Using strain parameters from 3D restoration to estimate distant off-fault gold potentials, Mount Pleasant Area, Western Australia

Pablo Mejia-Herrera and Maria Kakurina and Jean-Jacques Royer. ( 2014 )
in: Proc. 34th Gocad Meeting, Nancy, ASGA

Abstract

A broad variety of gold-deposits are related to fault systems developed during a deformation event. Such discontinuities control the metals transport and allow the relatively high permeability necessary for the metals accumulation during the ore-deposits formation. However, some gold deposits formed during the same deformation event occur at locations far from the main faults. In those cases, the fracture systems are related with the rock heterogeneity that partially controls the damage development on the rock mass. We used geomechanical restoration to simulate the strain developed during a stretching episode occurred in the Mount Pleasant region, Western Australia, and show how the rock heterogeneity allows damage in locations far from the fault systems. The distant off-fault damage areas are located preferentially in lithological contacts and also follow the deformation trend of the region. We show that off-fault zones with high gold occurrences correlate spatially on locations with locally-high-gradient first deformational parameter, obtained from the restoration strain field. This contributions may go some way provide the explanation for the presence of gold accumulations away from main fault systems, and the method could be used for inferring favorable areas in exploration surveys.

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BibTeX Reference

@INPROCEEDINGS{,
    author = { Mejia-Herrera, Pablo and Kakurina, Maria and Royer, Jean-Jacques },
     title = { Using strain parameters from 3D restoration to estimate distant off-fault gold potentials, Mount Pleasant Area, Western Australia },
     month = { "sep" },
 booktitle = { Proc. 34th Gocad Meeting },
      year = { 2014 },
 publisher = { ASGA },
  location = { Nancy },
  abstract = { A broad variety of gold-deposits are related to fault systems developed during a deformation event. Such discontinuities control the metals transport and allow the relatively high permeability necessary for the metals accumulation during the ore-deposits formation. However, some gold deposits formed during the same deformation event occur at locations far from the main faults. In those cases, the fracture systems are related with the rock heterogeneity that partially controls the damage development on the rock mass. We used geomechanical restoration to simulate the strain developed during a stretching episode occurred in the Mount Pleasant region, Western Australia, and show how the rock heterogeneity allows damage in locations far from the fault systems. The distant off-fault damage areas are located preferentially in lithological contacts and also follow the deformation trend of the region. We show that off-fault zones with high gold occurrences correlate spatially on locations with locally-high-gradient first deformational parameter, obtained from the restoration strain field. This contributions may go some way provide the explanation for the presence of gold accumulations away from main fault systems, and the method could be used for inferring favorable areas in exploration surveys. }
}