The Sabodala gold deposit in the Mako volcanic Belt (SE-Senegal, West African Craton) occurs in mafic and ultramafic rocks overlain by clastic sedimentary rocks and felsic volcanic-volcaniclastic sequences. It is a st...The Sabodala gold deposit in the Mako volcanic Belt (SE-Senegal, West African Craton) occurs in mafic and ultramafic rocks overlain by clastic sedimentary rocks and felsic volcanic-volcaniclastic sequences. It is a structurally controlled mesothermal vein gold deposit developed in deformed rocks units near the Falombo pluton. The Sabodala Goldfield comprises several faults systems striking N-S to NE-SW. New structural evolution consisting of both thrusting and transcurrent events has been defined for the Sabodala Goldfield. The majority of the gold at Sabodala occurs on the western flank of a large, doubling plunging dome (the Sabodala Antiform) and is also associated with sinistral wrenching that overprints early structures within the Sabodala Mine. The gold bearing veins are hosted by flat lying and NW-trending shear zones. The NW-trending faults acted as transfers syn-gold mineralization, although only discrete segments of these faults were active during the main stage of gold mineralization. Late exhumation resulted in extension along fault zones was responsible for the juxtaposition of medium and low grade metamorphic rocks. The granitic suite of the Falombo pluton is linked to exhumation. Final dextral transpression postdating exhumation produced shearing and folding. Gold lodes developed during brittle deformation are associated with high fluid pressures in a northwest-southeast shortening regime. These are termed mainly the Sabodala deposit, and secondary the Niakafiri and Masato deposits.展开更多
Geochemical and Geostatistical tools were used to assess: 1) the chemical quality and, geochemical processes in crystalline rock aquifers in Sabodala (Eastern Senegal) and its surroundings and 2) the impact of mining ...Geochemical and Geostatistical tools were used to assess: 1) the chemical quality and, geochemical processes in crystalline rock aquifers in Sabodala (Eastern Senegal) and its surroundings and 2) the impact of mining activities on their quality. A total of 26 water samples collected at boreholes, dug wells and stream, were analyzed to determine major and trace elements concentration focused on elements that represent more threats on human health. Boxplots define chemical characteristics of water for each aquifer formation compared to surface waters. Geostatistical analysis show two sources of water mineralization with regard to major elements: a first natural source characterized by Ca-Mg-HCO3 water type from boreholes and unpolluted surface water and a second group characterized by polluted water by nitrates with Na-NO3-Cl type mainly observed in upper weathered aquifers. However, considering trace element, geostatistical analysis showed three water groups: water with very low trace element concentrations encountered in boreholes and unpolluted surface waters, and waters with relatively high trace element concentrations such as Al observed in areas affected by gold mining activities and finally, polluted waters by Ni, Co, Mn and Cr observed at Sabodala. Results show that in eastern Senegal well waters are vulnerable and often affected by pollution.展开更多
The southeastern part of Senegal, in West Africa, is home to the country’s first major gold mine owned by Sabodala gold operations SGO, as subsidiary of Teranga Gold Corporation during the timeframe of this study. As...The southeastern part of Senegal, in West Africa, is home to the country’s first major gold mine owned by Sabodala gold operations SGO, as subsidiary of Teranga Gold Corporation during the timeframe of this study. As part of its expansion, the company opened and operated the Gora satellite mine for 4 years’ exploitation. At the end of the mine’s life, the authorities decided to close the site. In this context, SGO in compliance with its legal, regulatory and normative obligations, has commissioned a study of rehabilitation activities for a better environmental and social management of the Gora gold mine. This study is a first in Senegal and presents the general framework for the rehabilitation of a gold mine which will allow scientists to have several research perspectives in this field. The methodological approach consisted of a participatory process of collecting field data and data from stakeholders directly involved in mine rehabilitation and closure;these data were analyzed and coupled with international best practices in rehabilitation, closure, and post-mine management. Results of the selected options are based on known experiences from around the world, coupled with analysis of the SGO’s field activities results and those obtained from the synthesis of the interview guides from the numerous consultations. This synthesis made possible to align them with international guidelines presented in this document. In this context, the aspects related to the open-pit mine equipment, processing facilities and related infrastructure were a particular interest to the various stakeholders. Thus, the following rehabilitation options were retained by the group constituted by the populations: 1) Backfilling pits, for cultivation practices and development of agribusiness and the establishment of grazing land for livestock;2) Setting up water storage basins for the sustainable development of certain activities around the mine and aquifer recharge while respecting the protection and safety standards of the basin in order to avoid the risks of accidents;3) Returning certain facilities to the communities and the competent State services. These few measures will allow the indigenous populations affected by the mine to participate in the rehabilitation program by integrating all relevant ideas and discussions on the issues of rehabilitation as perceived by the actors involved in the study, as well as the implementation of the best international strategic orientations in this field for sustainable development. In addition, it will be necessary to set up an internal technical committee within the mining company to coordinate the rehabilitation and closure operations with the various departments, and an external technical committee composed of the relevant government departments, the local community, and civil society, among others, to examine and validate the closure options. A closure clearance should be issued to operators who have responsibly closed their mines.展开更多
