RT Journal Article
T1 Hydrothermal palladium enrichment in podiform chromitites of Calzadilla de los Barros (SW Iberian Peninsula)
A1 Merinero Palomares, Raúl
A1 Lunar Hernández, Rosario
A1 Ortega Menor, Lorena
A1 Piña García, Rubén
A1 Monterrubio Pérez, Serafín
A1 Gervilla, Fernando
AB The serpentinized peridotite massifs of Calzadilla de los Barros (Ossa-Morena zone, Iberian massif) consist of harzburgites and small dunite bodies containing Al-rich chromitite pods. Minor discordant clinopyroxenite veins cut the peridotite massifs. The chromitites show total transformation of the silicate matrix into chlorite and post-magmatic formation of chalcopyrite, millerite, magnetite, and chalcedony. Olivine in harzburgites and dunites is mainly transformed into pargasite. The clinopyroxenites show diopside transformation into epidote, grossular, and titanite and locally into hydrous minerals (chlorite, pargasite, and tremolite) associated with the formation of Cu-Fe-Ni sulfides, suggesting significant hydrothermal alteration. The chondrite-normalized platinum-group elements patterns of the chromitites are very similar to those of the harzburgites and clinopyroxenites, showing an unusual sharply positive slope from Pt to Pd, as well as high Pd/Ir ratios. In the chromitites, the Pd/Ir ratio shows both positive and negative linear correlations with bulk platinum-group element contents. These results suggest that most of the Os, Ir, and Ru were incorporated during the magmatic phase, while Pd and Pt were incorporated during post-magmatic processes of hydrothermal alteration and formation of Cu-Fe-Ni sulfides. This study provides a better understanding of the post-magmatic processes that allow Pd enrichment in ophiolite complexes, and highlights how platinum-group element patterns can provide significant insights into both magmatic and post-magmatic processes.
PB Mineralogical Association of Canada
SN 0008-4476
YR 2013
FD 2013-06-01
LK https://hdl.handle.net/20.500.14352/34444
UL https://hdl.handle.net/20.500.14352/34444
LA eng
NO Ministerio de Ciencia e Innovación(MICINN)
DS Docta Complutense
RD 30 abr 2024