Martin Okrusch was born in 1934 in Guben, Germany, and studied Geosciences at the Free University of Berlin and the University of Würzburg, Bavaria. After having obtained his doctoral degree in 1961 and his Dr. rer. nat. habil. in 1968, he worked as a guest researcher at the University of California at Berkeley in 1968/1969 and became an associate professor at the University of Cologne in 1970. He was a full professor at the Technical University of Braunschweig from 1972 to 1982, and at the University of Würzburg from 1982 until his retirement in 2000. Since then he has continued to work on research projects in metamorphic and igneous petrology. Hartwig Frimmel, born in 1960 in Linz, Austria, received his PhD in Geology and Petrology from the University of Vienna in 1987. Since 2004 he has been a full professor at the University of Würzburg, Bavaria, where he holds the Chair in Geodynamics and Geomaterials Research. He is an honorary research associate at the University of CapeTown, South Africa, where he rose from lecturer to associate professor between 1989 and 2004. From 1998 to 2004 he was the leader of the Earth Science subprogramme of the South African National Antarctic Programme. He is a former president of the Society for Geology Applied to Mineral Deposits (SGA) and advisor at the national and European level on matters concerning mineral deposits. His main research interests range from economic geology, metamorphic petrology, Precambrian palaeoclimate and palaeogeography, to sedimentary geochemistry and the role of early life in metallogenesis.