carlo ◽  
Velocity Model ◽  
Eastern Alps ◽  
Inversion Method ◽  
Parameter Uncertainties ◽  
Waveform Data ◽  
Velocity Models ◽  
Austroalpine Nappes

Abstract. In this study, we analyzed a large seismological dataset from temporary and permanent networks in the southern and eastern Alps to establish high-precision hypocenters and 1-D VP and VP/VS models. The waveform data of a subset of local earthquakes with magnitudes in the range of 1–4.2 ML were recorded by the dense, temporary SWATH-D network and selected stations of the AlpArray network between September 2017 and the end of 2018. The first arrival times of P and S waves of earthquakes are determined by a semi-automatic procedure. We applied a Markov chain Monte Carlo inversion method to simultaneously calculate robust hypocenters, a 1-D velocity model, and station corrections without prior assumptions, such as initial velocity models or earthquake locations. A further advantage of this method is the derivation of the model parameter uncertainties and noise levels of the data. The precision estimates of the localization procedure is checked by inverting a synthetic travel time dataset from a complex 3-D velocity model and by using the real stations and earthquakes geometry. The location accuracy is further investigated by a quarry blast test. The average uncertainties of the locations of the earthquakes are below 500 m in their epicenter and ∼ 1.7 km in depth. The earthquake distribution reveals seismicity in the upper crust (0–20 km), which is characterized by pronounced clusters along the Alpine frontal thrust, e.g., the Friuli-Venetia (FV) region, the Giudicarie–Lessini (GL) and Schio-Vicenza domains, the Austroalpine nappes, and the Inntal area. Some seismicity also occurs along the Periadriatic Fault. The general pattern of seismicity reflects head-on convergence of the Adriatic indenter with the Alpine orogenic crust. The seismicity in the FV and GL regions is deeper than the modeled frontal thrusts, which we interpret as indication for southward propagation of the southern Alpine deformation front (blind thrusts).

La protezione dagli incendi boschivi nelle Alpi centro-occidentali | Forest Fire-Prevention in the Central Eastern Alps

2000 ◽  
Vol 151 (9) ◽  
pp. 325-335 ◽  
Author(s):  
Giovanni Bovio
Keyword(s):  
Forest Fire ◽  
Eastern Alps ◽  
Fire Prevention ◽  
Forest Fire Prevention ◽  
Central Eastern

Important forest fire prevention developments of the Lombardy, Piedmont and Aosta Valley regions are highlighted in this study and a certain number of activities considered able to improve the situation are proposed.

The K/T Boundary of Gams (Eastern Alps, Austria) and the Nature of Terminal Cretaceous Mass Extinction

2009 ◽  
Author(s):  
Andrei Grachev ◽  
H. A. Kollmann ◽  
O. A. Korchagin ◽  
D. M. Pechersky ◽  
V. A. Tsel'movich
Keyword(s):  
Mass Extinction ◽  
Eastern Alps
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