Intra-quarry variability is an important issue largely overlooked when conducting lithic provenance studies. While researchers often acknowledge that variability occurs, most have failed to assess the impact it can have on sourcing studies. This is especially important because many quarries are ‘characterised’ by only a few samples. A case study from the South Molle Island Quarry, Queensland, illustrates the impact that sampling and intra-quarry variability has on lithic provenance studies. Petrographic results show that areas within the quarry differ in alteration patterns, textures, and phenocryst assemblages. 40Ar/39Ar geochronology dated the quarry at around 94 Ma, but was unable to differentiate temporally-distinct areas within the quarry. Geochemical results showed that ICP-OES/MS analysis produced more accurate results than XRF, and was able to detect areas within the quarry that differed chemically. Artefacts were analysed using XRF, which proved problematic; it was not possible to source them to either the quarry or specific areas. The study, however, illustrates that it is possible to source artefacts to areas within a quarry using geochemical and petrographic characteristics, allowing provenance studies to produce more detailed information about prehistoric quarry use.