Geochemical mapping has long been a linchpin technology for mining and exploration, but the past decade has seen a rapid spread of this methodology to the areas of climate science, ecology, biogeochemistry, and forensic science (Bowen et al., 2009). This change has been in part technology-driven, with instrumentation and technology facilitating the development of large, spatially explicit geochemical datasets and the web-based distribution of large environmental datasets. In another sense, it has reflected an increased emphasis on research addressing regional, rather than local, challenges and the scaling-up of processes studied at small scales for assessment and prediction at national, continental, and global scales. For such studies, where geochemical data are of use for tracing material fluxes or monitoring Earth system processes, the application of spatial analysis to new types of geochemical data and new Earth science challenges has created a wealth of research opportunities. At the same time, these efforts have also revealed serious limitations with existing data availability and theoretical models that stand in the way of this work.