Deposition of highly crystalline graphite from moderate-temperature fluids
Luque, F.J.; Ortega, Lorena; Barrenechea, Jose Fernandez; Millward, David; Beyssac, Olivier; Huizenga, Jan Marten. 2009 Deposition of highly crystalline graphite from moderate-temperature fluids. Geology, 37 (3). 275-278. 10.1130/G25284A.1Full text not available from this repository. (Request a copy)
Recognized large occurrences of fluid-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 X CO2/(XCO2 + X CH4) ratio of 0.69, thus indicating temperatures of ~500 °C at the fayalite-magnetite-quartz buffered conditions. Therefore, this is the first reported evidence indicating that huge concentrations of highly crystalline graphite can precipitate from moderate-temperature fluids.
|Programmes:||BGS Programmes 2008 > Geology and Landscape England|
|Additional Keywords:||Graphite deposits|
|NORA Subject Terms:||Earth Sciences|
|Date made live:||12 Mar 2009 11:49|
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