Palaeoseasonality investigations at the mouth of the Pleasant River (J43/1)

Abstract

Excavations at the mouth of the Pleasant River (J43/1) between 1991 and 1993 produced faunal and artefactual assemblages from at least three periods of activity. The earliest of these activity periods, dated to the fourteenth century, is contemporary with occupation at the nearby Shag Mouth site. Later occupations occurred during the fifteenth and sixteenth centuries.

This project considers the seasonality of prehistoric occupation on the 1.9 hectare dune site through an analysis of seasonally scheduled stress structures within the exoskeleton of New Zealand's common estuarine cockle, Austrovenus stutchburyi (Wood 1828). A modern control collection enabled the calibration of seasonal growth phenomena with calendrical time. Large population samples were necessary to model the considerable variation in seasonal growth rates evident within shellfish beds. Assemblages of Austrovenus stutchburyi from archaeological contexts were related to the modern analogue to obtain season of death estimates to within three months accuracy.

Six phases of prehistoric activity from four excavated areas on the dune were seasonally dated. Four of these occupations derive from what is described as a lower site component. This early period of activity on the dune occurred during the fourteenth century while the remaining two seasonally dated occupation phases were of fifteenth or sixteenth century origin. The results indicate that the earliest occupations on the dune occurred in all seasons. During this time subsistence was geared around the exploitation of big-game species (moa and sea mammals). One of these earliest occupations appears to have spanned at least one year. Later phases of activity were more seasonally restricted and evidenced considerably reduced exploitation of big-game species. It is argued that changing seasonal patterns of occupation on the dune reflect changing strategies of economic adaptation necessitated by dwindling supplies of preferred big-game species.