Platinum-Group Minerals of the River Ko Watershed, Sisim Placer Zone, Eastern Sayans, Russia

database, nuove specie, discrediti,
ridefinizioni, classificazioni, ecc.
Rispondi
Avatar utente
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:

Platinum-Group Minerals of the River Ko Watershed, Sisim Placer Zone, Eastern Sayans, Russia

Messaggio da Marco E. Ciriotti » lun 03 ott, 2022 16:09

Prossima pubblicazione.

Referenza:
▪ Barkov, A.Y., Tolstykh, N.D., Nikiforov, A.A., Martin, R.F. (2023): The Platinum-Group Minerals of the River Ko Watershed, Sisim Placer Zone, Eastern Sayans, Russia, and the diffrentiation of multicomponent melts. The Canadian Journal of Mineralogy and Petrology, 61, (in press).
Marco E. Ciriotti

«Things are interesting only in so far as they relate themselves to other things»

Avatar utente
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: Platinum-Group Minerals of the River Ko Watershed, Sisim Placer Zone, Eastern Sayans, Russia

Messaggio da Marco E. Ciriotti » lun 31 lug, 2023 17:35

Pubblicazione effettuata.

Referenza:
▪ Barkov, A.Y., Tolstykh, N.D., Nikiforov, A.A., Martin, R.F. (2023): The Platinum-Group Minerals of the River Ko Watershed, Sisim Placer Zone, Eastern Sayans, Russia, and the diffrentiation of multicomponent melts. The Canadian Journal of Mineralogy and Petrology, 61, 805-824.

Abstract:
The textures and chemical compositions (based on the results of over 1000 analyses) of a suite of platinum-group minerals obtained from concentrates collected along the River Ko watershed in the Sisim placer zone, Eastern Sayans, Russia, have been analyzed and described. Detrital grains of Ir–Os alloy, considered to have been derived from the Lysanskiy layered ultrabasic complex, are interpreted to be domains of melt in the interstices of olivine–chromian spinel cumulates. This melt fractionated before crystallization of the alloys; some domains show a core-to-rim enrichment in Ir. The incompatible behavior of lithophile elements, base metals, S, semimetals, and H2O in the melt now represented by the alloy led to the crystallization of a broad range of ore minerals in multicomponent globules of residual melt. In this way, laurite and cuproiridsite developed in the melt and now are in a symplectitic intergrowth with the alloy. A spherule of laurite with a core of anthophyllite-rich amphibole and a mantle of irarsite shows that H2O and lithophile components were also present in the PGE-rich melt. Rhodium-rich pentlandite-related minerals, likely including oberthürite, postdate the crystallization of laurite; these may be Ru-enriched and may contain lamellar grains of torryweiserite or ferrotorryweiserite, both of which may represent exsolution products. These two species, and the related kuvaevite, which locally replace the Rh-rich pentlandite-related minerals, appear to be paragenetically later. The new data provide valuable insight on the evolution of late, multicomponent melts in basic–ultrabasic complexes.
Marco E. Ciriotti

«Things are interesting only in so far as they relate themselves to other things»

Rispondi

Chi c’è in linea

Visitano il forum: Bing [Bot] e 52 ospiti