Polimorfos de alta presión de sílice en las impactitas de Chicxulub, México: resultados de la espectrometría Raman

Abstract

Preliminary results of Raman spectrometry applied in the search of high pressure silica polymorphs in the impact breccia of the Chicxulub crater, Mexico, are presented. The study was carried directly on a polished slab. The lines corresponding to coesite (one major near to 520 cm^-1 and others of minor intensity, about 119, 178, 272 cm^-1) and to stishovite (231, 587, 752 cm^-1) were observed in some of the spectra. These results allow us to infer the presence of high pressure SiO₂ polymorphs in the Chicxulub impactites. This evidence lends support to the origin by impact of the structure.