Evidence for pressure dependence of the peak position in the REE mineral/melt partition patterns of clinopyroxene

Journal Article · Wed Apr 01 00:00:00 EST 1992 · Geochimica et Cosmochimica Acta; (United States)

DOI:https://doi.org/10.1016/0016-7037(92)90221-4· OSTI ID:5299281

Liu, C Q ^[1]; Masuda, A; Shimizu, H ^[2]; Xie, G H ^[3]

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1. Inst. of Physical and Chemical Research, Saitama (Japan) Univ. of Tokyo (Japan)
2. Univ. of Tokyo (Japan)
3. Academia Sinica, Guiyang (China)

Major element compositions, REE abundances, and strontium and neodymium isotope ratios were measured for three megacrysts of garnet, five of clinopyroxene, one of amphibole and the host alkali basalts from two volcanoes in northeastern China. Strontium and neodymium isotopic data and major elements (Fe and Mg) indicate a cognate origin of megacrysts and host lavas. Logarithmic values of REE partition coefficients for these minerals were found to vary parabolically with ionic radius, and hence the REEs in these three minerals are considered to substitute primarily into only one lattice site of each mineral. The ionic radius (optimum radius) defined by the position of peak top of the parabola is variable. Based on the REE partition coefficient data for both experimental and naturally existing clinopyroxene/melt pairs, the change of the optimum radius may be interpreted to be mainly pressure dependent.

• OSTI ID: 5299281
• Journal Information: Geochimica et Cosmochimica Acta; (United States), Vol. 56:4; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
AMPHIBOLE
CHEMICAL COMPOSITION
CRYSTAL LATTICES
ISOTOPE RATIO
BASALT
PETROGENESIS
CHINA
GARNETS
PYROXENES
ELEMENT ABUNDANCE
EQUILIBRIUM
GEOCHEMISTRY
MAGMA
NEODYMIUM ISOTOPES
PARTITION
PARTITION FUNCTIONS
PHASE STUDIES
PRESSURE DEPENDENCE
PRESSURE EFFECTS
RARE EARTH COMPOUNDS
SILICATE MINERALS
STRONTIUM ISOTOPES
VOLCANOES
ABUNDANCE
ALKALINE EARTH ISOTOPES
ASIA
CHEMISTRY
CRYSTAL STRUCTURE
FUNCTIONS
IGNEOUS ROCKS
ISOTOPES
MINERALS
OXYGEN COMPOUNDS
ROCKS
SILICATES
SILICON COMPOUNDS
VOLCANIC ROCKS
580000* - Geosciences