Clay mineralogical assemblages, Sm-Nd concentrations, Sm and Nd isotopic ratios and oxygen isotope ratios, OIS number and the age model of ODP Site 105-646

We present 40 Sm-Nd isotope measurements of the clay-size (<2 µm) fractions of sediments from the Southern Greenland rise (ODP-646) that span the last 365 kyr. These data track changes in the relative supply of fine particles carried into the deep Labrador Sea by the Western Boundary Under Current (WBUC) back to the fourth glacial-interglacial cycles. Earlier studies revealed three general sources of particles to the core site: (i) Precambrian crustal material from Canada, Greenland, and/or Scandinavia (North American Shield - NAS), (ii) Palaeozoic or younger crustal material from East Greenland, NW Europe, and/or western Scandinavia (Young Crust - YC) and (iii) volcanic material from Iceland and the Mid-Atlantic Ridge (MAR). Clay-size fractions from glacial sediments have the lowest Nd isotopic ratios. Supplies of young crustal particles were similar during glacial oxygen isotope stages (OIS) 2, 6, and 10. In contrast the mean volcanic contributions decreased relative to old craton material from OIS 10 to OIS 6 and then from OIS 6 to OIS 2. The glacial OIS 8 interval displays a mean Sm/Nd ratio similar to those of interglacials OIS 1, 5, and 9. Compared with other interglacials, OIS 7 was marked by a higher YC contribution but a similar ~30% MAR supply. The overall NAS contribution dropped by a factor of 2 during each glacial/interglacial transition, with the MAR contribution broadly replacing it during interglacials. To decipher between higher supplies and/or dilution, particle fluxes from each end member were estimated. Glacial NAS fluxes were systematically higher than interglacial fluxes. During the time interval examined, fine particle supplies to the Labrador Sea were strongly controlled by proximal ice-margin erosion and thus echoed the glacial stage intensity. In contrast, the WBUC-carried MAR supplies from the eastern basins did not change significantly throughout the last 365 kyr, except for a marked increase in surface-sediments that suggests unique modern conditions. Distal WBUC-controlled inputs from the Northern and NE North Atlantic seem to have been less variable than proximal supplies linked with glacial erosion rate.

Grain size and magnetic fabric analyses

The combined use of grain size and magnetic fabric analyses provides the ability to discriminate among depositional environments in deep-sea terrigenous sediments. We analyzed samples from three different depositional settings: turbidites, pelagic or hemipelagic interlayers, and sediment drifts. Results indicate that sediment samples from these different environments can be distinguished from each other on the basis of their median grain size, sorting, as well as the intensity and shape of magnetic fabric as determined from an examination of the anisotropy of magnetic susceptibility. We use these discriminators to interpret downcore samples from the Bermuda Rise sediment drift. We find that the finer grains of the Bermuda Rise (relative to the Blake Outer Ridge) do not result from lower depositional energy (current speed) and so may reflect a difference in the nature of sediment being delivered to the site (i.e., distance from source) between the two locations.

Percentage of cultured cell-populations that stained positively and/or negatively for apoptotic markers cleaved caspase-3 and cleaved PARP, following DNA damage treatments induced by doxorubicin and TNF-alpha co-treatments

The present dataset contains the source data for Figure 2B of Tentner et al. (2012). The data shows the percentage of cultured cell-populations that stained positively and/or negatively for apoptotic markers cleaved caspase-3 and cleaved PARP, following DNA damage treatments induced by various doses of doxorubicin (0, 2 and 10 µmole/L) in the presence (100 ng/mL) or absence (0 ng/mL) of TNF-alpha co-treatment. For the six treatment conditions investigated, cell counts were made by flow cytometry at times 6, 12, 24, and 48 h following treatment; CULTURE DETAILS: U2OS cells were obtained from ATCC were maintained at 21% oxygen and 5% CO2 in Dulbecco's modified Eagle medium supplemented with 10% fetal bovine serum, penicillin, streptomycin, 2mM L-glutamine, and used within 15-20 passages. The first thymidine block was released by washing the plates three times with PBS, and incubating them in fresh thymidine-free media for 12 h. A second thymidine block was then performed by re-addition of thymidine to 2.5 mM followed by incubation for an additional 18 h. Media was aspirated, plates were washed 3 with PBS, and replaced with fresh media in the presence or absence of 10 mM aphidicolin; ANALYSIS DETAILS: See supplementary journal publication; RESULT: The authors of the supplementary journal publication conclude that TNF enhances dose-dependent cell death following doxorubicin-induced DNA damage with minimal affect on dose-dependent cell-cycle arrest.

