The age of a site is determined by radiocarbon dating which measures the time at which the sample being analysed died. Radiocarbon dating will not give a calendar date, rather it indicates a range within which there is a high statistical probability that the sample ceased living. By choosing samples which correlate closely with the archaeological activity, for example, shellfish in a midden or twigs from a fireplace, an age range for that activity is obtained. Because of the short time-scale and the lack of distinctive markers in Maori culture, there is little in the greater part of New Zealand's settlement history which can be used to assess the age of sites without resorting to radiocarbon dating techniques. The exception is the presence of distinctive artefact types closely resembling East Polynesian styles and therefore assigned to the early period of settlement of New Zealand. The remains of sea mammals, moa and other extinct birds in a site also contribute to a classification of 'early' (pre-1500 AD).
The settlement of Hauraki, in keeping with dates for other regions in New Zealand, is condensed into a relatively short time-scale of about 500-600 years before European arrival. While there have been previous claims made for occupation of 1000 years, there is no evidence to validate the assertions. Anomalous radiocarbon dates of an early age can be individually discounted on the basis of the type of wood used (often driftwood used in fires, long-lived species or heartwood posts) and in several instances old results on shell suggest that natural beach deposits rather than food remains have been dated. The reliable dates all fit comfortably after 1250-1300 AD (Fig. 8). The Polynesian settlers explored and settled most areas within a century. Although the earliest dates for settlement are found on the east coast of the Coromandel Peninsula and islands of the Hauraki Gulf, the Hauraki Plains have evidence of occupation at Oruarangi in the 15th century and the Tamaki area was also well known at that time. No sites of an early age are known from the North Shore and northern coast, but occasional finds of adzes of an early type suggest activity here also.
A model of settlement based on initial rapid exploration of the country has been proposed (Anderson 1991). Thus major stone resources of basalt, argillite, chert and obsidian are found in all known early sites. After initial exploration people may have become more locally focussed and developed territorial rights, for example, the
