Trace-metal content of the Cerro Quema Au-Cu deposit (Azuero Peninsula, Panama): Implications for exploration
Abstract Cerro Quema (Azuero Peninsula, Panama) is a high-sulfidation epithermal Au-Cu deposit hosted by a dacite dome complex of the Río Quema Formation (late Campanian to Maastrichtian). High-sulfidation mineralization at Cerro Quema occurs within a lithocap of vuggy quartz and advanced argillic alteration, and comprises a first stage of disseminations and microveinlets of pyrite, chalcopyrite, enargite, tennantite, and minor sphalerite. This stage is crosscut by younger veins that contain quartz, barite, pyrite, chalcopyrite, sphalerite, and galena. Later weathering and oxidation processes have produced two distinct mineralized zones at Cerro Quema: (1) Sulfide ore zone-a deeper zone of hypogene alteration and sulfide mineralization with some secondary enrichment but unaffected by oxidation, and (2) Oxide ore zone-a thick iron oxide-rich zone that overprints the hypogene alteration/ mineralization in the upper ~150 m of the deposit. To characterize the concentrations and distribution of metals in the two ore zones, and to develop geochemical tools for exploration, we analyzed 34 samples of both oxide (n = 23) and sulfide ore (n = 11) for Au, Ag, Cd, Cu, Mn, Mo, Ni, Pb, Zn, S, As, Ba, Hg, Sb, and W by INAA and ICP-MS. The results show that the oxide ore has the highest concentration of Au (2.4 g/t), Ag (2.0 g/t), Pb (432 ppm), and Sb (317 ppm), whereas the sulfide ore has the highest concentration of Cu (> 1%), Zn (403 ppm), As (2.74%), and Cd (15.2 ppm). The enrichment factor calculation (oxide/ sulfide ore) indicate that Au, Ag, Pb, and Sb are concentrated in the oxide zone whereas Cu, Zn, Ba, Ni, As, and S are concentrated in the sulfide zone. Exploration for Au should target the oxide ore zone, in areas where the Ba concentration is also high. Exploration for Cu should target the sulfide ore zone, below the oxidation boundary, where primary and secondary Cu sulfides coexist.
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Sociedad Geológica Mexicana A.C.
2018
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oai:scielo:S1405-332220180002005492018-11-08Trace-metal content of the Cerro Quema Au-Cu deposit (Azuero Peninsula, Panama): Implications for explorationCorral,IsaacCorbella,MercèGómez-Gras,DavidGriera,Albert Exploration Epithermal Cerro Quema Gold-Copper Panama Abstract Cerro Quema (Azuero Peninsula, Panama) is a high-sulfidation epithermal Au-Cu deposit hosted by a dacite dome complex of the Río Quema Formation (late Campanian to Maastrichtian). High-sulfidation mineralization at Cerro Quema occurs within a lithocap of vuggy quartz and advanced argillic alteration, and comprises a first stage of disseminations and microveinlets of pyrite, chalcopyrite, enargite, tennantite, and minor sphalerite. This stage is crosscut by younger veins that contain quartz, barite, pyrite, chalcopyrite, sphalerite, and galena. Later weathering and oxidation processes have produced two distinct mineralized zones at Cerro Quema: (1) Sulfide ore zone-a deeper zone of hypogene alteration and sulfide mineralization with some secondary enrichment but unaffected by oxidation, and (2) Oxide ore zone-a thick iron oxide-rich zone that overprints the hypogene alteration/ mineralization in the upper ~150 m of the deposit. To characterize the concentrations and distribution of metals in the two ore zones, and to develop geochemical tools for exploration, we analyzed 34 samples of both oxide (n = 23) and sulfide ore (n = 11) for Au, Ag, Cd, Cu, Mn, Mo, Ni, Pb, Zn, S, As, Ba, Hg, Sb, and W by INAA and ICP-MS. The results show that the oxide ore has the highest concentration of Au (2.4 g/t), Ag (2.0 g/t), Pb (432 ppm), and Sb (317 ppm), whereas the sulfide ore has the highest concentration of Cu (> 1%), Zn (403 ppm), As (2.74%), and Cd (15.2 ppm). The enrichment factor calculation (oxide/ sulfide ore) indicate that Au, Ag, Pb, and Sb are concentrated in the oxide zone whereas Cu, Zn, Ba, Ni, As, and S are concentrated in the sulfide zone. Exploration for Au should target the oxide ore zone, in areas where the Ba concentration is also high. Exploration for Cu should target the sulfide ore zone, below the oxidation boundary, where primary and secondary Cu sulfides coexist.info:eu-repo/semantics/openAccessSociedad Geológica Mexicana A.C.Boletín de la Sociedad Geológica Mexicana v.70 n.2 20182018-01-01info:eu-repo/semantics/articletext/htmlhttp://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1405-33222018000200549en10.18268/bsgm2018v70n2a14 |
