Dacite lava including fresh and oxidized biotite phenocryst. Oxygen fugacity in Terayama dacite magma, Osaka, Japan.
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چکیده
منابع مشابه
Excess Argon within Mineral Concentrates from the New Dacite Lava Dome at Mount St. Helens Volcano.indd
The conventional K-Ar dating method was applied to the 1986 dacite flow from the new lava dome at Mount St. Helens, Washington. Porphyritic dacite which solidified on the surface of the lava dome in 1986 gives a whole rock K-Ar “age” of 0.35±0.05 million years (Ma). Mineral concentrates from the dacite which formed ins 1986 give K-Ar “ages” from 0.34±0.06 Ma (feldspar-glass concentrate) to 2.8±...
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ژورنال
عنوان ژورنال: JOURNAL OF MINERALOGY, PETROLOGY AND ECONOMIC GEOLOGY
سال: 1993
ISSN: 0914-9783,1881-3275
DOI: 10.2465/ganko.88.339