Fig. S1: <sup>39</sup>Ar–<sup>40</sup>Ar step heating results. Chemical and petrographic fingerprinting of volcanic ashes as a tool for high-resolution stratigraphy of the upper Miocene Pisco Formation (Peru) BosioGiulia GioncadaAnna MalinvernoElisa Di CelmaClaudio VillaIgor M. CataldiGiuseppe GariboldiKaren CollaretaAlberto UrbinaMario BianucciGiovanni 2018 Fig. S1: <sup>39</sup>Ar–<sup>40</sup>Ar age spectrum of the biotite separate of the tephra layer LB-T11.