The use of 18O/16O ratios to study the formation and chemical origin of coal

The ${}^{18}\text{O}{}^{16}\text{O}$ ratios of some New Zealand peat, lignite and coal samples were measured and compared with those of various coal precursors (cellulose, lignin and plant resins). The results showed that the major source of oxygen in all cases (except that of high rank coal) was from cellulose with the contribution from lignin and plant resins being insignificant.