Prof. A.E. William-Jones Department of Earth and Planetary Sciences McGill University
This presentation starts by recounting the history of the discovery of the rare earth elements, describing their uses and reporting some of their basic characteristics. It then goes on to examine the processes that lead to their eventual concentration in the Earth’s crust, noting the importance of low degrees of partial melting of mantle materials and metasomatism in the production of REE-fertile magmas. The presentation closes with a description and discussion of two contrasting world class Canadian deposits in which fractional crystallization and magma immiscibility, respectively, were dominant in concentrating the REE and hydrothermal alteration enhanced their potential for exploitation.