Volume 42, Issue 1, March 2024, Pages 22–34
Barkwendé H. Fabrice Ouédraogo1, Pascal Ouiya2, and Boukaré Kiéma3
1 Université Joseph KI ZERBO (UJKZ), Ouagadougou, Burkina Faso
2 Ecole Normale Supérieure (ENS), Ouagadougou, Burkina Faso
3 Ampella Mining Gold Sarl, Burkina Faso
Original language: English
Copyright © 2024 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Mineralization at the Torkera gold deposit is located at the contact between volcanic rocks (basalt-andesite) and volcanosedimentary rocks (pyroclastite, blackshale) in the relay zone within the large West Batié Shear Zone (WBZ). Along strike, these formations are not only strongly sheared, but are also affected by intense hydrothermal fluid circulation. The deposit has not yet been characterized in terms of deformation and hydrothermal alteration. The present study aims to constrain the factors controlling the variation in gold content. Direct field measurements show that the mineralized body contained within the shear zone is affected by two phases of deformation. The first is a shear-type deformation known as D1T, marked by S1T schistosities. This first phase of deformation is taken up by a second phase of deformation called D2T. This second phase is marked by S2T fracture or crenulation schistosity. Two hydrothermal alteration phases affect these formations. The first phase of hydrothermal alteration is a carbonate-chlorite-quartz ± pyrite ± iron oxide paragenesis, while the paragenesis of the second phase of alteration is quartz-pyrite-white mica ± carbonate. Gold mineralization is associated with pyrite crystals from the second phase of hydrothermal alteration, whatever the nature of the host rock. The variation in gold content along the ore body is controlled by the intensity of fluid circulation in relation to deformation. The more space freed up by deformation, the more the hydrothermal fluid interacts with the host rock, resulting in a strong silicification and pyritization phase capable of trapping gold.
Author Keywords: Gold deposit, Torkera, mineralized body, Gold grade.
Barkwendé H. Fabrice Ouédraogo1, Pascal Ouiya2, and Boukaré Kiéma3
1 Université Joseph KI ZERBO (UJKZ), Ouagadougou, Burkina Faso
2 Ecole Normale Supérieure (ENS), Ouagadougou, Burkina Faso
3 Ampella Mining Gold Sarl, Burkina Faso
Original language: English
Copyright © 2024 ISSR Journals. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Mineralization at the Torkera gold deposit is located at the contact between volcanic rocks (basalt-andesite) and volcanosedimentary rocks (pyroclastite, blackshale) in the relay zone within the large West Batié Shear Zone (WBZ). Along strike, these formations are not only strongly sheared, but are also affected by intense hydrothermal fluid circulation. The deposit has not yet been characterized in terms of deformation and hydrothermal alteration. The present study aims to constrain the factors controlling the variation in gold content. Direct field measurements show that the mineralized body contained within the shear zone is affected by two phases of deformation. The first is a shear-type deformation known as D1T, marked by S1T schistosities. This first phase of deformation is taken up by a second phase of deformation called D2T. This second phase is marked by S2T fracture or crenulation schistosity. Two hydrothermal alteration phases affect these formations. The first phase of hydrothermal alteration is a carbonate-chlorite-quartz ± pyrite ± iron oxide paragenesis, while the paragenesis of the second phase of alteration is quartz-pyrite-white mica ± carbonate. Gold mineralization is associated with pyrite crystals from the second phase of hydrothermal alteration, whatever the nature of the host rock. The variation in gold content along the ore body is controlled by the intensity of fluid circulation in relation to deformation. The more space freed up by deformation, the more the hydrothermal fluid interacts with the host rock, resulting in a strong silicification and pyritization phase capable of trapping gold.
Author Keywords: Gold deposit, Torkera, mineralized body, Gold grade.
How to Cite this Article
Barkwendé H. Fabrice Ouédraogo, Pascal Ouiya, and Boukaré Kiéma, “Evolution of gold content along the orebody in the Torkera gold deposit, Gaoua district: Deformation and hydrothermal alteration,” International Journal of Innovation and Applied Studies, vol. 42, no. 1, pp. 22–34, March 2024.
