Predicting off-fault gold potential using 3D restored strain parameters (Mount Pleasant Area, Western Australia).

Maria Kakurina and Pablo Mejia-Herrera and Jean-Jacques Royer. ( 2015 )
in: 35th Gocad Meeting - 2015 RING Meeting, ASGA

Abstract

A broad variety of gold deposits were formed within fault systems that provide a mineralized fluid with necessary conditions for metal accumulations. However, some gold occurrences are located far from the main faults. In this case, the permeability of the rock mass is caused by internal damage developed during a deformation event. It is possible to model such development using restoration tools and, consequently, to estimate the strain tensor that measures the deformation. This contribution may provide an explanation of such off-fault gold deposits and certain deformation parameters may be used for a new targeting in exploration surveys. In the present research two SKUA-GOCAD restoration methods were applied to the golden-rich Mount Pleasant area in Western Australia and compared afterwards. One of the restoration methods, provided by RestorationLab plugin, is based on the Finite Element method and requires a geomechanical model of the area. Another method, the GeoChron Model, is based on the transformation of the coordinates of the present time to a new curvilinear coordinate system of the depositional time. The resulting strain tensors of both methods were used to calculate different deformation parameters and to estimate their correlation with gold occurrences using logistic regression. Some deformation parameters obtained by RestorationLab approach seems to show higher probability to observe gold deposits; however, the highest correlations with the gold occurrences were achieved with the gradient of the deformation parameter calculated by the GeoChron Model.

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BibTeX Reference

@INPROCEEDINGS{KakurinaGM2015,
    author = { Kakurina, Maria and Mejia-Herrera, Pablo and Royer, Jean-Jacques },
     title = { Predicting off-fault gold potential using 3D restored strain parameters (Mount Pleasant Area, Western Australia). },
 booktitle = { 35th Gocad Meeting - 2015 RING Meeting },
      year = { 2015 },
 publisher = { ASGA },
  abstract = { A broad variety of gold deposits were formed within fault systems that provide a mineralized fluid with necessary conditions for metal accumulations. However, some gold occurrences are located far from the main faults. In this case, the permeability of the rock mass is caused by internal damage developed during a deformation event. It is possible to model such development using restoration tools and, consequently, to estimate the strain tensor that measures the deformation. This contribution may provide an explanation of such off-fault gold deposits and certain deformation parameters may be used for a new targeting in exploration surveys. In the present research two SKUA-GOCAD restoration methods were applied to the golden-rich Mount Pleasant area in Western Australia and compared afterwards. One of the restoration methods, provided by RestorationLab plugin, is based on the Finite Element method and requires a geomechanical model of the area. Another method, the GeoChron Model, is based on the transformation of the coordinates of the present time to a new curvilinear coordinate system of the depositional time. The resulting strain tensors of both methods were used to calculate different deformation parameters and to estimate their correlation with gold occurrences using logistic regression. Some deformation parameters obtained by RestorationLab approach seems to show higher probability to observe gold deposits; however, the highest correlations with the gold occurrences were achieved with the gradient of the deformation parameter calculated by the GeoChron Model. }
}