NEW DATA ON MINERALOGY AND GEOCHEMISTRY OF APATITE-MAGNETITE ORES OF THE TOMTOR MASSIF, NORTHEAST OF THE SIBERIAN PLATFORM
Keywords:
Siberian platform, Tomtor, ultrabasic alkaline carbonatite complex, kamaforites, foskorites, apatite, magnetite, carbonate, rare-earth elements (REE), gold, platinum.Abstract
New data is given on mineralogy and geochemistry of kamaforites (apatite-magnetite ores) of Tomtor massif, including oxide-silicate main and secondary
minerals, sulfide and carbonate rare minerals including accessory rare-earth phases. Ore gold was for the first time found in the carbonate of apatitemagnetite ores and in the pyrite of nepheline syenites within Tomtor massif. Elevated U, Th and Sc concentrations allowing to consider them as the
source of high concentrations in carbonatites and their crusts of weathering were found in apatitemagnetite ores. Based on study results of texturestructure features, mineralogy and geochemistry of apatite-magnetite ores, the sequence of complex ores mineral formation at the magmatic and postmagmatic process stages synchronous with the main carbonatite phase of Tomtor massif formation is offered.