Porphyry deposits are a signature ore deposit type of magmatic arcs, and numerous examples have formed around the Pacific Rim. Porphyry deposits have distinctive geochemical and geophysical footprints that are centred on shallow crustal mineralising intrusive complexes. The footprints vary as a function of various parameters, including depth of erosion, protolith compositions and size of the hydrothermal system. When exploring for porphyry deposits, at shallow crustal levels, explorers must contend with lithocaps, domains of intense, texturally destructive, silicic, advanced argillic and argillic alteration that contain abundant pyrite. Lithocaps can form stratabound domain that extend for more than 10 km2 and may be more than 1 km thick. CITATION: Cooke, D R, Baker, M, Wilkinson, J J, Agnew, P, Gemmell, J B, Danyushevsky, L, Hollings, P and White, N C, 2019. New geochemical exploration tools to aid discovery of porphyry deposits a case study from Resolution, Arizona, in Proceedings PACRIM 2019, pp 1213 (The Australasian Institute of Mining and Metallurgy: Melbourne).