Original paper
Discussion on the use of δ - Δ diagram in interpreting stable isotope data
Zheng, Yong-Fei
European Journal of Mineralogy Volume 4 Number 3 (1992), p. 635 - 644
27 references
published: Jun 4, 1992
manuscript accepted: Nov 25, 1991
manuscript received: May 29, 1991
DOI: 10.1127/ejm/4/3/0635
Abstract
Abstract The geometric nature of δ - Δ diagram is examined and data from some natural systems are reappraised in order to prove the usefulness of such a diagram in interpreting the stable isotope composition of coexisting mineral pairs which have contrasting isotopic behaviors. When a closed system of more than two phases (or species) is taken into account in representing the conversation of mass in δ - Δ space, no simple geochemical meaning can be derived from the intercept and slopes of correlation arrays. It is shown that contrasting correlation arrays on the δ - Δ diagram may indicate disequilibrium isotope exchange under relatively closed system conditions. On the other hand, correlation arrays with slope » 1 on a δ - δ diagram suggest equilibrium isotope exchange under open system conditions, and therefore fractionation Δ - values are capable of providing an isotopic geothermometry
Keywords
carbon • oxygen • sulfur • isotopic ratios • graphical representation • equilibrium • disequilibrium • metamorphic rocks • hydrothermal ore deposits