(Table 1) Some structural characteristics of communities and detritus flux through the lower boundary of a given water column in different regions of the Kara Sea

Vertical fluxes of autochtonous detritus at different levels were estimated using the algorithm of structure-function analysis. The calculations are based on pelagic ecosystem parameters in the Kara Sea observed in September 1993 (temperature, primary production, biomass of phytoplankton, bacteria, protozoa, and zooplankton, trophic and size composition, etc.). At eight stations in different parts of the sea where sedimentation traps were set, the range of calculated fluxes of autochtonous detritus through the lower boundary of the water column was 13-90 mgC/m**2/day. The flux was much higher in the estuary of the Yenisey River (55-90 mgC/m**2/day) than in the northeastern regions (I8-50 mgC/m**2/day) and, especially, in the relatively deep southwestern part of the sea (13-35 mgC/m**2/day). The calculated fluxes of autochtonous detritus in shallow water regions (where conditions are variable and poorly known hydrologically and where outflow of allochtonous detritus is substantial) cannot be compared to data from sedimentation traps.

Sand geochemistry on sediment core CRP-3 from the Ross Sea, Antarctica

A total of 167 samples distubuted throughout the CRP-3 drillhole from 5.77 to 787.68 mbsf and representing fine to coarse sandstones have been analysed by X-ray fluorescence spectrometry (XRF) Bulk sample geochemistry (major and trace elements) indicates a dominant provenance of detritus from the Ferrar Supergroup in the uppermost 200 mbsf of the core. A markedly increased contribution from the Beacon sandstones is recognized below 200 mbsf and down to 600 mbsf. In the lower part of CRP-3, down to 787.68 mbsf, geochemical evidence for influxes of Ferrar materials is again recorded. On the basis of preliminary magnetostratigraphic data reported for the lower 447 mbsf of the drillhole, we tentatively evaluated the main periodicities modulating the geochemical records. Our results identify a possible influence of the precession, obliquity and long-eccentricity astronomical components (21, 41, and 400 ky frequency bands) on the deposition mechanisms of the studied glaciomarine sediments.