کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4714621 1353978 2008 20 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Englacial tephrostratigraphy of Erebus volcano, Antarctica
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
Englacial tephrostratigraphy of Erebus volcano, Antarctica
چکیده انگلیسی

A tephrostratigraphy for Erebus volcano is presented, including tephra composition, stratigraphy, and eruption mechanism. Tephra from Erebus were collected from glacial ice and firn. Scanning electron microscope images of the ash morphologies help determine their eruption mechanisms The tephra resulted mainly from phreatomagmatic eruptions with fewer from Strombolian eruptions. Tephra having mixed phreatomagmatic–Strombolian origins are common. Two tephra deposited on the East Antarctic ice sheet, ~ 200 km from Erebus, resulted from Plinian and phreatomagmatic eruptions. Glass droplets in some tephra indicate that these shards were produced in both phreatomagmatic and Strombolian eruptions. A budding ash morphology results from small spheres quenched during the process of hydrodynamically splitting off from a parent melt globule. Clustered and rare single xenocrystic analcime crystals, undifferentiated zeolites, and clay are likely accidental clasts entrained from a hydrothermal system present prior to eruption. The phonolite compositions of glass shards confirm Erebus volcano as the eruptive source. The glasses show subtle trends in composition, which correlate with stratigraphic position. Trace element analyses of bulk tephra samples show slight differences that reflect varying feldspar contents.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Volcanology and Geothermal Research - Volume 177, Issue 3, 10 November 2008, Pages 549–568
نویسندگان
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