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Concentration of major and trace elements have been estimated for six samples of intrusive and five samples of volcanic rocks. Major elements were determined by X–ray fluorescence spectroscopy (XRF) using a Siemens SRS–3000 instrument in the Laboratorio Universitario de Geoquímica Isotópica (LUGIS), UNAM, using procedures of Lozano–Santa Cruz et al. (1995) and Verma et al. (1996). Trace element concentrations were obtained by inductively coupled plasma mass spectrometry (ICP–MS) at the Centro de Geociencias of Juriquilla, UNAM, using a Thermo Series Xii instrument, and procedure of Mori et al. (2007). Details of the measurements are given in the following section and in Table A3 of the electronic supplement.