(Table 3) Grain size composition of Holocene deposits from the Kara Sea

A new generalized schematic map of distribution of recent sediments within Eurasian Arctic shelves is considered. The sediments have accumulated as a result of interaction of various factors and processes specific to high latitudes. They include input of terrigenous material by modern glaciers, ice transport, thermal abrasion, sedimentation controlled by many years of ice cover, and others. Characteristic regularity is marked over Arctic shelves: in seas with heavier ice cover, the most fine-grained deposits are distributed, they contain minimum amount of coarse-grained ice rafted debris; in seas with lighter ice cover mosaic distribution of various types of sediments is observed. Composition of surface sediments from the Arctic shelves corresponds to a relatively cool stage of the modern interglacial period. In the 21-st century a new warming is expected.

(Table 1) Details on the Uranium/Thorium age determinations carried out on core GeoB11569-2

Cold-water corals are widely distributed along the Atlantic continental margin with varying growth patterns in relation to their specific environment. Here, we investigate the long-term development of cold-water corals that once thrived on a low-latitude (17°40'N) cold-water coral mound in the Banda Mound Province off Mauritania during the last glacial-interglacial cycle. U/Th dates obtained from 20 specimens of the cold-water coral Lophelia pertusa, revealed three distinct periods of coral growth during the last glacial at 65 to 57 kyr BP, 45 to 32 kyr BP and 14 kyr BP, thus comprising the cool periods of Marine Isotopic Stages (MIS) 2-4. These coral growth periods occur during periods of increased productivity in the region, emphasizing that productivity seems to be the major steering factor for coral growth off Mauritania, which is one of the major upwelling regions in the world. This pattern differs from the well studied coral mounds off Ireland, where the current regime predominantly influences the prosperity of the cold-water corals. Moreover, coral growth off Ireland takes place during rather warm interglacial and interstadial periods, whereas off Mauritania coral growth is restricted to glacial and stadial periods. However, the on-mound sedimentation patterns off Mauritania largely resemble the observations reported from the Irish mounds. The bulk of the preserved sediments derives from periods of coral growth, whereas during periods without corals hardly any net sedimentation or mound growth took place.

(Table 1) Oxygen and carbon isotopes for planktonic foraminifers at DSDP Hole 64-480

During the cleaning of the HPC core surfaces from Hole 480 for photography, the material removed was conserved carefully in approximately 10 cm intervals (by K. Kelts); this material was made available to us in the hope that it would be possible to obtain oxygen isotope stratigraphy for the site. The samples were, of course, somewhat variable in size, but the majority were probably between 5 and 10 cm**3. Had this been a normal marine environment, such sample sizes would have contained abundant planktonic foraminifers together with a small number of benthics. However, this is clearly not the case, for many samples contained no foraminifers, whereas others contained more benthics than planktonics. Among the planktonic foraminifers the commonest species are Globigerina bulloides, Neogloboquadrina dutertrei, and N. pachyderma. A few samples contain a more normal fauna with Globigerinoides spp. and occasional Globorotalia spp. Sample 480-3-3, 20-30 cm contained Globigerina rubescens, isolated specimens of which were noted in a few other samples in Cores 3,4, and 5. This is a particularly solution-sensitive species; in the open Pacific it is only found widely distributed at horizons of exceptionally low carbonate dissolution, such as. the last glacial-to-interglacial transition.

