Supplementary Material for Di Vincenzo et al., Dating low-grade deformation: role of lithology and strain partitioning on Ar isotope records in the Alpi Apuane of northern Apennines (Italy)

Table S1 - Electron microprobe (EMP) analyses EMP analyses of individual minerals were carried out using a Cameca SX-100 electron microprobe at Camparis laboratory in Paris (Table S1), in the following analytical conditions: beam current of 10 nA; acceleration voltage of 15 kV; beam diameter of 3 μm; analyzed elements: B, F, Na, Mg, Al, Si, Cl, K, Ca, Ti, Cr, Mn, Fe, Ba. Chemical formulas were calculated on the basis of O20(OH, F, Cl)4 (micas), O10(OH, F, Cl)4 (chloritoid), (CO3)2 (carbonates), 19 cations including B (tourmaline), O8 (feldspar) or O4 (magnetite).

Table S2 - 40Ar–39Ar step-heating and in-situ data Data were completed at IGG–CNR (Pisa, Italy). Data were performed by step-heating experiments on white mica separates (grain size 0.25–0.35 mm) and in-situ analyses on rock chips ~8.5 mm in diameter drilled from polished thick sections (~400 μm thick). Rock chips and the mineral separates, after cleaning by alternating methanol and deionized water, were wrapped in aluminum foil and irradiated along with the Fish Canyon Tuff sanidine (FCs) in the core of the TRIGA reactor at the University of Pavia (Italy) in two distinct batches, for 30 h (irradiation PAV-69) for step-heating analyses, and for 60 h (irradiation PAV-84) for samples analysed by the in-situ technique.