کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
8911252 1638265 2018 82 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Conduit processes during the climactic phase of the Shinmoe-dake 2011 eruption (Japan): Insights into intermittent explosive activity and transition in eruption style of andesitic magma
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
Conduit processes during the climactic phase of the Shinmoe-dake 2011 eruption (Japan): Insights into intermittent explosive activity and transition in eruption style of andesitic magma
چکیده انگلیسی
The crystal size distribution (CSD) of plagioclase microlites constrains the syneruptive branching (i.e., a point of divergence) in ascent rate and eruption style, which occurred after the start of microlite crystallization. The CSDs of the different samples show differences only in small crystal sizes; slope at these size fractions is smallest for low-density (<2.0 g/cm3) pyroclasts from all eruptive phases, medium for high-density pyroclasts and lava (>2.0 g/cm3) of the January 28 and February 1 events, and greatest for high-density pyroclasts (>2.0 g/cm3) of the third sub-Plinian event. We propose, based on the similarity in CSD, that the shallow magma-feeding system was common for the two craters active during the January 28 explosive-effusive hybrid activity, where the Vulcanian event and emplacement of lava of the later February 1 event occurred in different parts of the original crater. The samples have variable plagioclase microlite number densities (1.4 × 105-3.5 × 106 mm−3), based on variations in small crystal sizes among different CSDs. This variability resulted not only from the usual increasing trend in number density with increasing degree of undercooling, but also the decreasing trend associated with the strong undercooling during explosive eruptions.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Volcanology and Geothermal Research - Volume 358, 1 June 2018, Pages 87-104
نویسندگان
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