Figure F2. Compilation of 40Ar/39Ar, K/Ar, and U-Pb zircon dating results for Eocene igneous rocks from the IBM fore arc, modified after Ishizuka et al. (2011). 40Ar/39Ar ages are calculated using 27.5 Ma for sanidine from Fish Canyon Tuff (FC3). Data sources other than Ishizuka et al. (2011): a = Cosca et al. (1998), b = Reagan et al. (2008), c = Kaneoka et al. (1970), d = Ishizuka et al. (2006), e = Ishizuka et al. (2011a), f = Reagan et al. (2013). 40Ar/39Ar age of Cosca et al. (1998) is calculated using an age of 520.4 Ma for MMHB-1. 40Ar/39Ar age of Reagan et al. (2008) is calculated using an age of 27.84 Ma for FC-2 Fish Canyon Tuff. Expedition 352 will focus on the detailed stratigraphy of the 7 m.y. period between these events. DSDP = Deep Sea Drilling Project.