In 2012, the second edition 1:250 000 Geological Map of New Zealand series was completed. Named "QMAP" (for "Quarter-million MAP"), it produced 21 geological maps covering mainland New Zealand. In 2014 the 21 individual QMAP datasets were merged and published as this collection of digital datasets.

The original published geological maps (QMAPs) were intended for a wide audience, with even treatment of older and younger rock units. The emphasis was on deposits rather than landforms. As a general rule, the uppermost deposit or rock unit more than 5 metres thick was been depicted, and veneers of soils, tephra, loess and scree were commonly omitted. The composite mapping units were defined by one or more of age, lithostratigraphy, lithology, geochemical affinity (for plutons) and metamorphic grade. Metamorphic rock units were portrayed in terms of their known or inferred protolith age; Haast Schist rocks had overprints depicting their textural metamorphic grade.

The mapping frame for the majority of datasets is defined as 'surface geology', but some are either 'base of overlying geology' or 'top of basement'. The data should not be used at scales beyond that for which it was prepared. The spatial accuracy is estimated to be no better than +/- 250 m.

For more detailed metadata for the 1:1 250 000 Geological Map of New Zealand (1st edition) visit https://data.gns.cri.nz/metadata/srv/eng/catalog.search#/metadata/26306E9E-EC27-4909-AEDD-B3320FEC47E4