Prossima pubblicazione.
Referenza:
▪ González-Pérez, I., Gervilla, F., González-Jiménez, J.M., Kojonen, K. (2021): Genesis of an exotic platinum-group-mineral-rich and Mg-poor chromitite in the Kevitsa Ni-Cu-platinum-group-elements deposit. Mineralogy and Petrology, 115, (in press).
Abstract:
This paper offers the first-ever study of a local chromitite stringer (~ 2 cm wide) enriched in platinum-group elements (PGE) from the Kevitsa Ni-Cu-PGE deposit. Chromite forming this chromitite is rich in Cr2O3 (29.06 ̶ 37.17 wt%) and FeO (FeOtotal = 45.88 ̶ 56.06 wt%) and low in MgO (0.04 ̶ 0.91 wt%). The chromitite host an unusual set of mineral inclusions including: (1) platinum-group minerals of the laurite-erlichmanite (RuS2-OsS2) solid solution series, irarsite (IrAsS), sperrylite (PtAs2), hollingworthite (RhAsS), anduoite [(Ru, Os)As2], kotulskite (PdTe) and As-, Te-, Os-, and Ru- bearing unidentified phases; (2) exsolution-lamellae of ilmenite and ulvöspinel along with chromite (111) and (100) planes, respectively; (3) silicates including crystallographically-oriented biotite, euhedral pyroxene and irregular-shaped amphiboles which tend to follow chromite growth planes, and (4) Fe-oxides, pyrrhotite, pentlandite, galena, barite, apatite, and native gold. Intercumulus minerals are microcrystalline Mg-rich biotite and minor amphibole. Pyroxenes (diopside) located immediately above the chromitite stringer exhibit higher CaO (23.02 ̶ 25.42 wt%) and Na2O (0.16 ̶ 0.55 wt%) than pyroxenes (augite) located below. We suggest that chromite saturation in the mafic melt was caused by local assimilation of a small pelitic xenolith. The xenolith also provided K and H2O explaining the occurrence of K-and volatile-rich intercumulus phases. Crystallization of chromite in this environment promoted preferential sequestering of Ir and Ru, and to a lesser extent Os, from the parental magma giving rise to an anomalous iridium-group-PGE (IPGE: Ir, Ru, and Os) enrichment.
An exotic platinum-group-mineral-rich and Mg-poor chromitite in the Kevitsa Ni-Cu-platinum-group-elements deposit
- Marco E. Ciriotti
- Messaggi: 31675
- Iscritto il: ven 25 giu, 2004 11:31
- Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
- Contatta:
An exotic platinum-group-mineral-rich and Mg-poor chromitite in the Kevitsa Ni-Cu-platinum-group-elements deposit
Marco E. Ciriotti
«Things are interesting only in so far as they relate themselves to other things»
«Things are interesting only in so far as they relate themselves to other things»
- Marco E. Ciriotti
- Messaggi: 31675
- Iscritto il: ven 25 giu, 2004 11:31
- Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
- Contatta:
Re: An exotic platinum-group-mineral-rich and Mg-poor chromitite in the Kevitsa Ni-Cu-platinum-group-elements deposit
Pubblicazione effettuata.
Referenza:
▪ González-Pérez, I., Gervilla, F., González-Jiménez, J.M., Kojonen, K. (2021): Genesis of an exotic platinum-group-mineral-rich and Mg-poor chromitite in the Kevitsa Ni-Cu-platinum-group-elements deposit. Mineralogy and Petrology, 115, 535–555.
Referenza:
▪ González-Pérez, I., Gervilla, F., González-Jiménez, J.M., Kojonen, K. (2021): Genesis of an exotic platinum-group-mineral-rich and Mg-poor chromitite in the Kevitsa Ni-Cu-platinum-group-elements deposit. Mineralogy and Petrology, 115, 535–555.
Marco E. Ciriotti
«Things are interesting only in so far as they relate themselves to other things»
«Things are interesting only in so far as they relate themselves to other things»
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