Figure F11. Composite digital images of cores taken across the E/O boundary using the shipboard GEOTEK digital imaging system. At Site 1218 (shallowest crust 42-Ma), it is clear that the Eocene-Oligocene carbonate transition occurs as a two-step shift. At other sites, in deep water, the transition is more abrupt. Dashed line = base of lithologic transition.

Figure F11. Composite digital images of cores taken across the E/O boundary using the shipboard GEOTEK digital imaging system. At Site 1218 (shallowest crust 42-Ma), it is clear that the Eocene-Oligocene carbonate transition occurs as a two-step shift. At other sites, in deep water, the transition is more abrupt. Dashed line = base of lithologic transition.