The distribution of nickel, cobalt, gallium, palladium and gold in iron meteorites

摘要: Abstract The concentrations of nickel, cobalt, gallium, palladium and gold have been determined in 45 iron meteorites including representatives from all structural classes. Gallium was determined, addition, two specimens troilite the metallic phase pallasites. analytical procedures characteristics studied are described detail. It is found that most fall into three distinct classes, each class possessing a fairly narrow range gallium concentrations: Class I, 40–100 ppm Ga; II, 20 III, 2 Ga. Analysis structures, nickel contents distributions leads to same divisions. All hexahedrites, nickel-poor ataxites coarse coarsest octahedrites possess levels corresponding I. Medium split between Classes I II approximate ratio 1:2. fine finest which posses 7·5% 8·5% III. conclusions might be drawn these observations discussed.