Bella Rica is sited in the Ponce Enriquez mining district (south of Ecuador), one of the most important gold mining areas in Ecuador, active since 1980’s. Gold mesothermal mineralization is hosted within Cretaceous mafic volcanic rocks of Pallatanga Units (Pratt et al., 2005). The high level of heavy metal(loid)s concentration (As, Cu, Cd, Zn, and Pb) in stream sediments and other matrixes (surface water, soil, and biological) has been discussed in several studies (e.g., Williams et al., 2000; Jiménez-Oyola et al., 2021). The presence of heavy metal(loid)s in the mining district has been considered as due to the superposition of geogenic sources and mining activity. Gold is recovered by leaching with cyanide and flotation in artisanal activity and by a combination of amalgamation with mercury in the illegal mining activity. Despite aforementioned environmental investigations, the studies on the characterization and origin of the Au mineralization are still limited. With the aim of contributing to the regional geological background, in this study, we present new data on the geochemical and petrographic features of the hydrothermal gold mineralization in the Ponce Enriquez area. Detailed maps of the distribution of selected heavy metal(loid)s are provided. Furthermore, petrologic investigations are carried out with the aim to characterize temperatures and composition of hydrothermal fluids involved in the genesis of Ponce Enriquez ore deposit. These data can help to increase the regional geological knowledge and the promotion of the sustainable development of Ecuador metalliferous mineral sector. Jimenez-Oyola S., Garcia-Martinez M.-J., Ortega M.F., Chavez E., Garcia-Garizabal I. & Bolonio D. (2021) - Ecological and probabilistic human health risk assessment of heavy metal(loid)s in river sediments affected by mining activities in Ecuador. Environ. Geochem. Health, 43, 4459-4474. Pratt W.T., Duque P. & Ponce M. (2005) - An autochthonous geological model for the eastern Andes of Ecuador. Tectonophysics, 399, 251-278. Williams T.M., Dunkley P.N., Cruz E., Actimbay V., Gaibor A., Lopez E., Baez N. & Aspden J.A. (2000) - Regional geochemical reconnaissance of the Cordillera Occidental of Ecuador: economic and environmental applications. Appl. Geochem., 15, 531-550.
Geochemical and petrographic characterization of the Bella Rica hydrothermal gold mineralization (Ponce Enriquez, Ecuador)
Fornasaro S.;Fulignati P.;Gioncada A.
;
2022-01-01
Abstract
Bella Rica is sited in the Ponce Enriquez mining district (south of Ecuador), one of the most important gold mining areas in Ecuador, active since 1980’s. Gold mesothermal mineralization is hosted within Cretaceous mafic volcanic rocks of Pallatanga Units (Pratt et al., 2005). The high level of heavy metal(loid)s concentration (As, Cu, Cd, Zn, and Pb) in stream sediments and other matrixes (surface water, soil, and biological) has been discussed in several studies (e.g., Williams et al., 2000; Jiménez-Oyola et al., 2021). The presence of heavy metal(loid)s in the mining district has been considered as due to the superposition of geogenic sources and mining activity. Gold is recovered by leaching with cyanide and flotation in artisanal activity and by a combination of amalgamation with mercury in the illegal mining activity. Despite aforementioned environmental investigations, the studies on the characterization and origin of the Au mineralization are still limited. With the aim of contributing to the regional geological background, in this study, we present new data on the geochemical and petrographic features of the hydrothermal gold mineralization in the Ponce Enriquez area. Detailed maps of the distribution of selected heavy metal(loid)s are provided. Furthermore, petrologic investigations are carried out with the aim to characterize temperatures and composition of hydrothermal fluids involved in the genesis of Ponce Enriquez ore deposit. These data can help to increase the regional geological knowledge and the promotion of the sustainable development of Ecuador metalliferous mineral sector. Jimenez-Oyola S., Garcia-Martinez M.-J., Ortega M.F., Chavez E., Garcia-Garizabal I. & Bolonio D. (2021) - Ecological and probabilistic human health risk assessment of heavy metal(loid)s in river sediments affected by mining activities in Ecuador. Environ. Geochem. Health, 43, 4459-4474. Pratt W.T., Duque P. & Ponce M. (2005) - An autochthonous geological model for the eastern Andes of Ecuador. Tectonophysics, 399, 251-278. Williams T.M., Dunkley P.N., Cruz E., Actimbay V., Gaibor A., Lopez E., Baez N. & Aspden J.A. (2000) - Regional geochemical reconnaissance of the Cordillera Occidental of Ecuador: economic and environmental applications. Appl. Geochem., 15, 531-550.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
