New experimental evidence on cluster-type vaporization of feldspars

Resumo

This paper reports experimental data on the investigation of the chemical composition of condensed silicate matter produced during the high-temperature pulse vaporization of feldspars. The experiments simulated the conditions of vaporization accompanying a high-velocity impact. Samples of albite, bytownite, calcic and sodic labradorite, and sanidine were used in the experiments. The investigation of the condensate layers obtained in the experiments included the determination of element distribution and structural characteristics of the materials using layer-by-layer X-ray photoelectron spectroscopy. It was shown that the vaporization of the samples occurred mainly through the release of complex atom–molecule groups referred to as clusters. “Nepheline,” “wollastonite,” and “sillimanite” clusters were identified as characteristic groups. The thermodynamic evaluation of melt composition at temperatures up to 5000 K performed using the Magma program confirmed high activities of these components in feldspar melts.