文摘The Sabodala gold deposit in the Mako volcanic Belt (SE-Senegal, West African Craton) occurs in mafic and ultramafic rocks overlain by clastic sedimentary rocks and felsic volcanic-volcaniclastic sequences. It is a structurally controlled mesothermal vein gold deposit developed in deformed rocks units near the Falombo pluton. The Sabodala Goldfield comprises several faults systems striking N-S to NE-SW. New structural evolution consisting of both thrusting and transcurrent events has been defined for the Sabodala Goldfield. The majority of the gold at Sabodala occurs on the western flank of a large, doubling plunging dome (the Sabodala Antiform) and is also associated with sinistral wrenching that overprints early structures within the Sabodala Mine. The gold bearing veins are hosted by flat lying and NW-trending shear zones. The NW-trending faults acted as transfers syn-gold mineralization, although only discrete segments of these faults were active during the main stage of gold mineralization. Late exhumation resulted in extension along fault zones was responsible for the juxtaposition of medium and low grade metamorphic rocks. The granitic suite of the Falombo pluton is linked to exhumation. Final dextral transpression postdating exhumation produced shearing and folding. Gold lodes developed during brittle deformation are associated with high fluid pressures in a northwest-southeast shortening regime. These are termed mainly the Sabodala deposit, and secondary the Niakafiri and Masato deposits.
文摘Geochemical and Geostatistical tools were used to assess: 1) the chemical quality and, geochemical processes in crystalline rock aquifers in Sabodala (Eastern Senegal) and its surroundings and 2) the impact of mining activities on their quality. A total of 26 water samples collected at boreholes, dug wells and stream, were analyzed to determine major and trace elements concentration focused on elements that represent more threats on human health. Boxplots define chemical characteristics of water for each aquifer formation compared to surface waters. Geostatistical analysis show two sources of water mineralization with regard to major elements: a first natural source characterized by Ca-Mg-HCO3 water type from boreholes and unpolluted surface water and a second group characterized by polluted water by nitrates with Na-NO3-Cl type mainly observed in upper weathered aquifers. However, considering trace element, geostatistical analysis showed three water groups: water with very low trace element concentrations encountered in boreholes and unpolluted surface waters, and waters with relatively high trace element concentrations such as Al observed in areas affected by gold mining activities and finally, polluted waters by Ni, Co, Mn and Cr observed at Sabodala. Results show that in eastern Senegal well waters are vulnerable and often affected by pollution.
文摘The southeastern part of Senegal, in West Africa, is home to the country’s first major gold mine owned by Sabodala gold operations SGO, as subsidiary of Teranga Gold Corporation during the timeframe of this study. As part of its expansion, the company opened and operated the Gora satellite mine for 4 years’ exploitation. At the end of the mine’s life, the authorities decided to close the site. In this context, SGO in compliance with its legal, regulatory and normative obligations, has commissioned a study of rehabilitation activities for a better environmental and social management of the Gora gold mine. This study is a first in Senegal and presents the general framework for the rehabilitation of a gold mine which will allow scientists to have several research perspectives in this field. The methodological approach consisted of a participatory process of collecting field data and data from stakeholders directly involved in mine rehabilitation and closure;these data were analyzed and coupled with international best practices in rehabilitation, closure, and post-mine management. Results of the selected options are based on known experiences from around the world, coupled with analysis of the SGO’s field activities results and those obtained from the synthesis of the interview guides from the numerous consultations. This synthesis made possible to align them with international guidelines presented in this document. In this context, the aspects related to the open-pit mine equipment, processing facilities and related infrastructure were a particular interest to the various stakeholders. Thus, the following rehabilitation options were retained by the group constituted by the populations: 1) Backfilling pits, for cultivation practices and development of agribusiness and the establishment of grazing land for livestock;2) Setting up water storage basins for the sustainable development of certain activities around the mine and aquifer recharge while respecting the protection and safety standards of the basin in order to avoid the risks of accidents;3) Returning certain facilities to the communities and the competent State services. These few measures will allow the indigenous populations affected by the mine to participate in the rehabilitation program by integrating all relevant ideas and discussions on the issues of rehabilitation as perceived by the actors involved in the study, as well as the implementation of the best international strategic orientations in this field for sustainable development. In addition, it will be necessary to set up an internal technical committee within the mining company to coordinate the rehabilitation and closure operations with the various departments, and an external technical committee composed of the relevant government departments, the local community, and civil society, among others, to examine and validate the closure options. A closure clearance should be issued to operators who have responsibly closed their mines.
