PROTON MICROPROBE STUDY OF RARE EARTH ELEMENTS IN APATITE

A combination of proton microprobe induced X-ray emission and γ-ray emission are used to determine the major- and minor-element contents of fourteen apatite samples from various geologic environments. The chondrite-normalized distribution of the rare earth element (REE) shows light REE enrichment for the majority of samples. The apatite structure may not concentrate LREEs relative to the HREEs. The actual REE distribution in a particular apatite is often indicative of the chemical and physical conditions under which it formed.