Geochronology of Mexican mineral deposits. VII: the Peña Colorada magmatic-hydrothermal iron oxide deposits (IOCG “clan”), Colima
The Peña Colorada mineralized area contains several iron oxide-apatite (IOA) deposits around the arguably richest known iron resource in Mexico. The Lower Cretaceous volcano-sedimentary host rock sequence has been subjected to several episodes of hydrothermal alteration, each accompanied by a distin...
| Autores: | , , , , , , , , |
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| Tipo de documento: | artigo |
| Estado: | Versão publicada |
| Data de publicação: | 2018 |
| País: | México |
| Recursos: | Universidad Nacional Autónoma de México |
| Repositório: | Redalyc-UNAM |
| OAI Identifier: | oai:redalyc.org:94358881004 |
| Acesso em linha: | https://www.redalyc.org/articulo.oa?id=94358881004 https://www.redalyc.org/journal/943/94358881004/ https://www.redalyc.org/journal/943/94358881004/html/ https://www.redalyc.org/journal/943/94358881004/94358881004.epub https://www.redalyc.org/journal/943/94358881004/movil |
| Access Level: | Acceso aberto |
| Palavra-chave: | Ciencias de la Tierra IOA 40Ar magmatic magnetite Iron oxide |
| Resumo: | The Peña Colorada mineralized area contains several iron oxide-apatite (IOA) deposits around the arguably richest known iron resource in Mexico. The Lower Cretaceous volcano-sedimentary host rock sequence has been subjected to several episodes of hydrothermal alteration, each accompanied by a distinct episode of faulting and intrusion (calc-alkaline to tholeiitic). Faulting is partly associated with the reactivation of cryptic structural corridors in basement rocks. High-resolution 40Ar/39Ar and apatite fission track (AFT) dating of this deposit and the adjacent Arrayanes prospect reveal the following sequence of events that range from the latest Cretaceous to the earliest Eocene: (1) intrusion of a 67.6 ± 3.5 Ma magnetite-bearing diorite with associated skarn/skarnoid metamorphism that was coeval or predated N–S to NNW–SSE faulting; (2) approximately 63.26 Ma syenite-like potassic alteration with disseminated magnetite, predated by N–S to NNW–SSE faulting and postdated by WNW–ESE faulting; (3) intrusion of 62.0 ± 2.5 Ma diorite and 59.39 ± 0.21 Ma andesite dikes that predate the main mineralization event at 55.72 to 54.84 Ma of large semi-stratabound massive and disseminated bodies; (4) intrusion of a 53.3 ± 3.0 Ma magnetite-bearing gabbro and 53 ± 2 Ma pegmatoid magnetite + fluorapatite veins at the Arrayanes prospect, which overlap the WNW–ESE faulting; (5) 50.70 to 48.18 Ma polymictic magnetite breccia as the last stage of mineralization in the area, predated by E–W faulting; and (6) reactivation of WNW–ESE faults and later NE–SW faults. Therefore, the total age span of the Peña Colorada deposit ranges between approximately 19 and 23 million years. The closeness in age between intrusions and mineralization in the Arrayanes prospect, their confinement between the WNW–ESE and E–W structural domains, and mingling or mixing structures between gabbro and diorite with an associated magmatic magnetite enrichmentsupport the idea of a close genetic link between such intrusives andIOA hydrothermal mineralization... |
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