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Cretaceous planktonic foraminifers were recovered from Sites 865, 866, and 869 during Ocean Drilling Program (ODP) Leg 143 in the western central Pacific Ocean Basin. Rare planktonic foraminifers from the shallow-water platform limestone at Site 865 on Allison Guyot and Site 866 on Resolution Guyot range from possible Aptian to Albian in age in agreement with ages provided by benthic foraminifers. The oldest overlying Cretaceous pelagic sediment is early to middle Turonian in age and was recovered from a cavity in the platform limestone at Site 865. Manganese-encrusted pebbles at the top of the Cretaceous pelagic cap contain rare, early Maastrichtian planktonic foraminifers. Possible emergence and/or drowning of the edifice at Allison Guyot, and presumably also at Resolution Guyot, took place during or shortly after the late Albian and prior to deposition of the Turonian sediments. At Site 869 on the archipelagic apron in the Marshall Islands, planktonic foraminifers date a sequence of volcaniclastic deposits as late Cenomanian to Maastrichtian in age. The sequence contains major pulses of turbiditic sedimentation in the Cenomanian and Campanian and smaller pulses in the Turonian, Coniacian, and Maastrichtian. The record of sedimentation from Leg 143 compared to that from selected Deep Sea Drilling Project (DSDP) sites in the central Pacific Ocean Basin shows a similar pattern of pelagic sedimentation and hiatuses. Further, the pattern is similar for sites from topographic highs and deep basins. Pelagic sediments are preserved in the Turonian, Coniacian, upper Santonian to lower Campanian, and upper Campanian to middle Maastrichtian sequences. Hiatuses occur in the lower-to-middle Cenomanian, Turonian, lower Santonian, lower-to-middle Campanian, and upper Maastrichtian sections. The transition from Albian limestone to younger chalk at pelagic sites in the Mid-Pacific Mountains and southern Hess Rise takes place in the uppermost Albian analogous to that of the platform carbonate rocks where it also is associated with a hiatus. Correlation of this transition to similar events in the Tethys and Atlantic Ocean indicates that the demise of carbonate platform sedimentation in the western Pacific is related to a change in sea level in the late Albian Rotalipora appenninica Zone; either a brief, eustatic regressive-transgressive cycle or the initiation of platform drowning. The regional hiatuses are ascribed to times of intensified ocean currents. In the mid-Cretaceous the intensified currents are linked to the production of warm, saline bottom-water during sea-level highstands. Increased upwelling and the rise of the calcite compensation depth during these times produced variations in dissolution intensity at intermediate water-depths and hiatuses in pelagic sedimentation. Pelagic buildups during the intervening quiescent intervals supplied the material that was later redeposited in the basins by mass wasting or subsequent mechanical erosion. The variations in dissolution intensity are likely linked to climatic oscillations. Thus, hiatuses represent warmer periods, whereas, pelagic accumulation correlates with cooler periods. The Late Cretaceous climatic oscillations apparently represent an extension of climate cycles begun in the mid-Cretaceous "greenhouse" state.

Cretaceous Planktonic Foraminifers from Sites 865, 866, and 869: A Synthesis of Cretaceous Pelagic Sedimentation in the Central Pacific Ocean Basin