File 3: Robust laser ablation Lu–Hf dating of apatite: an empirical evaluation

Isochron and weighted mean plots for the Lu–Hf matrix-correction standard (OD-306) and secondary standards HR-1 and Bamble-1. MSWD, mean squared weighted deviation; n, number of analyses; P(χ²), Chi-squared probability for a single data population. Where required (i.e. insufficient spread along the isochron), the isochrons were anchored to an initial ¹⁷⁷Hf/¹⁷⁶Hf ratio of 3.55 ± 0.05 (see text).