**Appendice I Building the Geodatabase**

### **Figure A1.**

*Dispersion of the 583 samples in study (map modified from: Siebe et al., 2005; Siebe et al., 2004). The Chichinautzin Volcanic Field (CVF) is shown (shaded polygon) over the digital elevation model (DEM) from INEGI (2011). The big pale solid triangles represent the three well known stratovolcanoes and their associated samples (small solid black triangle). The small solid black circles represent the samples from the monogenetic cones of CVF.*
