The Role of High Field Strength Cations in Silicate Melts

1991 ◽  
pp. 152-191 ◽  
Author(s):  
Paul C. Hess
Keyword(s):  
Field Strength ◽  
High Field ◽  
Silicate Melts ◽  
High Field Strength

Corundum (sapphire) and zircon relationships, Lava Plains gem fields, NE Australia: Integrated mineralogy, geochemistry, age determination, genesis and geographical typing

2015 ◽  
Vol 79 (3) ◽  
pp. 545-581 ◽  
Author(s):  
F. L. Sutherland ◽  
R. R. Coenraads ◽  
A. Abduriyim ◽  
S. Meffre ◽  
P. W. O. Hoskin ◽  
...  
Keyword(s):  
Rare Earth ◽  
Field Strength ◽  
Rare Earth Elements ◽  
Trace Element ◽  
High Field ◽  
Age Determination ◽  
Silicate Melts ◽  
Geochemical Evolution ◽  
High Field Strength ◽  
Zircon Formation

AbstractGem minerals at Lava Plains, northeast Queensland, offer further insights into mantle-crustal gemformation under young basalt fields. Combined mineralogy, U-Pb age determination, oxygen isotope and petrological data on megacrysts and meta-aluminosilicate xenoliths establish a geochemical evolution in sapphire, zircon formation between 5 to 2 Ma. Sapphire megacrysts with magmatic signatures (Fe/Mg ∼100–1000, Ga/Mg 3–18) grew with ∼3 Ma micro-zircons of both mantle (δ18O 4.5–5.6%) and crustal (δ18O 9.5–10.1‰) affinities. Zircon megacrysts (3±1 Ma) show mantle and crustal characteristics, but most grew at crustal temperatures (600–800°C). Xenolith studies suggest hydrous silicate melts and fluids initiated from amphibolized mantle infiltrated into kyanite+sapphire granulitic crust (800°C, 0.7 GPa). This metasomatized the sapphire (Fe/Mg ∼50–120, Ga/Mg ∼3–11), left relict metastable sillimanite-corundum-quartz and produced minerals enriched in high field strength, large ion lithophile and rare earth elements. The gem suite suggests a syenitic parentage before its basaltic transport. Geographical trace-element typing of the sapphire megacrysts against other eastern Australian sapphires suggests a phonolitic involvement.

Combining SPARSE fMRI Designs with SENSE at High Field Strength

2006 ◽  
Vol 178 (01) ◽  
Author(s):  
L Scheef ◽  
M Daamen ◽  
U Fehse ◽  
MW Landsberg ◽  
DO Granath ◽  
...  
Keyword(s):  
Field Strength ◽  
High Field ◽  
High Field Strength

High-field-strength STIR imaging: limitations

1989 ◽  
Vol 153 (5) ◽  
pp. 1104-1105
Author(s):  
BA Porter
Keyword(s):  
Field Strength ◽  
High Field ◽  
High Field Strength

Comparison of High-Field-Strength Versus Low-Field-Strength MRI of the Shoulder

2003 ◽  
Vol 181 (5) ◽  
pp. 1211-1215 ◽  
Author(s):  
Thomas Magee ◽  
Marc Shapiro ◽  
David Williams
Keyword(s):  
Field Strength ◽  
High Field ◽  
High Field Strength ◽  
Low Field
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