Abstract:
Carbonate rocks frequently contain some silicate minerals and various xenoliths. Calcareous mudstone is also widely distributed. There is no report of practical analytical method of mixtures of silicate and carbonate by XRF spectrometer. Therefore, we must invent the precise analytical method ranging from silicate to carbonaceous rocks.In this study, we used low dilution glass beads (sample : flux ratio of 1 : 2) and tried to analyze wide compositional range for such major elements as SiO2, TiO2, Al2O3, MnO, MgO, CaO, Na2O, K2O and P2O5 with trace elements (V, Cr, Ni, Rb, Sr, Ba, Y, Zr, Nb) by XRF spectrometer. In order to analyze ranging from wide compositional samples, we made some standards; such as mixed standards, additive standards and synthetic standards. The mixed standards consist of the mixture of two GSJ standards. The next ones are weighed-reagents added GSJ standards. The beads of weighed-reagents added SiO2 powder are synthetic standards. In addition to them, we used some GSJ standard samples. The glass beads of high CaO content samples are not transparent. We therefore developed the method to make clear grass beads by adding a small amount of SiO2 powder to the samples. As a result, we could perform precise XRF analyses for wide compositional ranges from silicate to carbonate rocks.
