, et al., 1993. Proc. ODP, Init. Repts., 143: College Station, TX (Ocean Drilling Program)." Shipboard Scientific Party is as given in list of participants preceding the contents.Principal results: Site 869 (proposed Site Syl-3) is situated 45 nmi (83 km) southwest of the atoll-guyot pair, Pikinni Atoll (formerly Bikini) and Wodejebato Guyot (formerly Sylvania). Drilling at this location was planned to provide a basinal reference section for comparison to Leg 144 drill holes on the summit of Wodejebato and prior drilling on Pikinni. Site-survey data suggested that a thick, layered succession of sediments exists at the site that consists mainly of turbidites. Volcanic basement is not obvious in the site-survey seismic lines, so drilling was not expected to encounter basement basalt. Approximately 850 m of penetration was planned, and the expectation was to bottom in Cretaceous volcaniclastics produced by constructional volcanism on either or both Wodejebato and Pikinni. The location of Site 869, at 1 l°00.09'N, 164°45.02'E, was chosen on the seafloor adjacent to both Pikinni and Wodejebato, close enough to receive sediments shed mainly by these edifices, but far enough away so that both would contribute. It was assumed that sedimentation at an adjacent basinal hole would parallel and complement that on the atollguyot pair. For example, erosional hiatuses on the summit might be expected to produce sediments on the archipelagic apron, thus filling "missing chapters" in the geologic history provided by summit holes. Drilling at Site 869 was undertaken to address the following primary goals:1. Determining the history of volcanism on Pikinni/Wodejebato; 2. Developing a model of Cretaceous, mid-ocean guyot/atoll carbonate platform formation and evolution for the Marshall Islands; 3. Comparison of the timing and effects of fluctuations in relative sea level among Pacific guyots and relation to worldwide sea-level curves; and 4. Deciphering the cause(s) for the drowning(s) of some Marshall Islands guyots (such as Wodejebato) vs. the existence of Cenozoic reefs on nearby atolls (such as Pikinni).Two holes were drilled at Site 869, an APC/XCB hole (Hole 869A), and an RCB hole (Hole 869B), the latter located about 93 m north of the former. The operational plan was to use the APC/XCB combination to obtain relatively undisturbed cores from the upper 300 to 400 m of the sedimentary column. In analogy to Site 462, hard chert layers were expected to frustrate drilling at about 300 to 400 mbsf, and a round-trip was planned to change to an RCB bit and begin a second hole. Chert and porcellanite were encountered at much shallower depths than expected, and Hole 869A was terminated at a depth of only 166.5 mbsf. Hole 869B was washed to 140.0 mbsf and cored continuously to a total depth of 796.2 mbsf.Core recovery in Hole 869A, drilled with the APC/XCB combination, was mostly excellent, with the average being over 100% for the APC cores and 77.6% overall. In Hole 869B, recovery was variable (see "Operations" section, this chapter). ...