ABSTRACT:Gold and copper deposits in Central America are hosted by island arc volcanic rocks of Late Cretaceous and younger age. Low potassium tholeiitic basalts form the base of the volcanic pile and were deposited in an intraoceanic island arc. Volcanism became more potassic with time, and by Late Miocene time, calcalkaline andesites dominate the volcanic rock record. Alkaline volcanic rocks appeared about five million years ago but are underreported in older portions of the arc. Porphyry copper deposits are centered on calc-alkaline plutons of intermediate (quartz diorite to quartz monzonite) composition and are typically anomalous in gold. Although some of the porphyry deposits contain in excess of a billion tonnes, none are in production. Bonanza gold veins cluster around sub-volcanic intrusions in districts which mimic the spacing of active volcanoes. Precious metal bonanzas, a number of which produced in excess of a billion ounces of gold, are responsible for the bulk of historic gold production in Central America. Hot spring gold deposits are being discovered along a regional unconformity which marks the emergence of the present-day island arc from the ocean. Although discovered only recently, some of these deposits already exceed a million ounces. Host rocks include exogenous domes and surrounding pyroclastic aprons. Exploration efforts today focus on bulk-mineable deposits: porphyry-related stockworks, skarns, and epithermal stockworks and disseminated deposits. Regional strike-slip faults parallel to the Nicaraguan depression control the distribution of both gold and copper throughout Central America. Age dates provide documentation for mineralization throughout the history of the arc, a period of close to 100 million years. RESUMEN:Los depósitos de oro y cobre en América Central se encuentran dentro de rocas del Cretácico Tardío y más jóvenes del arco insular volcánico. Basaltos toleíticos bajos en potasio forman la base de la agrupación volcánica y fueron depositados en un arco insular intraoceánico. El vulcanismo se tornó mas potásico con el tiempo, y ya para el Mioceno tardío, las andesitas calco-alcalinas dominan la secuencia volcánica. Rocas volcánicas alcalinas aparecieron hace unos cinco millones de años pero han sido sub-reportadas en areas más antiguas del arco. Depósitos porfídicos de cobre se centran sobre plutones calco-alcalinos de composición intermedia, diorita cuarcífera a diorita monzonítica y que típicamente son anómalas en oro. Aunque algunos de los depósitos porfídi-cos contienen más del billón de toneladas, ninguno está en producción. Vetas auríferas tipo bonanza se agrupan alrededor de intrusiones subvolcánicas en distritos que asemejan la distribución espacial de volcanes activos. Bonanzas de metales preciosos, algunos de los cuales produjeron por encima del millón de onzas de oro, son responsables por la mayor parte de la producción histórica en América Central. Se han venido descubriendo depósitos auríferos a lo largo de una inconformidad regional que marca el nacimiento del ...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.