LAUSR

When studying indigenous sites, especially sacred sites such as burials, the needs and wishes of the indigenous people are paramount; the site integrity must be respected and the site must be left intact and undisturbed. Non-invasive, non-destructive geophysical imaging is well suited to such investigations, but suspicion within indigenous communities because of past transgressions are a barrier to widespread use; scepticism is not uncommon, but we always managed to convince the sceptics. We present an overview of results from 10 Maori (indigenous peoples of New Zealand) sites in the South Island of New Zealand: 1 historic burial site, 6 modern burial sites that also had historical use, 1 historic battle site, 1 prehistoric site that may have been a burial site, and 1 prehistoric site used for food storage that was tapu (sacred). Our approach was to let them ask us to delineate areas of importance, e.g., old burial sites. There are, naturally, processes and protocols, cultural and technical, that we followed. The sites comprised a range of lithologies and soil types: 1 site where clay soil overlay limestone; 5 sites where loess (airborne silt) overlay basalt; 1 set of inland silty soil sites; 1 site on peat soils overlying sandy gravels; and 2 sites in coastal sands. The geophysical responses of the sites cluster into three groups: Horizontal loop electromagnetics (HLEM) and magnetic field methods worked well for the clay soil site, and once the effects of the conductive clay response were removed by filtering, ground penetrating radar (GPR) worked well. HLEM and magnetic results were good to equivocal on the silty and peaty sites, whereas GPR excelled at delineating anomalous features, particularly burials, which yielded clear characteristic diffraction responses. Finally, results for coastal sand sites were disappointing. Such sites appear to be too dynamic to yield useful results.