Techniques of Investigation
Recording: Information about a site can be gained from local residents, particularly those with an interest in Maori history, from examination of aerial photographs, or from actual field work (often all three methods are used, in this order). In the field a detailed survey is made of the surface features of the site, using a map, tape measure, theodolite, camera, compass, and so on. The locality of the site, its type (hilltop pa, headland pa, island pa, etc.), main dimensions, proximity and relationship to other sites, the state of preservation and possibility of further damage, are all noted. If possible, the Maori name of the area and any historical references to it are obtained, together with a record of any artefact collections made from there.
Field recording is being done by small groups throughout the country. All the information collected is kept in regional files, with a duplicate set in a central file in Wellington.
Excavations are carried out on relatively few sites, due to the limited time, labour, and money available to the New Zealand archaeologist. The usual practice is to excavate 10-ft squares of ground, leaving a baulk of earth between each to act as a record of the stratigraphy (i.e., the positions and relationships) of the layers removed from the squares. Material inside the square is removed very carefully layer by layer, often a fraction of an inch at a time. The characteristics and contents of each layer are recorded in a field notebook, sketch plans are constantly drawn, and samples of important materials (bone, shell, charcoal, stone, pumice, etc.) are kept for further, and more careful identification and analysis.
“Emergency” excavations are sometimes necessary. Most sites are slowly being destroyed; banks, walls, ditches, pits, and canals are being levelled through natural processes of erosion, and earth structures and soil layers are being disturbed by tree-root penetration. Man, however, is the most destructive agent of all. In many places in New Zealand he has used shell middens for surfacing roads; in the Auckland area he has quarried into fortified volcanic cones, and in the South Island the hydro-electric development of the upper Waitaki River has flooded caves containing rock paintings. Road construction and house-building activities uncover and destroy countless sites throughout the country. The farmer discs and ploughs burial grounds, pa, working floors, etc., obliterating all stratification. When, however, such a threatened site is heard about in time, a salvage excavation is usually made to obtain as much information as possible before the site is finally lost. In Auckland, in particular, there is some concern over the amount of destruction occurring; a 1962 survey showed that of 267 recorded sites in the area, 204 were so badly destroyed that further investigations would not be worth while.