抄録
Ore segregations of chromian spinels are located mainly in layered ultramaficmafic complexes and in ophiolite sequences. Numerous observations on compositional variability of chromites have been made, and various aspects of mineralizations such as genesis, stratigraphic position, tectonic setting, texture, and host rock are reflected in the major element chemistry of individual ore bodies. However, conventional geochemical classification schemes based on only a few components prove to be uncertain because of overlaps between groups.
Published microprobe data on the composition of more than 400 ore and accessory chromite grains from mineralized complexes of most of the important chrome-producing countries are evaluated by means of multivariate mathematical methods in order to reveal the relationships between mineral chemistry and other features of chromite deposits. Cluster analysis was used to separate, and non-linear mapping and principal components analysis to visualize natural geochemical classes. Multiple discriminant analyses based on different sets of groups led to plots enabling effective classifications of chromites.
