3D Geological Modelling of Faulted Crystalline Basement Rocks (Poehla- Tellerhaeuser Ore Field, Ore Mountains, Germany)

Peter Achtziger-Zupančič and S. Loew and Axel Hiller. ( 2016 )
in: 2016 RING Meeting, ASGA

Abstract

Groundwater flow in fractured basement rocks on aquifer scale and processes involved in the creation of fracture network permeability are poorly understood even though they have been studied for decades. As a basis for statistical analyses of preferential water flow in faulted basement rocks, the Poehla- Tellerhaeuser Ore Field (Ore Mountains/Germany) has been modelled geologically in 3D. This geological model is based on numerous detailed cross sections, geologic surface and underground level maps stored at the archive of the Wismut GmbH and at the Saxon State Agency for Geology, Agriculture and Environment. The model of the Variscan basement covers a volume of 14x4x1 km 3 with 14 metamorphosed litho-stratigraphic units and 131 faults separated in 6 main strike directions. The model explicitly considers trace length (extent), displacement and width of core and damage zones of 31 faults, which were identified to control the block structure of the Ore Field by exhibiting geometrical mean displacements larger than 10 m. As the faults at Poehla-Tellerhaeuser Ore Field were repeatedly reactivated, the fault network is very dense and presumably in a mature state. The faults have the tendency for simple planar geometries and are assumed to have a symmetrical architecture consisting of fault core, damage zone and protolith. On average, fault zone coverage in the investigated volume is very high, around 90%, and in most places several damage zones overlap. The area covered by fault core and the area covered by multiple overlapping fault zones decrease with depth expressing fewer destruction with increasing depth. Most intensively destructed rock masses host the main orebodies which usually follow the major fault zones controlling the structural damage of the rock mass.

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BibTeX Reference

@INPROCEEDINGS{,
    author = { Achtziger-Zupančič, Peter and Loew, S. and Hiller, Axel },
     title = { 3D Geological Modelling of Faulted Crystalline Basement Rocks (Poehla- Tellerhaeuser Ore Field, Ore Mountains, Germany) },
 booktitle = { 2016 RING Meeting },
      year = { 2016 },
 publisher = { ASGA },
  abstract = { Groundwater flow in fractured basement rocks on aquifer scale and processes involved in the creation
of fracture network permeability are poorly understood even though they have been studied for decades.
As a basis for statistical analyses of preferential water flow in faulted basement rocks, the Poehla-
Tellerhaeuser Ore Field (Ore Mountains/Germany) has been modelled geologically in 3D.
This geological model is based on numerous detailed cross sections, geologic surface and underground
level maps stored at the archive of the Wismut GmbH and at the Saxon State Agency for Geology,
Agriculture and Environment. The model of the Variscan basement covers a volume of 14x4x1 km 3 with
14 metamorphosed litho-stratigraphic units and 131 faults separated in 6 main strike directions. The model
explicitly considers trace length (extent), displacement and width of core and damage zones of 31 faults,
which were identified to control the block structure of the Ore Field by exhibiting geometrical mean
displacements larger than 10 m.
As the faults at Poehla-Tellerhaeuser Ore Field were repeatedly reactivated, the fault network is very
dense and presumably in a mature state. The faults have the tendency for simple planar geometries and are
assumed to have a symmetrical architecture consisting of fault core, damage zone and protolith. On average,
fault zone coverage in the investigated volume is very high, around 90%, and in most places several damage
zones overlap. The area covered by fault core and the area covered by multiple overlapping fault zones
decrease with depth expressing fewer destruction with increasing depth. Most intensively destructed rock
masses host the main orebodies which usually follow the major fault zones controlling the structural damage of the rock mass. }
}