Search results for "Uraninite"

THE REDISTRIBUTION OF RARE-EARTH ELEMENTS IN SECONDARY MINERALS OF HYDROTHERMAL VEINS, SCHWARZWALD, SOUTHWESTERN GERMANY

2011

Minerals of the rare-earth elements (REE) occur as supergene phases in the Schwarzwald ore district, southwestern Germany. They form by alteration of hydrothermal fluorite – barite – quartz – carbonate veins with various associations, including Cu– Pb, Pb–Zn and Co–Bi–Ag–U assemblages in sandstones, gneisses and granites. The REE minerals, including mixite-group minerals ([REE,Bi,Ca,Pb]Cu 6 (AsO 4 ,AsO 3 OH) 3 OH 6 •3H 2 O), rhabdophane and churchite (REEPO 4 •H 2 O and REEPO 4 •2H 2 O), chukhrovite (Ca 3 REEAl 2 SO 4 F 13 •10H 2 O) and bastnasite (REECO 3 F), were analyzed by electron microprobe and LA–ICP–MS. In addition, REE concentrations in secondary fluorite, calcite and Mn oxides cog…