Article
Licensed
Unlicensed
Requires Authentication
Letter: Corundum + orthopyroxene ± spinel intergrowths in an ultrahigh-temperature Al-Mg granulite from the Southern Marginal Zone, Limpopo Belt, South Africa
-
G.A. Belyanin
,
H.M. Rajesh
Published/Copyright:
April 2, 2015
Abstract
We report the occurrence of unusual lamellar (random and regular subparallel) intergrowths of corundum and symplectic intergrowth of spinel with orthopyroxene in an ultrahigh-temperature Al-Mg granulite from the Southern Marginal Zone of the Limpopo Belt, South Africa. Separate compositions are suggested for the homogenous phase that might have existed prior to the formation of the two types of lamellar intergrowths of corundum with orthopyroxene. In the case of random lamellar corundum + orthopyroxene intergrowth, the estimated precursor composition is similar to Fe-Mg garnet, while, although speculative, an ultrahigh-Al orthopyroxene precursor is suggested to account for the exsolution nature of the unique regular subparallel corundum lamellae in orthopyroxene. Considering that the stability field of Fe-Mg-rich garnet relative to orthopyroxene + corundum extends to lower pressures, the estimated garnet composition (XMg = ~0.65) is most likely stable at low pressures of ~5 kbar. Such low pressures are further supported by the Fe-Mg-rich garnet compositional nature of the pre-spinel-intergrowth orthopyroxene. Given the rare preservation of the mineral assemblages typical of prograde metamorphism in granulite facies rocks, our discovery of corundum lamellar intergrowth with orthopyroxene from an ultrahigh-temperature Al-Mg granulite is unique.
Keywords: Corundum + orthopyroxene intergrowth; ultrahigh-temperature Al-Mg granulite; Fe- Mg-rich garnet; Limpopo Belt
Received: 2009-8-25
Accepted: 2009-9-8
Published Online: 2015-4-2
Published in Print: 2010-1-1
© 2015 by Walter de Gruyter Berlin/Boston
You are currently not able to access this content.
You are currently not able to access this content.
Articles in the same Issue
- Metamorphic ultrahigh-pressure tourmaline: Structure, chemistry, and correlations to P-T conditions
- Slavikite—Revision of chemical composition and crystal structure
- Anisotropic elasticity of jarosite: A high-P synchrotron XRD study
- Tourmaline of the elbaite-schorl series from the Himalaya Mine, Mesa Grande, California: A detailed investigation
- Characterization of Al-Si ordering state in an alkali feldspar using atom location by channeling-enhanced microanalysis (ALCHEMI)
- The relative stability of stoichiometrically related natural and synthetic double salts
- Free energy of formation of zircon based on solubility measurements at high temperature and pressure
- Structure refinement of a synthetic knorringite, Mg3(Cr0.8Mg0.1Si0.1)2(SiO4)3
- A mineral tracer toward high-resolution dust provenance on the Chinese Loess Plateau: SEM, TEM, and sulfur isotopes of sulfate inclusions in biotite
- High-resolution TEM study of jimthompsonite, chesterite, and chain-width disorder in Archean ultramafic rocks from Isua, West Greenland
- Retrograde hydration sequence in disordered Mg amphiboles: A TEM investigation
- Can electron energy-loss spectroscopy (EELS) be used to quantify hydrogen in minerals from the O K edge?
