Fig. 50

East-west cross-section of Atlantis Bank through Hole 735B based on the seafloor geology and ODP and IODP drill cores. Subsurface geology at depth including dunite melt transport zone and basal cumulates, and the location of crust-mantle boundary is somewhat arbitrary as the seismic data are not definitive, and we only know that a considerable volume of primitive cumulates must lie below the hole. Heavy black lines show the Moho reflectors (Minshull et al. 1998; Muller et al. 2000; Muller et al. 1997). The gaps are attributed to the geometry of ocean bottom seismometer emplacement and ray tracing. Best guess model for Moho and crust-mantle boundary are shown—but only drilling will tell. Lithologic units in the gabbro massif are identified by color in the inset dive profiles