While also using the international geologic time scale, many nations - especially those with isolated and therefore non-standard prehistories - use their own system of dividing geologic time into epochs and faunal stages.
In New Zealand, these epochs and stages use local place names (mainly Maori in origin) back to the Permian. Prior to this time, they largely use the same terms as used in the Australian geologic time scale, and are not divided into epochs. In practice, these early terms are rarely used, as most New Zealand geology is of more recent origin. In all cases, New Zealand uses the same periods as used internationally; it is only the subdivisions of these periods that have been renamed. Very few epochs and stages cross international period boundaries. Of those that do, almost all are within the Cenozoic Era.
Though the New Zealand geologic time scale has not been formally adopted, it has become widely used by New Zealand earth scientists, geologists and palaeontologists since its proposal by J. S. Crampton in 1995.
A standard abbreviation is also used for these epochs and stages, mostly in the form Xx where the first letter is the initial letter of the epoch and the second (lower-case) letter is the initial letter of the stage. These are listed alongside the stage names in the list below.
Currently, we are in the Haweran stage of the Wanganui epoch. The Haweran, which started some 340,000 years ago, is named after the North Island town of Hawera.
List of New Zealand geologic time epochs and stages
Times given indicate the start of the respective stages and epochs. Several of these stages are further divided into upper and lower or upper, middle, and lower, although this has not been noted below unless unique names have been given to these sub-stages. As with the international geologic scale, these epochs and stages are largely named for locales where rock dating from these time periods is in evidence, with stage names predominantly but not always named for locales close to their epoch's namesake site. Where known, these places are also linked in the list below.
Stages prior to the beginning of the Carboniferous Period use either international (Devonian/Silurian) or Australian (Ordovician/Cambrian) geologic stage names; very little New Zealand rock is known from these geologic periods.