Geochemical Investigations in Earth and Space Science: A Tribute to Isaac R. Kaplan is the written product of a technical session organized for the 2002 Geological Society of America in recognition of Isaac (Ian) Kaplan’s many contributions to various fields of geochemistry. This volume is a collection of 29 papers written by former students, post-doctoral researchers, friends and colleagues from countries all over the world (including Sweden, Japan, Taiwan, New Zealand, Australia, Israel and the United States)