Cretaceous Calcareous Plankton Biostratigraphy of Sites 872 through 879

This paper documents the distribution of calcareous nannofossils and planktonic foraminifers in Cretaceous sequences recovered at Sites 872 through 879 drilled on guyots in the central and western Pacific Ocean during Leg 144. Calcareous plankton biostratigraphy allows us to obtain important biostratigraphic age constraints for the onset, development, and demise of shallow-water sedimentation on these guyots. Site 872 on Lo-En Guyot is the only site at which shallow-water limestones were not recovered during Leg 144. Here, the oldest sediment consists of pelagic limestone infilling fractures within the volcanic substrate. Calcareous plankton biostratigraphy constrains the age of these sediments to Coniacian to earliest Santonian (Dicarinella concavata planktonic foraminifer zone; CC14-CC15 nannofossil zones). On Wodejebato Guyot (Sites 873 through 877), initiation of carbonate platform sedimentation occurred in the late Campanian (CC22 nannofossil Zone), continued during the late Campanian and Maastrichtian, and ended during the late, possibly latest, Maastrichtian. On MIT Guyot (Site 878), calcareous plankton biostratigraphy indicates that the initiation of carbonate platform sedimentation occurred in the earliest Aptian (lower part of the Chiastozygus litterarius nannofossil zone before the nannoconid crisis ). After a phreato-magmatic eruption that deposited a polymictic breccia, carbonate sedimentation resumed in the middle late Aptian (Nannoconus truittii Acme, Globigerinelloides algerianus to Hedbergella trocoidea planktonic foraminifer zones). Shallow-water deposition ended during the late Albian after the Biticinella breggiensis Zone. Carbonate platform sedimentation at Site 879 on Takuyo-Daisan Guyot began during the middle late Aptian (N. truittii Acme, G. algerianus to H. trocoidea planktonic foraminifer zones) and ended by late Albian time (Rotalipora ticinensis planktonic foraminifer zone). Shallow-water limestone at Site 879 correlates with the upper carbonate platform sequence recovered at Site 878, but its thickness is only half that of the coeval sequence deposited on MIT Guyot, suggesting the presence of hiatuses