Chemical and isotopic composition of seawater and waters from thermal spring sites of the Yankicha Island and Kraternaya Bay

A study of chemical and isotopic composition of coastal thermal springs and waters of the Kraternaya Bay, Yankicha Island, revealed that the total mineralization and concentrations of d18O and d2H decrease from the thermal spring site I to V. These waters are of marine origin with various proportions of local meteoric water. Thermal waters of the site VI have considerably altered chemical and isotopic composition due to high temperatures of surrounding rocks. Base temperatures calculated for this area were 130-200°C. Coastal thermal springs affect isotopic composition of water throughout the bay.

(Table 1) I, Br, B, d11B and Mn concentrations in ODP Site 131-808

This study of the interstitial water concentration-depth distributions of iodide, bromide, boron, d11B, and dissolved organic carbon, as represented by absorbance at 325 nm (yellow substance: YS) and laser-induced fluorescence (LIF), is a follow-up of the extensive shipboard program of interstitial water analysis during ODP Leg 131. Most of the components studied are associated with processes involving the diagenesis of organic matter in these sediments. Three zones of the sediment column are discussed separately because of the different processes involved in causing concentration changes: 1. The upper few hundreds of meters: In this zone, characterized by very high sedimentation rates (>1200 m/m.y.), interstitial waters show very sharp increases in alkalinity, ammonia, iodide, bromide, YS, and LIF, mainly as a result of the diagenesis of organic carbon; 2. Whereas below 200 mbsf concentration gradients all show a decreasing trend, the zone at ~ 365 mbsf is characterized by concentration reversals, mainly due to the recent emplacement of deeper sediments above this depth as a result of thrust-faulting; 3. The décollement zone (945-964 mbsf) is characterized by concentration anomalies in various constituents (bromide, boron, d11B, manganese, LIF). These data are interpreted as resulting from an advective input of fluids along the zone of décollement as recent as ~ 200 ka. Possibly periodic inputs of anomalous fluids still seem to occur along this décollement zone.

Raw and normalized X-ray fluorescence (XRF) scannings of IODP Expedition 321, Site U1338

We used X-ray fluorescence (XRF) scanning on Site U1338 sediments from Integrated Ocean Drilling Program Expedition 321 to measure sediment geochemical compositions at 2.5 cm resolution for the 450 m of the Site U1338 spliced sediment column. This spatial resolution is equivalent to ~2 k.y. age sampling in the 0-5 Ma section and ~1 k.y. resolution from 5 to 17 Ma. Here we report the data and describe data acquisition conditions to measure Al, Si, K, Ca, Ti, Fe, Mn, and Ba in the solid phase. We also describe a method to convert the data from volume-based raw XRF scan data to a normalized mass measurement ready for calibration by other geochemical methods. Both the raw and normalized data are reported along the Site U1338 splice.

Pliocene-Pleistocene oxygen isotope record DSDP Site 586, Ontong Java Plateau, Pacific Ocean i

Oceanographic changes in the western equatorial Pacific during the past 6 Ma are inferred from oxygen isotopic analyses of planktic and benthic foraminifera from Ontong Java Plateau (DSDP Site 586). The taxa are Globigerinoides sacculifer, Pulleniatina, Cibicidoides wuellerstorfi, and Oridorsalis umbonatus. Cooling and ice buildup are indicated by an 18O enrichment of 0.3 per mil in the planktic species near 3.4 Ma. This shift apparently is compensated in the benthic data by a warming of the deep waters by between 1° and 2° C. We suggest that the dominant source of upper deep water supply to the Pacific changed from Antarctic to North Atlantic at that time, the North Atlantic-derived water being warmer. Near 2.8 Ma (approximately) the planktic foraminifera again record an enrichment in 18O (Delta delta18O=0.25 per mil). We suggest ice buildup in the northern hemisphere as the cause, because of subsequent sharp increase in fluctuations of the delta18O signal, that is, instability. The enrichment is magnified in the benthic foraminifera (Delta delta18O = 0.5 per mil) by a cooling of the deep water by 1.5° at the time, presumably signalling a glacial-type reduction of North Atlantic Deep Water (NADW) production. Episodic divergence between the signals of G. sacculifer and Pulleniatina in the Pleistocene apparently reflects periods of increased upwelling in the western equatorial Pacific. The amplitude of ice volume fluctuations cannot be reconstructed from delta18O data alone, unless there are constraints on temperature variations. The increase in amplitude of fluctuation of the benthic and planktic signals during the Pleistocene may be attributed either to an increase in maximum ice volume, or to an increase in the fractionation of continental ice, or a combination of both causes.