Geodata science (GDS) is an interdisciplinary field in which geoscience data are mined for us to well understand the origin, evolution and future of our Earth and planet with prediction and assessment of its resources, environments, and natural hazards. The data chain of GDS involves collecting geosciences data, mining geoinformation, discovering geo-knowledge, and making spatial decisions. There are three groups of GDS methods for exploring and mining geoscience data including data statistics, data mining, and data insight and prediction. A case study on geochemical exploration data mapping was conducted to demonstrate the powerful use of GDS. The results show that GDS is a new research paradigm for exploring the spatial association of geochemical patterns, mining elemental association, and recognizing geochemical anomalies associated with mineralization via geo-computation and geo-visualization techniques in support of mineral exploration. •GDS is the science to studying and mining geospatial patterns•GDS is a new research paradigm in geoscience and can be used for geochemical mapping in support of mineral exploration•GDC can reveal the spatial association, identify the elemental association, and recognize geochemical anomalies.