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México |
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MX |
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revista |
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America del Norte |
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English |
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| author |
Corral,Isaac Corbella,Mercè Gómez-Gras,David Griera,Albert |
| spellingShingle |
Corral,Isaac Corbella,Mercè Gómez-Gras,David Griera,Albert Trace-metal content of the Cerro Quema Au-Cu deposit (Azuero Peninsula, Panama): Implications for exploration |
| author_facet |
Corral,Isaac Corbella,Mercè Gómez-Gras,David Griera,Albert |
| author_sort |
Corral,Isaac |
| title |
Trace-metal content of the Cerro Quema Au-Cu deposit (Azuero Peninsula, Panama): Implications for exploration |
| title_short |
Trace-metal content of the Cerro Quema Au-Cu deposit (Azuero Peninsula, Panama): Implications for exploration |
| title_full |
Trace-metal content of the Cerro Quema Au-Cu deposit (Azuero Peninsula, Panama): Implications for exploration |
| title_fullStr |
Trace-metal content of the Cerro Quema Au-Cu deposit (Azuero Peninsula, Panama): Implications for exploration |
| title_full_unstemmed |
Trace-metal content of the Cerro Quema Au-Cu deposit (Azuero Peninsula, Panama): Implications for exploration |
| title_sort |
trace-metal content of the cerro quema au-cu deposit (azuero peninsula, panama): implications for exploration |
| description |
Abstract Cerro Quema (Azuero Peninsula, Panama) is a high-sulfidation epithermal Au-Cu deposit hosted by a dacite dome complex of the Río Quema Formation (late Campanian to Maastrichtian). High-sulfidation mineralization at Cerro Quema occurs within a lithocap of vuggy quartz and advanced argillic alteration, and comprises a first stage of disseminations and microveinlets of pyrite, chalcopyrite, enargite, tennantite, and minor sphalerite. This stage is crosscut by younger veins that contain quartz, barite, pyrite, chalcopyrite, sphalerite, and galena. Later weathering and oxidation processes have produced two distinct mineralized zones at Cerro Quema: (1) Sulfide ore zone-a deeper zone of hypogene alteration and sulfide mineralization with some secondary enrichment but unaffected by oxidation, and (2) Oxide ore zone-a thick iron oxide-rich zone that overprints the hypogene alteration/ mineralization in the upper ~150 m of the deposit. To characterize the concentrations and distribution of metals in the two ore zones, and to develop geochemical tools for exploration, we analyzed 34 samples of both oxide (n = 23) and sulfide ore (n = 11) for Au, Ag, Cd, Cu, Mn, Mo, Ni, Pb, Zn, S, As, Ba, Hg, Sb, and W by INAA and ICP-MS. The results show that the oxide ore has the highest concentration of Au (2.4 g/t), Ag (2.0 g/t), Pb (432 ppm), and Sb (317 ppm), whereas the sulfide ore has the highest concentration of Cu (> 1%), Zn (403 ppm), As (2.74%), and Cd (15.2 ppm). The enrichment factor calculation (oxide/ sulfide ore) indicate that Au, Ag, Pb, and Sb are concentrated in the oxide zone whereas Cu, Zn, Ba, Ni, As, and S are concentrated in the sulfide zone. Exploration for Au should target the oxide ore zone, in areas where the Ba concentration is also high. Exploration for Cu should target the sulfide ore zone, below the oxidation boundary, where primary and secondary Cu sulfides coexist. |
| publisher |
Sociedad Geológica Mexicana A.C. |
| publishDate |
2018 |
| url |
http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1405-33222018000200549 |
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