Figure 8. A comparison of the Caribbean record of explosive volcanism (tephra accumulation rate at ODP Site 999), compared with global cooling events (positive 18O excursions) through the last 50 m.y. of the Cenozoic. Also shown are periods of major ignimbrite volcanism in northern Mexico and the southwestern United States (McDowell and Mauger, 1994). Isotopic data from multiple sources: Mix et al. (1995; Pliocene-Pleistocene), Miller et al. (1996, 1998; Miocene), Pekar and Miller (1996; Oligocene), and Zachos (in Baker and McNutt, 1998; Eocene). Labeled oxygen isotope events of the Oligocene and Miocene are after Miller et al. (1996).