(Table 1) Concentrations of CaCO3 and organic carbon, organic matter atomic C/N ratios and delta13C values of sediment samples from Site DSDP 594

CaCO3 and total organic carbon concentrations, organic matter C/N and carbon isotope ratios, and sediment accumulation rates in late Quaternary sediments from DSDP Site 594 provide information about glacial-interglacial variations in the delivery of organic matter to the Chatham Rise offshore of southeastern New Zealand. Low C/N ratios and nearly constant organic delta13C values of ?23? indicate that marine production dominates organic matter supply in both glacial and interglacial times during oxygen isotope stages 1 through 6 (0-140 ka) and 17 through 19 (660-790 ka). Increased organic carbon mass accumulation rates in isotope stages 2, 4, 6, and 18 record enhanced marine productivity during glacial maxima. Excursions of organic delta13C values to ca. ?29? in portions of isotope stage 2 suggest that the local concentration of dissolved CO2 was occasionally elevated during the last glacial maximum, probably as a result of short periods of lowered sea-surface temperature. Dilution of carbonates by clastic continental sediment generally increases at this location during glacial maxima, but enhanced delivery of land-derived organic matter does not accompany the increased accumulation of clastic sediments.

Organic d13C values, kerogen atomic C/N ratios and relative weights of some kerogen pyrolysis products of ODP Hole 112-682A (Table 1)

Carbon isotopic composition of predominantly marine kerogen in latest Oligocene mudstones of the Peru Margin ODP 682A Hole shows an about 3.5? increase with decreasing age. Py-GC and elemental (C=N ratio) analysis of the kerogen plus sulphur isotopic study together with earlier knowledge on geological setting and organic geochemistry results in a better understanding of depositionary environment and allows to separation of the influence of concentration of water dissolved carbon dioxide (ce) on kerogen delta13C from that of other factors (bacterial degradation, sea surface temperature, DIC delta13C, productivity, and admixture of land plant OM). Based on this analysis, the major part of the kerogen shift is considered as a result of the latest Oligocene decrease of marine photosynthetic carbon isotopic fractionation in the Peru Margin photic zone, which in turn possibly reflects a simultaneous drop in atmospheric CO2 level. Uncertainties in the evaluation of the factors affecting the marine photosynthetic carbon isotopic fractionation and the extent of ocean-atmosphere disequilibrium do not permit calculation of the decrease of the atmospheric CO2.

Observation of manganese deposits made during the 1936 transect of C/S Lord Kelvin through the Northern Atlantic Ocean

In May and June 1936 Dr. C. S. Piggot of the Geophysical Laboratory, Carnegie Institution of Washington, took a series of 11 deep-sea cores in the North Atlantic Ocean between the Newfoundland banks and the banks off the Irish coast. These cores were taken from the Western Union Telegraph Co.'s cable ship Lord Kelvin with the explosive type of sounding device which Dr. Piggot designed. All but two of these cores (Nos. 8 and 11) are more than 2.43 meters (8 feet) long, and all contain ample material for study. Of the two short cores, No. 8 was taken from the top of the Faraday Hills, as that part of the mid-Atlantic ridge is known, where the material is closely packed and more sandy and consequently more resistant; No. 11 came from a locality where the apparatus apparently landed on volcanic rock that may be part of a submarine lava flow.

AMS C-14 ages of coretops collected on RRS Charles Darwin cruise CD159, July 2004, N. Atlantic, for the NERC RAPID programme

Material and data were collected at 41 sites in the subpolar North Atlantic Ocean between Scotland and Newfoundland, during the RRS CharlesDarwin CD159 cruise in July 2004 (McCave, 2005). Sites were selected to reflect the major inputs of water that becomes the North Atlantic Deep Water (NADW); the Iceland-Scotland Overflow Water (ISOW), the Denmark Strait Overflow Water (DSOW) and the Labrador Sea Water (LSW). Areas cored were the south Iceland Rise, SE Greenland slope/rise and Eirik Drift, and the Labrador margin. A total of 29 box cores, 19 piston cores, 6 kasten cores, 9 short gravity cores and 20 CTD casts as well as 28 surface water samples were collected during the cruise. Here we present sediment core-top sample ages. The cores were sampled at 1 or 0.5 cm intervals and we used the top 1 or 2 cm, depending on availability of foraminifera in the samples. Sediment samples were disaggregated on an end-over-end wheel, wet sieved at >63 um, and dry sieved to 63-150 and >150 um. Accelerator Mass Spectrometer (AMS) radiocarbon dating was done for each core top based on between 900-1600 monospecific planktonic foraminifera (Globigerina bulloides or Neogloboquadrina pachyderma (sinistral)). All dates were of modern or late Holocene age except site RAPID-08-5B (9806 ± 38 uncorrected 14C years BP) and site RAPID-14-10B (11543 ± 40 uncorrected 14C years BP). The >150 um fraction was split until approximately 300 foraminifera remained and counted for number of lithic grains, benthic foraminifera, planktonic foraminifera and foraminifera fragments. In all but the shallowest sample (Greenland rise, 761m water depth) benthic foraminifera constituted less than 2% of the total >150 um fraction of the sample.