Oxygen isotopes in geology.

A critical survey has been conducted on the research done in oxygen isotopes. Only those aspects are considered which are of interest to the earth scientists. Oxygen isotopes have been used for geothermometric purposes and for rock genesis problems. The physical principles underlying these two lines of research are stressed. Assumptions which are usually implied are explicitly stated. It is shown that the influence of pressure on the equilibrium constant of oxygen isotope exchange reactions is only a minor one in comparison with the temperature influence. The significance of determined temperatures is discussed in the light of possible oxygen diffusion in silicates and carbonates. It is concluded that diffusion is usually neglected without justification. As far as data are available it is shown that diffusion can be responsible for many discrepancies between oxygen isotope temperatures and' temperatures derived by other means. Studies on the origin of rocks by means of oxygen isotopes are discussed. Attention is focussed on the Southern Californian batholith. The results of Taylor and Epstein's preliminary study of this batholith are interpreted here as evidence in favour of a metamorphic origin of this huge rock body.Science, Faculty ofPhysics and Astronomy, Department ofGraduat