کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4717911 | 1638776 | 2006 | 14 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Experimental constraints on pre-eruption conditions of pantelleritic magmas: Evidence from the Eburru complex, Kenya Rift
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موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
ژئوشیمی و پترولوژی
پیش نمایش صفحه اول مقاله
![عکس صفحه اول مقاله: Experimental constraints on pre-eruption conditions of pantelleritic magmas: Evidence from the Eburru complex, Kenya Rift Experimental constraints on pre-eruption conditions of pantelleritic magmas: Evidence from the Eburru complex, Kenya Rift](/preview/png/4717911.png)
چکیده انگلیسی
The phase relationships and compositions of a pantellerite from the Eburru complex in the Kenya Rift Valley have been determined at 150 MPa and under reducing conditions, 2 log units below the Ni-NiO solid buffer. The effects of temperature and melt water content on phase relationships have been explored. Alkali feldspar and quartz crystallise alone at temperatures above 700 °C, irrespective of melt water content. Below 700 °C, sodic amphibole and clinopyroxene also crystallise; the amphibole being the liquidus phase under water-rich conditions. The coexistence of amphibole phenocrysts with alkali feldspar and quartz in a crystal-poor pantellerite implies temperatures below 700 °C and melt water contents higher than 4 wt.%, possibly up to 5-6 wt.%. Pantellerites have lower liquidus temperatures than associated comendites, which supports a parent-daughter relationship between the two magma types. The melts produced in the experiments extend the compositional trend displayed by the natural rock series, and reproduce some extreme compositions occasionally observed in alkaline volcanic series, with FeOâ contents above 12 wt.% and Na2O contents approaching 10 wt.%. Pantellerites are therefore the true near-minimum melt compositions of alkaline oversaturated magma series.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Lithos - Volume 91, Issues 1â4, October 2006, Pages 95-108
Journal: Lithos - Volume 91, Issues 1â4, October 2006, Pages 95-108
نویسندگان
Bruno Scaillet, Ray Macdonald,