Natural Titanite Reference Materials for In Situ U-Pb and Sm-Nd Isotopic Measurements by LA-(MC)-ICP-MS

Titanite is a common accessory mineral that preferentially incorporates considerable amounts of U and light rare earth elements in its structure, making it a versatile mineral for in situ U-Pb dating and Sm-Nd isotopic measurement. Here, we present in situ U-Pb ages and Sm-Nd isotope measurement results for four well-known titanite reference materials (Khan, BLR-1, OLT1 and MKED1) and eight titanite crystals that could be considered potential reference material candidates (Ontario, YQ-82, T3, T4, TLS-36, NW-IOA, Pakistan and C253), with ages ranging from ~ 20 Ma to ~ 1840 Ma. Results indicate that BLR-1, OLT1, Ontario, MKED1 and T3 titanite have relatively homogeneous Sm-Nd isotopes and low common Pb and thus can serve as primary reference materials for U-Pb and Sm-Nd microanalysis. YQ-82 and T4 titanite can be used as secondary reference materials for in situ U-Pb analysis because of their low common Pb. However, internal structures and mineral inclusions in YQ-82 will require careful selection of suitable target domains. Pakistan titanite is almost concordant with an age of 21 Ma and can be used as a reference material when dating Cenozoic titanite samples.