(Table 1) Carbohydrates in different sediment types of the Central Pacific

Total contents of carbohydrates were determined in samples of natural sediments of various genetic types. Analyses were made on board. Deep-sea pelagic sediments (red clays of various types including zeolite clays, and also radiolarian and carbonate oozes) were the main types of sediments studied. Contents of carbohydrates in pelagic oozes of the Central Pacific ranged from 214 to 1605 ppm, averaging 602 ppm of air-dried sediment. Organic matter of the group studied is a diagenetically stable complex, with polysaccharides apparently predominating.

Sample information and classification of lower Miocene gravity-flow types of sediment core CRP-1 (Table 1)

Nineteen samples of the Cape Roberts-1 drillcore were taken from Miocene- age deposits, from 90.25 - 146.50 metres below seafloor (mbsf) for thin section and laser grain-size analysis. Using the grain-size distribution, detailed core logging, X-radiography and thin-section analysis of microstructures, coupled with a statistical grouping of the grain-size data, three main styles of gravity-flow sedimentation were revealed. Thin (centimetre-scale) muddy debris-flow deposits are the most common and are possibly tirggered by debris rain-out from sea-ice These deposits are characterised by very poorly sorted, faintly laminated muddy sandstones with coarse granules toward their base. Contacts are gradational to sharp. Variations on this style of mass-wasting deposit are rhythmically stacked sequences of pebbly-coarse sandstones representing successive thin debris-flow events. These suggest very high sedimentation rates on an unstable slope in a shallow-water proximal glacimarine environment. Sandy-silty turbidites appear more common in the lower sections of the core, below approximately 141.00 mbsf, although they occur occasionally with the debris flow deposits The turbidites are characterised by inversely to normally graded, well-laminated siltstones with occasional lonestones, and represent a more distal shallow-water glacimarine environment.