Deposition of highly crystalline graphite from moderate-temperature fluids
Recognized large occurrences of fl uid-deposited graphite displaying high crystallinity were previously restricted to high-temperature environments (mainly granulite facies terranes). However, in the extensively mined Borrowdale deposit (UK), the mineralogical assemblage, notably the graphite-epidot...
| Autores: | , , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2009 |
| País: | España |
| Institución: | Universidad Complutense de Madrid (UCM) |
| Repositorio: | Docta Complutense |
| Idioma: | inglés |
| OAI Identifier: | oai:docta.ucm.es:20.500.14352/52119 |
| Acceso en línea: | https://hdl.handle.net/20.500.14352/52119 |
| Access Level: | acceso abierto |
| Palabra clave: | 553.91 Graphite deposition Geología 2506 Geología |
| Sumario: | Recognized large occurrences of fl uid-deposited graphite displaying high crystallinity were previously restricted to high-temperature environments (mainly granulite facies terranes). However, in the extensively mined Borrowdale deposit (UK), the mineralogical assemblage, notably the graphite-epidote intergrowths, shows that fully ordered graphite precipitated during the propylitic hydrothermal alteration of the volcanic host rocks. Fluids responsible for graphite deposition had an average XCO2/(XCO2 + XCH4) ratio of 0.69, thus indicating temperatures of ~500 °C at the fayalite-magnetite-quartz buffered conditions. Therefore, this is the fi rst reported evidence indicating that huge concentrations of highly crystalline graphite can precipitate from moderate-temperature fluids. |
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