The record in spinel peridotite xenoliths in Mt. Pinatubo, Philippines

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:

The record in spinel peridotite xenoliths in Mt. Pinatubo, Philippines

Messaggio da Marco E. Ciriotti » ven 09 nov, 2018 14:47

Referenza:
▪ Payot, B.D., Arai, S., Yoshikawa, M., Tamura, A., Okuno, M., Rivera, D.J.V. (2018): Mantle Evolution from Ocean to Arc: The Record in Spinel Peridotite Xenoliths in Mt. Pinatubo, Philippines. Minerals, 8, 515; https://doi.org/10.3390/min8110515

Abstract:
A suite of peridotite xenoliths were collected from lahar flow deposits located close to the summit of Mt. Pinatubo. Spinel harzburgite is the most dominant lithology among dunites, pyroxenites and websterites. A rare spinel lherzolite xenolith (P12-7) is also present in this suite. The spinel lherzolite has well-preserved protogranular texture with very minimal presence of secondary amphibole, low Cr# in the chromian spinel, and depleted and hump shaped patterns of chondrite-normalized rare earth element (REE) patterns for the clinopyroxenes. In contrast, the spinel harzburgites contain abundant secondary amphiboles and orthopyroxenes, higher Cr# in the spinel, and slightly elevated patterns for the chondrite-normalized REE patterns for the amphiboles. The spinel lherzolite also exhibits higher olivine Fo content for a given spinel Cr# compared to the spinel harzburgites. The spinel lherzolite is interpreted as a typical residue from partial melting of abyssal peridotites whereas the spinel harzburgites may have formed via partial melting with subsequent modification during the influx of fluids in the mantle wedge. Our results suggest that fragments of MOR-derived lithosphere exist in the mantle wedge beneath the Philippine island arc. This work provides evidence for the conversion of abyssal to arc peridotites in the mantle wedge.
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: Google [Bot] e 48 ospiti