| Revista: | Boletín de la Sociedad Geológica Mexicana |
| Base de datos: | PERIÓDICA |
| Número de sistema: | 000444867 |
| ISSN: | 1405-3322 |
| Autores: | Camprubí, Antoni1 Fuentes Guzmán, Edith1 Ortega Larrocea, Pilar1 Colín García, María1 Gabites, Janet2 Auqué, Luis F3 Colás, Vanessa1 González Partida, Eduardo4 |
| Instituciones: | 1Universidad Nacional Autónoma de México, Instituto de Geología, Ciudad de México. México 2University of British Columbia, Department of Earth, Ocean and Atmospheric Sciences, Vancouver, Columbia Británica. Canadá 3Universidad de Zaragoza, Departamento de Ciencias de la Tierra, Zaragoza. España 4Universidad Nacional Autónoma de México, Centro de Geociencias, Juriquilla, Querétaro. México |
| Año: | 2020 |
| Periodo: | Dic |
| Volumen: | 72 |
| Número: | 3 |
| País: | México |
| Idioma: | Inglés |
| Tipo de documento: | Artículo |
| Enfoque: | Analítico, descriptivo |
| Resumen en español | resumen está disponible en el texto completo |
| Resumen en inglés | The Ixtacamaxtitlán area in northern Puebla (central Mexico) contains middle Miocene Cu-Mo-Au porphyry/skarn and Pliocene low-sulfidation Au-Ag epithermal deposits that are geologically associated with the evolution of the Trans-Mexican Volcanic Belt (TMVB). In this paper, a new 40Ar/39Ar age (2.87 ± 0.41 Ma) is provided for rhombohedral alunite from a kaolinite + alunite ± opal ± cristobalite ± smectite advanced argillic alteration assemblage. This age contributes to the definition of a metallogenic province that is confined to the TMVB, a relevant feature for regional exploration. A ~12 My gap is established between the formation of the Cu-Mo-Au porphyry/skarn and low-sulfidation Au-Ag epithermal deposits, which rules out the possibility that their overlapping was the result of telescoping. Advanced argillic alteration is conspicuous throughout the mineralized area. This alteration assemblage consists of a widespread kaolinite-rich blanket that underlies silica sinters, polymictic hydrothermal breccias, and an alunite-rich spongy layer that consists of vertical tubular structures that are interpreted as the result of gas venting in a subaerial environment. The above indicate a shallow hypogene origin for the advanced argillic alteration assemblage-that is, formation by the partial condensation within a phreatic paleoaquifer of acidic vapors that were boiled-off along fractures that host epithermal veins at depth. The formation of the spongy alunite layer and silica sinters is interpreted to have been synchronous. Within the alunite-rich spongy layer, tubular structures hosted microbial consortia dominated by fungi and possible prokaryote (Bacteria or Archaea) biofilms. Such consortia were developed on previously formed alunite and kaolinite and were preserved due to their replacement by opal, kaolinite, or alunite. This means that the proliferation of fungi and prokaryotes occurred during a lull in acidic gas venting during which other organisms (i |
| Disciplinas: | Geociencias |
| Palabras clave: | Geología, México, Fechamiento, Alunita, Alteración argílica avanzada, Terrenos calentados por vapor, Hongos, Bacterias, Bioalteración, Biomineralización, Faja Volcánica Trans-Mexicana |
| Keyword: | Geology, Mexico, Dating, Alunite, Advanced argillic alteration, Steam-heated grounds, Fungi, Bacteria, Bioweathering, Biomineralization, Trans-Mexican Volcanic Belt |
| Texto completo: | Texto completo (Ver HTML) Texto completo (Ver PDF) |
