TRACE AND RARE-EARTH ELEMENTS IN CASSITERITE - SOURCES OF COMPONENTS FOR THE TIN DEPOSITS OF THE MOLE GRANITE, AUSTRALIA

Trace and rare earth elements have been determined for cassiterite from deposits associated with the Mole Granite and hosted by granite, metasediments and metavolcanics. The SIGMA-REE of cassiterite is controlled by the SIGMA-REE of the the ore fluid and the rocks through which this fluid circulated. The REE distribution factor and SIGMA-LREE/HREE value of cassiterite is strongly influenced by the associated mineral assemblage, the fluid chemistry and the crystal chemical characteristics of the host mineral. Cassiterite from deposits hosted by granite have trace and rare earth element characteristics similar to those determined for the Mole Granite. Cassiterite from deposits hosted by metasediments or acid volcanics have most trace and rare earth element characteristics similar to those of the enclosing rocks and some characteristics similar to the Mole Granite. The ore fluid had chemical components derived from the parental granite and components acquired by passage through the metamorphosed aureole.