Strontium isotopic evidence for the genesis of volcanic rocks from Japanese Island arcs.
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چکیده
منابع مشابه
Isotopic composition of strontium in volcanic rocks from oahu.
Analysis of several well-documented specimens from each of the three volcanic series on Oahu gives the following mean ratios of Sr(87) to Sr(86): the Waianae series, 0.7030 +/- 0.00010 (sigma); the Koolau series, 0.70385+/- 0.00009 (sigma); and the Honolulu series, 0.7029 ++/- 0.00006 ( sigma). The mean ratio of Sr(87) to Sr(86) of the Koolau series specimens is significantly higher than the me...
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Study of lamproites from Leucite Hills, Wyoming, indicates that the isotopic compositions of some specimens have been modified due to the alteration and/or the presence of secondary carbonate impurities within the whole rocks. Leachate test shows that while phlogopite lamproites are not affected by secondary processes, the transitional madupitic lamproites from Middle Table Mountain and on...
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The origin of analcite-bearing lavas and potassic volcanic rocks is controversial in the geological record. Two main hypotheses are either primary analcite or replacement pseudomorphous of leucite. Spectacular large (5 cm) euhedral trapezohedra occur as single crystals of analcite in tephriphonolite lavas from Nadik area. Based on the following evidences the large analcite trapezohedra from Nad...
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Oxygen isotope data are reported for clinopyroxene phenocrysts from volcanic rock samples from Filicudi island, Italy, with the aim of investigating mechanisms of magma evolution and mantle source characteristics in a continental arc volcano. Filicudi rocks range from calc-alkaline basalt to high-K andesite and dacite. Mafic rocks have MgO 6-7 wt%, Mg# 60, Ni < 50 ppm and Cr < 200 ppm, suggesti...
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ژورنال
عنوان ژورنال: Journal of Geography (Chigaku Zasshi)
سال: 1986
ISSN: 0022-135X,1884-0884
DOI: 10.5026/jgeography.95.4_254