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Origin and evolution of Cenozoic magmatism of Sardinia (Italy). A combined isotopic (Sr-Nd-Pb-O-Hf-Os) and petrological view, LITHOS (2013), doi: 10.1016/j.lithos.2013.08.022 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT

Matrix glass and melt inclusions in phenocrysts from pantellerite lavas of the Boseti volcanic complex, Ethiopia, record extreme fractionation of peralkaline silicic magma, with Al 2 O 3 contents as low as 2.3 wt.%, FeO* contents up to 17 wt.% and SiO 2 contents~65 wt.%. The new data, and published data for natural and experimental glasses, suggest that the effective minimum composition for peralkaline silicic magmas has~5 wt.% Al 2 O 3 , 13 wt.% FeO* and 66±2 wt.% SiO 2 . The dominant fractionating assemblage is alkali feldspar + fayalite + hedenbergite + oxides±quartz. Feldspar -melt relationships indicate that the feldspar is close to the minimum on the albiteorthoclase solid solution loop through the entire crystallization history. There is petrographic, mineralogical and geochemical evidence that magma mixing may have been a common process in the Boseti rhyolites.