The geochemistry of thallium

摘要: Abstract A new analytical method has been developed for the determination of thallium in silicates. Numerous analyses minerals and rocks have made, to establish distribution mode occurrence thallium, especially common rocks. double-arc spectrochemical was used, giving a precision ± 20% sensitivity limit close 0.05 ppm thallium. Thallium occurs igneous by substitution potassium. Its geochemical behaviour closely resembles rubidium, so that it is concentrated residual magmas occur notable amounts pegmatitic potassium minerals. It also certain sulphides. During erosion goes into true solution as univalent cation, but removed from adsorption clays. Under strong oxidising conditions accumulates manganiferous deposits; reducing environment concentrates slight degree carbonaceous shales. figure 1·3 calculated crustal abundance balance discussed. Rubidium-thallium ratios various materials are computed, their significance Some aspects geochemistry shown be relevant fundamental questions petrogenesis.