During April 29th- May 3rd， Professor A. E. Williams-Jones from McGill University was invited to visit Institute of Geochemistry, CAS.

Prof. A. E. Williams-Jones is a fellow of Royal Society of Canada, a full professor of McGill University. His research is devoted mainly to understanding the genesis of hydrothermal mineral deposits through a combination of field-based, experimental and theoretical methods. Deposits investigated include porphyry Cu and Mo, pegmatite-, greisens- and vein-hosted Sn-W, epithermal/mesothermal Au-Ag, epithermal Sb and Hg, and granite/pegmatite- and carbonatite-hosted rare metals (REE, Li, Be, Zr,Y). Up to now, He has published over 200 papers in the international journals, he was awarded with Mentorship medal, Distinguished Lecturer and Logan medal et al., for his distinguished achievement in Canadian earth science and sustained and inspirational mentorship of students, colleagues and employees.

Prof. A. E. Williams-Jones presented a talk titled ”The Rare Earth Elements - A Tale of Plumes, Melts and Hydrothermal Fluids” on April 30th, in which he introduced the discovering history, application of REE in modern life, and the REE minerals and distribution of REE deposits in the worlds.

He presented the REE deposit located in Strange Lake with details. From the evidence of mineralogical phase relationships, fluid/melt inclusions, the distribution of REE and Zr in pegmatite, and the solubility of REE in hydrothermal system, the path of REE mobilisation was reconstructed and the model of REE accumulation was given. After peralkaline granitic melt evolved, primary REE were dissolved as pH plunged and were re-precipitated as LREE and finally HREE minerals with the changing of temperature, the oxygen fugacity and pH in response to progressive fluid-rock interaction.

The presentation was greatly appreciated by the researchers and graduate students, and followed by the lively interactive discussions.

In addition, on the afternoon of May 1st and May 2nd, Prof. A. E. Williams-Jones discussed some academic issues with the researchers and graduate students.

Professor A. E. Williams-Jones presenting the talk

(By Prof. SHANG Linbo's group)