Incorporation of high amounts of Na in ringwoodite: Possible implications for transport of alkali into lower mantle

database, nuove specie, discrediti,
ridefinizioni, classificazioni, ecc.
Rispondi
Avatar utente
Marco E. Ciriotti
Messaggi: 24004
Iscritto il: ven 25 giu, 2004 11:31
Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
Contatta:

Incorporation of high amounts of Na in ringwoodite: Possible implications for transport of alkali into lower mantle

Messaggio da Marco E. Ciriotti » mer 21 ott, 2015 21:25

Prossima pubblicazione.

Referenza:
▪ Bindi, L., Tamarova, A., Bobrov, A.V., Sirotkina, E.A., Tschauner, O., Walter, M.J., Irifune, T. (2016): Incorporation of high amounts of Na in ringwoodite: Possible implications for transport of alkali into lower mantle. American Mineralogist, 101, (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: 24004
Iscritto il: ven 25 giu, 2004 11:31
Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
Contatta:

Re: Incorporation of high amounts of Na in ringwoodite: Possible implications for transport of alkali into lower mantle

Messaggio da Marco E. Ciriotti » mar 02 feb, 2016 19:02

Pubblicazione effettuata.

Referenza:
▪ Bindi, L., Tamarova, A., Bobrov, A.V., Sirotkina, E.A., Tschauner, O., Walter, M.J., Irifune, T. (2016): Incorporation of high amounts of Na in ringwoodite: Possible implications for transport of alkali into lower mantle. American Mineralogist, 101, 483-486.

Abstract:
Here we report on the coexistence between Na-rich ringwoodite and bridgmanite in the system MgSiO3-Na2CO3-Al2O3 at 24 GPa and 1700 °C. In our experiments ringwoodite incorporates up to 4.4 wt% Na2O, with Na entering the octahedral site together with Si, according to the mechanism: Mg2+ → 2/3Na+ + ⅓Si4+. The volume of the unit cell increases along with the Na content. A similar behavior is observed for the unit-cell volume of Na-bearing bridgmanite, although the mechanism of Na incorporation into this structure remains unknown because of the lack of sufficient crystallographic data. Na2O is compatible in ringwoodite relative to bridgmanite with a partition coefficient (D) of 5 (+5/−4), but is incompatible in ringwoodite relative to carbonate-rich melt/fluid, with the D value ranging between 0.5 and 0.1. Al is highly enriched in bridgmanite relative to the other coexisting phases. Carbonatitic melt metasomatism in the deep transition zone may lead to local Na-enrichment, and ringwoodite may be an important host for Na in the deep transition zone. Subsequent convection or subduction of metasomatized mantle may lead to enrichment of alkaline elements in the upper and lower mantle.
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 4 ospiti