Table 4.  Major element analyses by the NL Geological Survey Laboratory:
instrumentation and digestion methods, listed by year (from Kerr et al., 1994).

Year	Instrument (Digestion)
1972	1990 reanalysis by ICP-OES (LiBO2 fusion, HF/HCl/H3BO3 digestion)
1978-1979	AAS (HF/HCl/H3BO3 digestion)
1980-1984	AAS (LiBO2 fusion, HF/HCl/H3BO3 digestion)
1985-present	ICP-OES (LiBO2 fusion, HF/HCl/H3BO3 digestion)