F-rich phlogopite stability in ultra-high-temperature metapelites from the Napier Complex, East Antarctica
-
Y. Motoyoshi
Abstract
Fluorine-rich phlogopite [F content up to ~8 wt%; F/(F + OH) ~0.9] in ultra-high-temperature metapelitic granulites from the Napier Complex, East Antarctica is associated with aluminous orthopyroxene, osumilite, sapphirine, garnet, and quartz. Textural relationships imply that some of the phlogopite is of primary origin and stable under ultra-high-temperature conditions. This is in accord with recent experimental evidence on the stability of F-rich phlogopite. Because the F-rich phlogopite also occurs as rounded inclusions in aluminous orthopyroxene (Al2O3 up to 12.8 wt%), sapphirine, osumilite, and garnet, it is inferred that the ultra-high-temperature mineral assemblages, which includes these minerals formed during prograde partial melting reactions at the expense of phlogopite, at a depth of less than 30 km. Thus the coarse-grained peak metamorphic assemblages formed below 9 kbar, and there is no evidence the rocks underwent any significant degree of decompression during or soon after peak metamorphic conditions. The phlogopite breakdown reactions we suggest on the basis of textural arguments differ from those postulated from experiments on F-free systems.
© 2015 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- First-principles modeling of the infrared spectrum of kaolinite
- Determination of the limiting fictive temperature of silicate glasses from calorimetric and dilatometric methods: Application to low-temperature liquid volume measurements
- Enthalpies of formation of tremolite and talc by high-temperature solution calorimetry – a consistent picture
- Evidence for an I2/a to Imab phase transition in the silica polymorph moganite at ~570 K
- Thermal decomposition of rhombohedral KClO3 from 29–76 kilobars and implications for the molar volume of fluid oxygen at high pressures
- High-pressure behavior of clinochlore
- Structure and elasticity of wadsleyite at high pressures
- Determination of the fluid–absent solidus and supersolidus phase relationships of MORB-derived amphibolites in the range 4–14 kbar
- F-rich phlogopite stability in ultra-high-temperature metapelites from the Napier Complex, East Antarctica
- Instability of Al2SiO5 “triple-point” assemblages in muscovite+biotite+quartz-bearing metapelites, with implications
- Stability of osumilite coexisting with spinel solid solution in metapelitic granulites at high oxygen fugacity
- Geikielite exsolution in spinel
- Aeromagnetic anomalies, magnetic petrology, and rock magnetism of hemo-ilmenite- and magnetite-rich cumulate rocks from the Sokndal Region, South Rogaland, Norway
- Minor element chemistry of hemo-ilmenite and magnetite in cumulate rocks from the Sokndal Region, South Rogaland, Norway
- Crystal structure analysis of synthetic Ca4Fe1.5Al17.67O32: A high-pressure, spinel-related phase
- Crystal structure of phase X, a high pressure alkali-rich hydrous silicate and its anhydrous equivalent
- Fluoro-edenite from Biancavilla (Catania, Sicily, Italy): Crystal chemistry of a new amphibole end-member
- Description and crystal structure of turtmannite, a new mineral with a 68 Å period related to mcgovernite
- The crystal structure of low melanophlogite
- Crystal structures of Na and K aluminate mullites
- From mastodon ivory to gemstone: The origin of turquoise color in odontolite
- Letters. Elasticity of single-crystal calcite and rhodochrosite by Brillouin spectroscopy
- Ikaite, CaCO3·6H2O: Cold comfort for glendonites as paleothermometers
Articles in the same Issue
- First-principles modeling of the infrared spectrum of kaolinite
- Determination of the limiting fictive temperature of silicate glasses from calorimetric and dilatometric methods: Application to low-temperature liquid volume measurements
- Enthalpies of formation of tremolite and talc by high-temperature solution calorimetry – a consistent picture
- Evidence for an I2/a to Imab phase transition in the silica polymorph moganite at ~570 K
- Thermal decomposition of rhombohedral KClO3 from 29–76 kilobars and implications for the molar volume of fluid oxygen at high pressures
- High-pressure behavior of clinochlore
- Structure and elasticity of wadsleyite at high pressures
- Determination of the fluid–absent solidus and supersolidus phase relationships of MORB-derived amphibolites in the range 4–14 kbar
- F-rich phlogopite stability in ultra-high-temperature metapelites from the Napier Complex, East Antarctica
- Instability of Al2SiO5 “triple-point” assemblages in muscovite+biotite+quartz-bearing metapelites, with implications
- Stability of osumilite coexisting with spinel solid solution in metapelitic granulites at high oxygen fugacity
- Geikielite exsolution in spinel
- Aeromagnetic anomalies, magnetic petrology, and rock magnetism of hemo-ilmenite- and magnetite-rich cumulate rocks from the Sokndal Region, South Rogaland, Norway
- Minor element chemistry of hemo-ilmenite and magnetite in cumulate rocks from the Sokndal Region, South Rogaland, Norway
- Crystal structure analysis of synthetic Ca4Fe1.5Al17.67O32: A high-pressure, spinel-related phase
- Crystal structure of phase X, a high pressure alkali-rich hydrous silicate and its anhydrous equivalent
- Fluoro-edenite from Biancavilla (Catania, Sicily, Italy): Crystal chemistry of a new amphibole end-member
- Description and crystal structure of turtmannite, a new mineral with a 68 Å period related to mcgovernite
- The crystal structure of low melanophlogite
- Crystal structures of Na and K aluminate mullites
- From mastodon ivory to gemstone: The origin of turquoise color in odontolite
- Letters. Elasticity of single-crystal calcite and rhodochrosite by Brillouin spectroscopy
- Ikaite, CaCO3·6H2O: Cold comfort for glendonites as paleothermometers
