THE GEOCHEMISTRY 0F APATITE

Abstract

A detailed review is presented of previous work in ths apatite mineral series. A precise d.c. arc spectrographic method was developed for the analysis of minor and trace elements in apatite, and 46 apatite samples from igneous pegmatitic and metamorphic environments analysed. The data were analysed statistically using an electronic computer. Apatite from all environments is enriched relative to the lithosphere in Ce, La, Y, and Sr, and apatite from many granite pegmatites is a Iso enriched in Mn. The incorporation of trace elements is discussed from the point of view of lattice position and structural and environmental control. A mechanism is proposed to account for the high Y/Ce + La ratio in apatite from granite pegmatites. The variation of trace elements within a single large crystal of apatite was examined by analysing 102 core samples taken from a section within the crystal. The inhomogeneity of trace element content is discussed in the light of crystal growth. habit modification and geochemical significance.