This is an important result that has implications for colonizing process (discussed below).More radiocarbon dating of short-lived materials from islands lacking enough Class 1 dates for robust chronologies (Gambier, Tuamotus, Australs, Northern Cooks, Kermadec, Norfolk, and Chathams; Fig. In addition, closer scrutiny of dates at the older end of the Class 1 age ranges may also increase the precision of estimates for initial colonization.To accomplish this, it is necessary to be conservative in evaluating the usefulness of data.
In contrast, Class 2–3 dates, which are based on materials that have a high risk of imprecision and/or inaccuracy, have a larger spread of ages, and these are often used to support longer chronologies in the region. Our LAEM and our EAEM for initial colonization are listed below each island group and are represented by the yellow band.
) Estimates for the timing of colonization for East Polynesian archipelagos or islands. ( The proportion of radiocarbon-dated sample materials in each overall reliability class is shown in Fig. Class 1 dates are dominated by short-lived plant materials (such as small twigs, leaves, and seeds) in contrast to Class 2 and 3 dates, which are dominated by long-lived plant remains and unidentified charcoal, sample types that are often unreliable, as they can introduce substantial error through in-built age.
One approach is to evaluate dates within their individual and comparative stratigraphic levels according to criteria of “chronometric hygiene” (11, 12) and build from those results toward a regional overview; but this method can be subjective, and it is impractical when dealing with very large databases, as is the case here.
Instead we have chosen a “top-down” approach to evaluate the entire archaeological radiocarbon database for East Polynesia as a single entity.
This allows radiocarbon dates, irrespective of stratigraphic context, to be categorized according to accuracy and precision, and for patterns of age and distribution of colonization to be sought accordingly upon the most reliable dated materials.