12:00 PM - 1:00 PM
We report the first detailed study of Si isotopes in zircon, coupled with simultaneous detection of O isotope ratios, to better understand the relationship between crustal weathering and recycling. Current knowledge about Si isotopes shows their potential to complement and enhance that understanding because weathering of the crust typically results in a residuum with lower 30Si (where δ30Si is the deviation in ‰ of a sample’s 30Si/28Si ratio to that of a standard) when compared to ‘fresh’ igneous material. Samples explored include zircons from S-, I-, and A-type Phanerozoic granitoids, and detrital zircons from the Jack Hills. We also explore the relationship between the δ30Si value of individual minerals and the whole rock by quantifying high temperature Si isotope fractionations by experiment.