Editorial

In 2009 the Journal enters its 50^th year of publication –our "golden anniversary"! This is certainly good cause for celebrationand we will be doing just that in various ways throughout theyear. Volume 1 was published in February 1960. The very first paperby P.J. Wyllie and O.F. Tuttle on "The system CaO-CO₂-H₂O andthe origin of carbonatites" [J.Petrology 1:1-46] provided anidea for a special symposium at the 2009 Goldschmidt conference"Challenges to Our Volatile