کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4714897 1638452 2008 14 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Geochemistry of Telichian (Silurian) K-bentonites in Estonia and Latvia
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
Geochemistry of Telichian (Silurian) K-bentonites in Estonia and Latvia
چکیده انگلیسی

In the Telychian section of Estonia and Latvia K-bentonites from 45 volcanic eruptions were discovered. The thickness of K-bentonite interbeds varies from a few millimetres to 20 cm. The sodium component concentration in sanidine phenocrysts measured by XRD ranges from 20 to 48 mol% and was used for establishing correlations. The Ti, Zr, Nb, Th and Sr concentrations and ratios show temporal trends indicating fractional crystallization in magma chambers. The analysis of biotite phenocrysts revealed magnesium and iron rich biotites in bentonites. Synthesis of these geochemical data enabled a classification of bentonites into seven geochemical types, which probably originate from seven different volcanic sources. Isopach schemes indicate ash transport from the west and north-west directions.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Volcanology and Geothermal Research - Volume 171, Issues 1–2, 30 March 2008, Pages 45–58
نویسندگان
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