Quartz and Magnetite: Oxygen-18-Oxygen-16 Fractionation in Metamorphosed Biwabik Iron Formation

Abstract

Oxygen-18-oxygen-16 fractionation of coexisting quartz and magnetite from the Biwabik iron formation varies as a function of distance of the sample from an intrusive contact. This isotope fractionation is related to observed mineralogic variations and compared with a theoretical heat-flow model.