Simultaneous Determination of delta O-18 and delta Cl-37 Isotopic Compositions and the Concentrations of F, Cl, and S in Apatite Using SIMS

Due to its ubiquity in rock types and ability to accommodate a wide range of trace elements, apatite is widely used to interpret magmatic evolution and track volatile elements in hydrothermal systems. Volatile elements and Cl-O isotopes make apatite an ideal mineral with which to record the chemical and textural signatures of geological processes. This study describes a new analytical procedure to obtain the F, Cl, and S contents and Cl and O isotopes simultaneously using secondary ion mass spectrometry (SIMS) within similar to 10 min of analysis time for each spot. The analytical precision of delta O-18 (2 SD (standard deviation) similar to 0.30 parts per thousand) and delta Cl-37 (2 SD similar to 0.20 parts per thousand) has no obvious trade-off compared with ordinary SIMS analysis. The new protocol is time-efficient and, more importantly, ensures the consistency of data sources. A set of apatite standards with different uses were determined using this new method to provide a complete set of recommended values.