- Texture analysis of a turbostratically disordered Ca-montmorillonite
- Packing systematics of the silica polymorphs: The role played by O-O nonbonded interactions in the compression of quartz
- Calorimetric study of the surface energy of forsterite
- Crystallographic texture of the magnetite-hematite transformation: Evidence for topotactic relationships in natural samples from Quadrilátero Ferrífero, Brazil
- Semi-ordered crystalline structure of the Santa Olalla vermiculite inferred from X-ray powder diffraction
- Stishovite single-crystal growth and application to silicon self-diffusion measurements
- Density of dry peridotite magma at high pressure using an X-ray absorption method
- The crystal-structure and vacancy distribution in 6C pyrrhotite
- Thermal modification of hematite-ilmenite intergrowths in the Ecstall pluton, British Columbia, Canada
- A new Al-rich hydroxylian pseudorutile from Kalimantan, Indonesia
- Lapeyreite, Cu3O[AsO3(OH)]2·0.75H2O, a new mineral: Its description and crystal structure
- High P-T phase relation of magnesian (Mg0.7Fe0.3) staurolite compositon in the system FeO-MgO-Al2O3-SiO2-H2O: Implications for prograde high-pressure history of ultrahigh-temperature metamorphic rocks
- Letter: Hibonite-(Fe), (Fe,Mg)Al12O19, a new alteration mineral from the Allende meteorite
- Letter: Ion irradiation of the TiO2 polymorphs and cassiterite
- Letter: Corundum + orthopyroxene ± spinel intergrowths in an ultrahigh-temperature Al-Mg granulite from the Southern Marginal Zone, Limpopo Belt, South Africa
- Letter: Fe3+ spin transition in CaFe2O4 at high pressure
- Density functional theory and Monte Carlo study of octahedral cation ordering of Al/Fe/Mg cations in dioctahedral 2:1 phyllosilicates
Keywords for this article
Corundum + orthopyroxene intergrowth;
ultrahigh-temperature Al-Mg granulite;
Fe- Mg-rich garnet;
Limpopo Belt
Articles in the same Issue
- Metamorphic ultrahigh-pressure tourmaline: Structure, chemistry, and correlations to P-T conditions
- Slavikite—Revision of chemical composition and crystal structure
- Anisotropic elasticity of jarosite: A high-P synchrotron XRD study
- Tourmaline of the elbaite-schorl series from the Himalaya Mine, Mesa Grande, California: A detailed investigation
- Characterization of Al-Si ordering state in an alkali feldspar using atom location by channeling-enhanced microanalysis (ALCHEMI)
- The relative stability of stoichiometrically related natural and synthetic double salts
- Free energy of formation of zircon based on solubility measurements at high temperature and pressure
- Structure refinement of a synthetic knorringite, Mg3(Cr0.8Mg0.1Si0.1)2(SiO4)3
- A mineral tracer toward high-resolution dust provenance on the Chinese Loess Plateau: SEM, TEM, and sulfur isotopes of sulfate inclusions in biotite
- High-resolution TEM study of jimthompsonite, chesterite, and chain-width disorder in Archean ultramafic rocks from Isua, West Greenland
- Retrograde hydration sequence in disordered Mg amphiboles: A TEM investigation
- Can electron energy-loss spectroscopy (EELS) be used to quantify hydrogen in minerals from the O K edge?
- Texture analysis of a turbostratically disordered Ca-montmorillonite
- Packing systematics of the silica polymorphs: The role played by O-O nonbonded interactions in the compression of quartz
- Calorimetric study of the surface energy of forsterite
- Crystallographic texture of the magnetite-hematite transformation: Evidence for topotactic relationships in natural samples from Quadrilátero Ferrífero, Brazil
- Semi-ordered crystalline structure of the Santa Olalla vermiculite inferred from X-ray powder diffraction
- Stishovite single-crystal growth and application to silicon self-diffusion measurements
- Density of dry peridotite magma at high pressure using an X-ray absorption method
- The crystal-structure and vacancy distribution in 6C pyrrhotite
- Thermal modification of hematite-ilmenite intergrowths in the Ecstall pluton, British Columbia, Canada
- A new Al-rich hydroxylian pseudorutile from Kalimantan, Indonesia
- Lapeyreite, Cu3O[AsO3(OH)]2·0.75H2O, a new mineral: Its description and crystal structure
- High P-T phase relation of magnesian (Mg0.7Fe0.3) staurolite compositon in the system FeO-MgO-Al2O3-SiO2-H2O: Implications for prograde high-pressure history of ultrahigh-temperature metamorphic rocks
- Letter: Hibonite-(Fe), (Fe,Mg)Al12O19, a new alteration mineral from the Allende meteorite
- Letter: Ion irradiation of the TiO2 polymorphs and cassiterite
- Letter: Corundum + orthopyroxene ± spinel intergrowths in an ultrahigh-temperature Al-Mg granulite from the Southern Marginal Zone, Limpopo Belt, South Africa
- Letter: Fe3+ spin transition in CaFe2O4 at high pressure
- Density functional theory and Monte Carlo study of octahedral cation ordering of Al/Fe/Mg cations in dioctahedral 2:1 phyllosilicates