(Table 1) Types of giant magnetofossils in ODP holes

Magnetotactic bacteria biomineralize magnetic minerals with precisely controlled size, morphology, and stoichiometry. These cosmopolitan bacteria are widely observed in aquatic environments. If preserved after burial, the inorganic remains of magnetotactic bacteria act as magnetofossils that record ancient geomagnetic field variations. They also have potential to provide paleoenvironmental information. In contrast to conventional magnetofossils, giant magnetofossils (most likely produced by eukaryotic organisms) have only been reported once before from Paleocene-Eocene Thermal Maximum (PETM; 55.8 Ma) sediments on the New Jersey coastal plain. Here, using transmission electron microscopic observations, we present evidence for abundant giant magnetofossils, including previously reported elongated prisms and spindles, and new giant bullet-shaped magnetite crystals, in the Southern Ocean near Antarctica, not only during the PETM, but also shortly before and after the PETM. Moreover, we have discovered giant bullet-shaped magnetite crystals from the equatorial Indian Ocean during the Mid-Eocene Climatic Optimum (~40 Ma). Our results indicate a more widespread geographic, environmental, and temporal distribution of giant magnetofossils in the geological record with a link to "hyperthermal" events. Enhanced global weathering during hyperthermals, and expanded suboxic diagenetic environments, probably provided more bioavailable iron that enabled biomineralization of giant magnetofossils. Our micromagnetic modelling indicates the presence of magnetic multi-domain (i.e., not ideal for navigation) and single domain (i.e., ideal for navigation) structures in the giant magnetite particles depending on their size, morphology and spatial arrangement. Different giant magnetite crystal morphologies appear to have had different biological functions, including magnetotaxis and other non-navigational purposes. Our observations suggest that hyperthermals provided ideal conditions for giant magnetofossils, and that these organisms were globally distributed. Much more work is needed to understand the interplay between magnetofossil morphology, climate, nutrient availability, and environmental variability.

(Table 2) Copepod carbon production in the upper 50 m in Godthabsfjord and Fyllas Banke, West Greenland

This study describes differences in plankton community structure and in chemical and physical gradients between the offshore West Greenland Current system and inland regions close to the Greenland Ice Sheet during the post-bloom in Godthabsfjorden (64° N, 51° W). The offshore region had pronounced vertical mixing, with centric diatoms and Phaeocystis spp. dominating the phytoplankton, chlorophyll (chl) a (0.3 to 3.9 µg/l) was evenly distributed and nutrients were depleted in the upper 50 m. Ciliates and heterotrophic dinoflagellates constituted equal parts of the protozooplankton biomass. Copepod biomass was dominated by Calanus spp. Primary production, copepod production and the vertical flux were high offshore. The water column was stratified in the fjord, causing chl a to be concentrated in a thin sub-surface layer. Nutrients were depleted above the pycnocline, and Thalassiosira spp. dominated the phytoplankton assemblage close to the ice sheet. Dinoflagellates dominated the protozooplankton biomass, whereas copepod biomass was low and was dominated by Pseudocalanus spp. and Metridia longa. Primary production was low in the outer part of the fjord but considerably higher in the inner parts of the fjord. Copepod production was exceeded by protozooplankton production in the fjord. The results of both physical/chemical factors and biological parameters suggest separation of offshore and fjord systems.

(Table II, page 668-669) Distribution of elements between minerals soluble in 1M Hydroxylamine hydrochloride (Reducible); in 1m HCL (Acid-soluble) and in the insoluble residue of manganese nodules

Attempts to classify pelagic sediments have been based either on appearance and composition, or on the ultimate origin of the components. In particular it appears feasible to distinguish minerals which crystallized in sea-water from those which formed in magmas, in hydrothermal solution, or by weathering under acidic conditions. It is the case of iron and manganese oxide mineral aggregates which constitute one of the major types of rock encountered on the ocean floor; according to Menard (unpublished) about 10% of the pelagic area of the Pacific is covered by such nodules. The nodules consist of intimately intergrown crystallites of different minerals among those identified, besides detrital minerals and organic matter, are opal, goethite, rutile, anatase, barite, nontronite, and at least three manganese oxide minerals of major importance. Arrhenius and Korkisch (1959) have attempted to separate from each other the different minerals constituting the nodules, in order to establish the details of their structure and the localization of the heavy metal ions. The results demonstrate (Table II) that copper and nickel are concentrated in the manganese oxide phases concentrated in the reducible fraction. Cobalt, part of the nickel and most of the chromium are distributed between these and the acid-soluble group of the non-manganese minerals, dominated by goethite and disordered FeOOH.

(Table 2) Contents of U, P2O5, CO2, and TOC in phosphorites from Pacific seamounts

Uranium content of in phosphorites from Pacific seamounts does not exceed 10ppm; it is significantly lower than in phosphorites from submarine continental margins and deposits on land. Phosphate is not the main carrier of uranium, which is inhomogeneously distributed in ferromanganese hydroxide-, phosphate-, silicate- and carbonate materials. Uranium associated with phosphate is not isomorphic admixture. Uranium occurs in rocks in fine particles of unknown composition. Ultramicroscopic inclusions of U(IV) oxides have been also found.