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Defining, exploring, imaging and assessing reservoirs for potential heat exchange - Potsdam, Germany, Workshop1
Defining, exploring, imaging and assessing reservoirs for potential heat exchange - Potsdam, Germany, Workshop1
6-8 November 2006 GeoForschungsZentrum Potsdam (GFZ)
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Laterally forced overturns in Variscan belt: a new model of lithological and thermal structure of continental crust
New observations from the European Palaeozoic belt indicate significant material 
transfers, far from plate boundaries, which are incompatible with the current 
concepts of collision tectonics. These material and heat transfer called “laterally 
forced overturns” (LFO) are enhanced by grain-scale melt-induced softening  
reducing significantly the strength of orogenic lower crust. The LFO is 
accomplished by vertical extrusion of the OLC from the bottom of the crustal root 
along steep channels of variable dimension and,  by lateral viscous spreading of 
partially molten OLC in supra-crustal levels. Detailed structural and geophysical 
characterization of LFO records (e.g., vertical and horizontal channel flows) is 
shown in the Variscan orogenic root. This model is suplemented by thermodynamic 
modelling (Thermocalc, Perplex) of PTt evolutions aiming to determine transient 
thermal evolutions of orogenic roots. The thermodynamic modelling is also applied 
to evaluate melting processes as well as the equilibrium between infiltrated melts 
and host rocks. The extruded orogenic lower crust is significantly compositionally 
modified by melt infiltration process, so that it becames more felsic and 
radiogenic.  In addition, the new vertical and horizontal distribution of crustal 
material favour high proportion of felsic material in supracrustal levels and 
melting of buried supracrustal material. It will be shown, how the vertical 
material transfer process modify the radiogenic heat production, thereby 
influencing possible heat flow pattern in Varszican orogenic belt.
Id: 44
Place: GeoForschungsZentrum Potsdam (GFZ)
14473 Potsdam, Telegrafenberg
Starting date:
06-Nov-2006   09:30
Duration: 25'
Contribution type: Talk
Primary Authors: Prof. SCHULMANN, Karel (EOST Strasbourg)
Presenters: Prof. SCHULMANN, Karel
Material: slides Slides

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