ИСТИНА |
Войти в систему Регистрация |
|
ИСТИНА ПсковГУ |
||
Partitioning of trace and rare-earth elements between mantle minerals and melts at high pressures and temperatures is of considerable importance for all geochemical models involving melting of the Earth's mantle.It is shown that bridgmanite and ferropericlase are enriched with HREEs. Pyrolite with carbonate is characterized by an increase in the partitioning coefficients for light rare elements. For calcium perovskite, on the contrary, light enrichment and depletion of heavy rare earths are observed. Partition coefficients (CaPrv/L) of REEs in calcium perovskite decrease with temperature. The results obtained indicate that under the conditions of the Earth’s lower mantle, trace and rare-earth elements may be accumulated not only in the CaSiO3 perovskite (Ringwood et al., 1988), but in ferropericlase and bridgmanite as well.