Reoccupied Leg 201 drill sites are located in different contrasting geological settings (Fig. F1). Sites 1225/851 and 1226/846 are located in the eastern equatorial Pacific. They show an open-ocean stratigraphic sequence dominated by nannofossil and diatom ooze of the high-productivity south equatorial boundary current (Mayer, Pisias, Janecek, et al., 1992). In contrast, sediments of the Peru margin shelf sites (Sites 1227, 1228, and 1229) show variable contents of siliciclastic material and low contents of carbonaceous nannoplankton (Suess, von Huene, et al., 1988). Strong coastal upwelling increases productivity at these sites, and most of these sediments are deposited at low oxygen content. Sediments of the Peru Trench (Site 1230) also show upwelling-related sedimentation with mainly diatom ooze and variable siliciclastic content (Suess, von Huene, et al., 1988). At this site, methanogenic activity is enhanced and gas hydrates were found (D'Hondt, Jørgensen, Miller, et al., 2003). Site 1231 is located in the Peru Basin, far away from high organic matter input, showing low productivity with mixed pelagic sedimentation (Yeats, Hart, et al., 1976).