Application of X-ray mapping to the interpretation of silicate mineral assemblages

Abstract

Metamorphism, magmatism and the formation of ore deposits imply the often sequential (re)crystallization of mineral phases. Hence, an intensive study of the textural-mineralogical development of the rocks greatly increases the understanding of the processes involved in their formation, such as growth and dissolution. The invention of the electron probe microanalyzer (EPMA) in 1951 by Raymond Castaing entailed a significant contribution to the chemical characterization of the mineral phases. One of the EPMA applications that should be not underestimated is the X-ray intensity mapping of areas of interest in thin sections. This technique allows obtaining two-dimensional spatial distribution maps of several measured elements in their textural context that, together with the development of appropriate software, allows deciphering the processes involved in their formation and evolution. In this contribution we show X-ray maps applied to silicate mineral assemblages. To do so, we study different lithologies and illustrate the importance of this technique in the textural-chemical analysis of minerals.