50 RUDDOCK 
(2) the method is destructive, thus the sample was on non-artefact material 
only. 
The results of this preliminary sort, and the samples chosen for XRF analysis are 
shown in Table 1. 
As a control on both elemental characterisation of the likely sources and the 
analytical method, obsidian from known localities, for which abundant sample was 
available, was also analysed. This was in response to the fact that only two of the 
samples to be sourced were of >10 g weight. By running multiple analyses of the 
known samples (including runs <10 g) the effect of lowered sample size (if any) could 
be assessed. The control rocks were taken from the reference collection of the 
Department of Anthropology, University of Auckland, and from two source areas: 
(i) Great Barrier Island (grey obsidian) — #680/4 (Te Ahumata), #679/26 
(Awana), #2935; and, 
(ii) Mayor Island (green obsidian) — #504, #1514/2. 
Mayor Island is a well documented source for green obsidian in New Zealand 
(Ward 1972). The Great Barrier Island source was suggested by Louise Furey (pers. 
comm.), and has been cited in the literature as a major obsidian source for the 
Auckland area (Fox 1982; Ward 1974). 
Table 1. Preliminary sort and sample selection of obsidian flakes from the Westfield (R11/ 
898) site. 
OO 
Sample size Sample analysed Percentage 
(ne eS _ 
LAYER | 64 pieces 
green 15 pieces not suitable (24.%) OCCUPATION II 
grey 49 pieces #246 (12.7 g) (76.6%) 
LAYER 2 20 pieces 
green 6 pieces #54 (7.14 g) (30%) 
grey 14 pieces #66 (5.05 g) (70%) 
OCCUPATION I 
LAYER 3 83 pieces 
green 23 pieces #105 (5.14 g) (27.7%) 
grey 60 pieces #46 (11.28 g) (72.3% 
NO LAYER 84 pieces 
green 25 pieces #444 (3.89 g) 
grey 59 pieces #379 (6.66 g) 
Total sample size = 252, green = 69 (27.4%), grey = 183 (72.6%). 
ee eS SS 00S 
Analytical procedure 
The procedure used was that used for the geochemical analysis of rocks by the 
Department of Geology, University of Auckland. All the materials analysed were 
