Mineral inclusions are not immutable: Evidence of post-entrapment thermally-induced shape change of quartz in garnet

database, nuove specie, discrediti,
ridefinizioni, classificazioni, ecc.
Rispondi
Avatar utente
Marco E. Ciriotti
Messaggi: 29308
Iscritto il: ven 25 giu, 2004 11:31
Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
Contatta:

Mineral inclusions are not immutable: Evidence of post-entrapment thermally-induced shape change of quartz in garnet

Messaggio da Marco E. Ciriotti » sab 14 mag, 2022 10:31

Referenza:
▪ Cesare, B., Parisatto, M., Mancini, L., Peruzzo, L., Franceschi, M., Tacchetto, T., Reddy, S.M., Spiess, R. Nestola, F., Marone, F. (2020): Mineral inclusions are not immutable: Evidence of post-entrapment thermally-induced shape change of quartz in garnet. Earth and Planetary Sciences Letters, 555, 116708.

Abstract:
Sheltered inside crystals, mineral inclusions preserve crucial information on the geological history of our planet. These inclusions allow estimation of the pressure and temperature trajectories of metamorphic rocks, but also can tell about rock mineralogy, provenance, and geodynamic and petrogenetic processes. This information is recovered under the axiom that mineral inclusions have remained immutable objects that do not change shape after their entrapment. Conversely, we show that post-entrapment shape modifications do occur in high-T rocks from granulite-facies conditions. Here we analyze the shape and orientation of quartz inclusions within garnet, a common metamorphic mineral. Our data reveal a progressive change in shape from irregularly-shaped forms in rocks formed at T<550 °C, to combined dodecahedron and icositetrahedron geometries imposed by the host garnet in granulites equilibrated at T>750 °C. Lack of fluid at the quartz-garnet phase boundary indicates that inclusion shape change occurs by thermally-induced grain boundary diffusion, driven by the minimization of the surface energy of the host-inclusion system. Since inclusions acquire a negative crystal shape after entrapment, our discovery redefines the conceptual framework for the application of elastic thermobarometry, and motivates a reevaluation of the criteria for mineral inclusion syngenesis in metamorphic rocks.
Marco E. Ciriotti

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


Avatar utente
Marco E. Ciriotti
Messaggi: 29308
Iscritto il: ven 25 giu, 2004 11:31
Località: via San Pietro, 55 I-10073 Devesi/Cirié TO - Italy
Contatta:

Re: Mineral inclusions are not immutable: Evidence of post-entrapment thermally-induced shape change of quartz in garnet

Messaggio da Marco E. Ciriotti » sab 14 mag, 2022 18:07

Sì, certo.
Te lo passo non appena lo avrò dagli autori.
Eccolo qui allegato.
2021_Cesare_et_al_EPSL(1).pdf
(3.45 MiB) Scaricato 8 volte
Marco E. Ciriotti

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

Avatar utente
Michiel
Messaggi: 685
Iscritto il: lun 25 feb, 2008 13:41
Località: Monaco di Baviera

Re: Mineral inclusions are not immutable: Evidence of post-entrapment thermally-induced shape change of quartz in garnet

Messaggio da Michiel » sab 14 mag, 2022 22:08

Molto interessante, grazie Marco.
Michiel Desittere

Benedetti siano gli istanti
e i millimetri
e le ombre delle piccole cose.
(Fernando Pessoa)

Ferdinando Giovine
Messaggi: 407
Iscritto il: sab 27 apr, 2013 13:32

Re: Mineral inclusions are not immutable: Evidence of post-entrapment thermally-induced shape change of quartz in garnet

Messaggio da Ferdinando Giovine » dom 15 mag, 2022 9:15

Marco E. Ciriotti ha scritto:
sab 14 mag, 2022 18:07
Sì, certo.
Te lo passo non appena lo avrò dagli autori.
Eccolo qui allegato.

2021_Cesare_et_al_EPSL(1).pdf
Studierò :D

Rispondi

Chi c’è in linea

Visitano il forum: Bing [Bot] e 4 ospiti