The composional and dynamic evolution of a large-volume felsic system (Gran Canaria)

点击翻译按钮获取中文摘要

Two main processes to explain the origin of highly evolved volcanic rocks on oceanic islands (rhyolites to phonolites) have been proposed for over 100 years: (1) crystal fractionation of basaltic magmas and (2) partial melting of crustal rocks of basaltic derivation and (3) a combination of these mechanisms. Gran Canaria, the paradigmatic endmember of oceanic bimodal basaltic - evolved volcanism, has erupted >100 km3 of practically exclusively felsic volcanics for >6 million years, represents a unique case history for documenting boundary conditions for the generation of a broad spectrum of evolved magmas. Rock units from 3 targets representing the very early, an intermediate and late stage of felsic volcanism will be subjected to thorough lithological, compositional/petrological and temporal analysis to provide a solid database on which to build a broader analytical strategy as well as a synthesis of the results of several decades of work on individual volcanic units.