Page 175 - Caldera Volcanism Analysis, Modelling and Response
P. 175
150 Gerardo J. Aguirre-Dı ´az et al.
Figure 3 Representative schematic sections of the main stratigraphic units and lithologies
of the SMO as two separate groups, one for the central-northern sectors and another for the
southern sector. Each locality shows a particular stratigraphy, but it can be noticed that in
general the thickest units correspond to the mid-Tertiary ignimbrite package that mostly
occurred between 38 and 23 Ma.This has an average thickness of 1,000 m, which has been
de¢ned as the Ignimbrite Flare-up event (Aguirre-D|¤az and Labarthe-Herna Ł ndez, 2003).
(Modi¢ed from Aguirre-D|¤az and McDowell,1991).
