High-pressure and high-temperature stability of chlorite and 23-Å phase in the natural chlorite and synthetic MASH system - 09/05/19
pages | 9 |
Iconographies | 6 |
Vidéos | 0 |
Autres | 0 |
Abstract |
A series of experiments was conducted on the decomposition of natural and chemically mixed chlorites to examine the stable hydrous phases in the MgO–FeO–Al2O3–SiO2–H2O (MFASH) system under 5–12GPa and 700–1100°C. The upper pressure and temperature limits of the stability region of chlorite are consistent with those observed in previous studies. The hydrous aluminum bearing pyroxene (phase HAPY) and Mg-sursassite (Sur) were observed just above the temperature stability region of chlorite (Chl); clinohumite (cHm) was observed coexisting with phase HAPY at 6GPa and 800°C and coexisting with the 23-Å phase at 7GPa and 800°C, which may suggest the transportation of water through Chl→(HAPY→cHm)→23-Å phase along a relatively warm slab. The 23-Å phase has a wider stability region in the pure MASH system (up to 12GPa and 1100°C) than it does in the MFASH system (7–10GPa, up to 1000°C). The stability of the 23-Å phase beyond the chlorite breakdown pressure indicates that it may play an important role in transporting water into the deep Earth and even into the mantle transition zone.
Le texte complet de cet article est disponible en PDF.Keywords : Chlorite, 23-Å phase, MASH, Hydrous phase, Subduction zone
Plan
Vol 351 - N° 2-3
P. 104-112 - février 2019 Retour au numéroBienvenue sur EM-consulte, la référence des professionnels de santé.
L’accès au texte intégral de cet article nécessite un abonnement.
Bienvenue sur EM-consulte, la référence des professionnels de santé.
L’achat d’article à l’unité est indisponible à l’heure actuelle.
Déjà abonné à cette revue ?