Institute of Geophysics of the CAS, v. v. i.

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Orogenic processes

Hoarusib River and Leiland drift, Neoproterozoic zone Kaoko in NW Namibia.

Lithosphere is the outermost solid rock layer of Earth containing continental (0-35 km) or oceanic crust (0-8 km) and the underlying lithospheric mantle. The edges of the tectonic plates are repeatedly undergoing orogenic processes since the Archaic, and those lead to evolution of strongly deformed zones, so called rogenic belts (based on Greek word for the formation of mountains). Each orogeny went through its own development, which includes deformation, metamorphism, magmatism, erosion and sedimentation. Current orogenic zones follow the mountain ranges with distinct topography and reveal processes mainly in the upper parts of orogenic zones. In contrast, the old orogeny are already significantly eroded and makes it possible to study processes in the lower parts of orogens.

Our research is focused on the rheology of naturally deformed rocks from the boundary between continental crust and lithospheric mantle in the deep parts of orogenic zones. For geologist, rheology is study of deformation and viscous flow of rocks under the influence of the applied stress and temperature. The most sensitive indicator of the rock rheological behavior is its microstructure, which is the result of mechanical properties of studied rocks. The main area of ​​interest for our studies is the Bohemian Massif, which represents the largest outcropping area of the Variscan orogenic belt in Europe, although other studies are conducted also in other orogenic zones.


We are currently working on the following topics:

1. Internal deformation structures of upper mantle rocks and their deformational connection with the surrounding quartz-feldspatic rocks in Moldanubian of the Bohemian Massif.
2. Strain structures of the upper mantle rocks and their deformational connection with the surrounding rocks of the Variscan orogeny on the Iberian Peninsula SV Portugal. 
3. Petrophysical properties and rheology of mantle rocks in the mantle and crustal conditions. 
4. Rheology of highly deformed and partially metled quartz-feldspar rocks on the example of granulites from the Bohemian Massif. 
5. Relation between tectonics and repeated magmatic activity (USA?)



Team: Prokop Závada
  Matěj Machek
  Zuzana Roxerová
  Vladimír Kusbach
  Aleš Špičák
  Pavlína Hasalová

This research is being conducted in cooperation with Czech and foreign research teams. Above all, we work with the Institute of Petrology and Structural Geology at the University of Prague, Czech Geological Survey, Ecole et Observatoire des Sciences de la Terre, Université de Strasbourg and the Laboratoire de Tectonophysique, Université de Montpellier in France.

 

 

Erongo, western Namibie