Simon's research strengths are in the application of fieldwork, petrology, geochemistry and geochronology to the study of continental crustal evolution. All projects are international in scope, with current research being concentrated in Brazil, China, Egypt, Thailand, Vietnam and Western Australia. An overarching theme to this research is the desire to understand the range of processes that contribute to crustal growth. Most of the work over the past decade has involved the application of U-Pb SHRIMP (zircon, baddeleyite and perovskite) and Ar-Ar (hornblende, biotite and muscovite) geochronology to key lithologies in the Yilgarn and North China cratons. The necessity to interpret complex zircon structures at the single crystal level has led to collaborative investigations on oxygen isotope distribution with Prof John Valley and his group at the University of Wisconsin-Madison (using the Cameca 1270 and 1280 ion microprobes) and on hafnium isotope systematics with Prof Fuyuan Wu at the Chinese Academy of Sciences-Beijing (using LA-MC-ICP-MS).