Chapter 8 Volcanism, magmatism, volcano-tectonics and sea-level fluctuations in the geological history of Filicudi (western Aeolian archipelago)

Abstract

AbstractThe geological history of Filicudi in the Middle–Late Pleistocene (246–29 ka) is described by four successive Epochs of activity separated by quiescence stages, erosional episodes during marine isotope stage (MIS) 7 and MIS 5 and the Vallechiesa sector collapse. The partially overlapping Casa Ficarisi, Fossa Felci and Chiumento stratocones and the Monte Guardia scoria cone are built up under control of the WNW–ESE regional tectonic trend, with a subsequent progressive south-eastwards shift and chemical differentiation towards the Monte Terrione and Capo Graziano domes. The Monte Montagnola dome (64 ka) and Case dello Zucco Grande pyroclastics (<56 ka) are the youngest products, together with the Canna neck (29 ka) of an independent volcanic centre offshore of Filicudi. Filicudi rocks are calc-alkaline basalts, basaltic andesites and high-K andesites with minor dacites. Incompatible elements increase from basalts to dacites, with much scatter. Sr, Nd and Pb isotopes show moderate variations. δ18O‰ of clinopyroxene phenocrysts ranges from +5.37 to +6.20, and shows the highest values in the mafic rocks. Geochemical data suggest a complex interplay of different evolution processes (fractional crystallization, crustal assimilation and mixing) for the various eruptive centres of Filicudi. Variable incompatible element ratios of mafic rocks are suggested to reflect source heterogeneity.DVD:The 10 000 scale geological map of Filicudi is included on the DVD in the printed book and can also be accessed online at http://www.geolsoc.org.uk/Memoir37-electronic. Also included are a full geochemical dataset and xenolith data for Filicudi.