Micro-Raman spectroscopic study of El Gasco pumice, western Spain

Abstract

A micro-Raman spectroscopic study of pumice materials from El Gasco (Sierra de Gata, Spain) has been performed for the first time. The obtained spectra allow the precise identification of the minerals, quartz, haematite, magnetite, ilmenite, rutile and anatase, in general agreement with results obtained by complementary techniques of X-Ray Diffraction (XRD) and Electron Microprobe. Also, fayalite and ferroan ringwoodite have been identified. The presence of high-pressure polymorphs indicates that the pumice rocks were subjected to high-pressure conditions quite similar to those observed in shock-induced molten and recrystallised materials, such as some meteorites and impact-related rocks.