52 RUDDOCK 
Table 2. Analytical resylts of obsidian from the Westfield site. 
ee 
Sample 680/4 679/26 2935 246 
a NOON 
Major elements — wt. % (elemental wt. %) 
SiO, 75.79 (35.4) 70.95 (33.2) 75.96 (35.5) 75.69 (35.4) 
TiO, 0.11 (659) 0.10 (599) 0.11 (659) 0.10 (599) 
Al,O,; 12.80 (3.39) 12.72 (3.37) 12.57 (3.33) 12.59 (3.33) 
Fe,0;* 1.47 1.67 1.42 1.37 
MnO 0.03 (232) 0.04 (310) 0.03 (232) 0.03 (232) 
MgO 0.17 0.12 0.15 0.20 
CaO 0.75 (0.54) 0.75 (0.54) 0.69 (0.49) 0.68 (0.49) 
Na,O 3.83 (1.42) 2.31 (0.85) 3.94 (1.46) 3.80 (1.41) 
K,O 4.69 (1.95) 4.63 (1.92) 4.80 (1.99) 4.83 (2.01) 
P,O; 0.03 0.02 0.03 0.02 
H,0° 0.03 1.02 0.18 0.15 
LOI 0.13 6.00 0.16 0.41 
Total 99.83 100.33 100.03 99.87 
Trace elements (ppm) 
Ba 513.3 737.9 441.3 445.7 
Rb 195.7 177.3 196.6 193.3 
Sr 29.5 28.6 21.4 22.7 
Pb 26.1 24.4 23.8 23.1 
Th 21.4 15.7 25.0 18.3 
Zr 142.0 194.3 132.3 133.6 
Y 33.1 46.1 36.8 37.3 
La 39.0 34.3 32.1 36.1 
Vv bdl bdl bdl pans 
Cr bdl bdl bdl bdl 
Ni bdl bdl bdl ae 
Cu 8.3 bdl TA 10.2 
Zn a5, 5 61.6 38.4 38.4 
ee eee cee 
Sample 66 46 379 1514/2 
eee See 
Major elements — wt. % (elemental wt. %) 
SiO, 75.82 (35.4) 76.41 (35.7) 75.92 (35.5) 73.54 (34.4) 
TiO, 0.11 (659) 0.12 (719) 0.10 (599) 0.23 (1379) 
Al,O3 12.62 (3.34) 12.70 (3.36) 12.88 (3.41) 10.48 (2.77) 
Fe,0;* 1.43 1.42 1.45 4.74 
MnO 0.02 (154) 0.03 (232) 0.03 (232) 0.10 (775) 
MgO 0.16 0.18 0.23 0.06 
CaO 0.69 (0.49) 0.68 (0.49) 0.76 (0.54) 0.21 (0.15) 
Na,O 4.01 (1.49) 3.88 (1.44) 3.90 (1.45) 5.84 (2.17) 
K,O 4.85 (2.01) 4.80 (1.99) 4.70 (1.95) 4.37 (1.81) 
PO; 0.03 0.02 0.03 0.02 
H,O0 0.11 0.02 0.04 0.02 
LOI 0.18 0.15 0.29 0.00 
Total 100.01 100.40 100.33 99.68 
