RT Journal Article
T1 Vein-type graphite in Jurassic volcanic rocks of the external zone of the Betic Cordillera, Southern Spain.
A1 Barrenechea, José F.
A1 Luque del Villar, Francisco Javier
A1 Rodas, Magdalena
A1 Pasteris, Jill D.
AB We have investigated volcanic-rock-hosted graphitem in eralization in the Huelma area of the Betic Cordillera, in southern Spain, in order to establish the mineralogical characteristics of the graphite andthe mechanism of its formation. The graphite is highlycrystalline, asrevealed by XRDandRaman spectroscopic data, andrelatively pure chemically (C content >90wt.%). XRD data demonstrate that some of themineralized bodies contain both hexagonal and rhombohedral graphite. Carbon isotopic compositions (-23.0< δ13 C <-20.7 ‰ ) and other geological observations indicate that thecarbon in the graphite was derived from organic matter included in the metamorphic basement. Cooling of a C-O-H fluid appears to be the most likely mechanism for precipitation of the graphite, although hydration reactions also may have played a role. The presence of rhombohedralgraphiteis discussed with reference to the kinetics of graphite formation.
PB Mineralogical Association of Canada
SN 0008-4476
YR 1997
FD 1997
LK https://hdl.handle.net/20.500.14352/58158
UL https://hdl.handle.net/20.500.14352/58158
LA eng
DS Docta Complutense
RD 2 may 2024