Mechanical sampling, conventional dissolution and chemical separation, followed by analysis using the TIMS (Thermal Ionisation Mass Spectrometry), is one of the best methods for highly accurate and precise determinations of Sr isotopic compositions in most geological materials over a wide range of Sr concentrations. Recent technological improvements have provided the opportunity to analyze Sr isotopic compositions at the scale of individual crystals and along core to rim transects of single minerals. Sr isotopic ratio variations, recorded from core to rim of a mineral grain, reflect the progressive changes, if any, in the composition of the magma from which the mineral has crystallized [e.g. Davidson et al., 2001, 2007; Francalanci et al., 2005]. Therefore, the relationship between...