Apport de la modélisation 3D et de la restauration structurale dans la compréhension des gisements de matières premières minérales

Université de Lorraine

Abstract

The objective of this Ph.D. thesis is to apply 3D and 4D modeling methods to reconstruct the architecture and deformations over time of geological entities in a defined region. Structural restoration modeling is used here to estimate geological, physical and structural attributes for understanding the origin of ore-deposits, and for identifying potential mineralized areas. We focused this thesis on 3D and 4D modeling on real case studies with different geological contexts (e.g. uplifting, fault activity and shortening), demonstrating the advantages and drawbacks on their use for similar situations. This thesis is organized into three parts: (i ) The application of structural modeling in the mining district of the opper Belt of Legnica-Glogow (south-west Poland) . A surface-restoration approach was applied to estimate favorable conditions for hydraulic fracturing during an inversion, occurred in the northern part of Europe at Late Cretaceous–Early Paleocene. In our hypothesis, hydraulic fracturing developed at that time played an important role in the distribution of copper content observed in present days in the mining district. (ii ) The curvature calculated on triangulated surfaces that represent the stratigraphic horizons in the Fore-Sudetic region (Poland), are used to highlight the fault systems in the basement as well as their activity. High curvature values reveal the fault activity which is associated with the copper mineralization process in the region. (iii) Mechanical restoration of the Mount Pleasant, Western Australia, simulates an Archean shortening event which occurred in the area linked to the gold mineralization process. The mechanical restoration was used to estimate the strain field in the region at the time of shortening. This deformation field was used to estimate the damage parameters of the rock mass. They show new potential gold areas located in off-fault gold systems. In conclusion, it is shown that 3D modeling and structural restoration could be used to identify potential favorable zones for the presence of mineralization, and seem promising as a tool for the exploration of ore-deposits and mineral resources.

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BibTeX Reference

@PHDTHESIS{,
    author = { Mejia-Herrera, Pablo },
     title = { Apport de la modélisation 3D et de la restauration structurale dans la compréhension des gisements de matières  premières minérales },
      year = { 2014 },
    school = { Université de Lorraine },
       url = { http://ring.gocad.org/ring_dl/public/publications/2014PhdMejia.pdf },
  abstract = { The objective of this Ph.D. thesis is to apply 3D and 4D modeling methods to reconstruct the architecture and deformations over time of geological entities in a defined region. Structural restoration modeling is used here to estimate geological, physical and structural attributes for understanding the origin of ore-deposits, and for identifying potential mineralized areas. We focused this thesis on 3D and 4D modeling on real case studies with different geological contexts (e.g. uplifting, fault activity and shortening), demonstrating the advantages and drawbacks on their use for similar situations. This thesis is organized into three parts: (i ) The application of structural modeling in the mining district of the  opper Belt of Legnica-Glogow (south-west Poland) . A surface-restoration approach was applied to estimate favorable conditions for hydraulic fracturing during an inversion, occurred in the northern part of Europe at Late Cretaceous–Early Paleocene. In our hypothesis, hydraulic fracturing developed at that time played an important role in the distribution of copper content observed in present days in the mining district. (ii ) The curvature calculated on triangulated surfaces that represent the stratigraphic horizons in the Fore-Sudetic region (Poland), are used to highlight the fault systems in the basement as well as their activity. High curvature values reveal the fault activity which is associated with the copper mineralization process in the region. (iii) Mechanical restoration of the Mount Pleasant, Western Australia, simulates an Archean shortening event which occurred in the area linked to the gold
mineralization process. The mechanical restoration was used to estimate the strain field in the region at the time of shortening. This deformation field was used to estimate the damage parameters of the rock mass. They show new potential gold areas located in off-fault gold systems. In conclusion, it is shown that 3D modeling and structural restoration could be used to identify potential favorable zones for the presence of mineralization, and seem promising as a tool for the exploration of ore-deposits and mineral resources. }
}