In Situ Oxygen Isotope Determination in Serpentine Minerals by Ion Microprobe: Reference Materials and Applications to Ultrahigh‐Pressure Serpentinites

We present the first investigation of in situ oxygen isotopes in serpentine minerals by sensitive high‐resolution ion microprobe ( SHRIMP ). Chemically homogeneous samples of antigorite (δ 18 O = 8.30 ± 0.12‰), chrysotile (δ 18 O = 4.37 ± 0.02‰) and lizardite (δ 18 O = 5.26 ± 0.20‰) analysed by laser fluorination are identified as potential reference materials. They were analysed by SHRIMP to assess their homogeneity compared with the San Carlos...