(Table 1) Microplankton biomass determined from ATP and by microscopy

Simultaneous determinations of the microplankton biomass by direct microscopy and by measuring concentration of adenosine triphosphate (ATP) in samples from different depths of the Eastern Pacific revealed considerable differences between values obtained. With the exception of 3 of 62 determinations, the biomass determined from ATP exceeded that measured by microscopy; the latter averaged about 10% of the former for the region as a whole. This sharp difference is largely due to underestimation of ultramicroscopic cells by direct microscopy and to substantial variations in the factor used to convert ATP concentrations to cell biomass.

Curie temperatures and cell edges of ODP Leg 120 samples (Table 1)

Basalt samples recovered on Ocean Drilling Program Leg 120 from the Kerguelen Plateau were investigated by thermomagnetic analysis, X-ray diffraction, and ore microscopy. The basement samples could be divided into two groups based on Curie temperatures, cell-edge parameters, and optical magnetic mineralogy. Samples from Sites 748 and 750 underwent only low-temperature oxidation and displayed Curie temperatures for the titanomaghemites that ranged from 340° to 395°C. The basalts from Sites 747 and 749 mainly experienced high-temperature oxidation. High-temperature oxidation produced titanium-poor titanomagnetites with ilmenite-exsolution lamellae. Curie temperatures of the deuterically oxidized titanomaghemites varied from 490° to 620°C.

Analysis of the iron oxide assemblages in the ANDRILL AND-1B drill core, Ross Sea, Antarctica

The AND-1B drill core recovered a 13.57 million year Miocene through Pleistocene record from beneath the McMurdo Ice Shelf in Antarctica (77.9°S, 167.1°E). Varying sedimentary facies in the 1285 m core indicate glacial-interglacial cyclicity with the proximity of ice at the site ranging from grounding of ice in 917 m of water to ice free marine conditions. Broader interpretation of climatic conditions of the wider Ross Sea Embayment is deduced from provenance studies. Here we present an analysis of the iron oxide assemblages in the AND-1B core and interpret their variability with respect to wider paleoclimatic conditions. The core is naturally divided into an upper and lower succession by an expanded 170 m thick volcanic interval between 590 and 760 m. Above 590 m the Plio-Pleistocene glacial cycles are diatom rich and below 760 m late Miocene glacial cycles are terrigenous. Electron microscopy and rock magnetic parameters confirm the subdivision with biogenic silica diluting the terrigenous input (fine pseudo-single domain and stable single domain titanomagnetite from the McMurdo Volcanic Group with a variety of textures and compositions) above 590 m. Below 760 m, the Miocene section consists of coarse-grained ilmenite and multidomain magnetite derived from Transantarctic Mountain lithologies. This may reflect ice flow patterns and the absence of McMurdo Volcanic Group volcanic centers or indicate that volcanic centers had not yet grown to a significant size. The combined rock magnetic and electron microscopy signatures of magnetic minerals serve as provenance tracers in both ice proximal and distal sedimentary units, aiding in the study of ice sheet extent and dynamics, and the identification of ice rafted debris sources and dispersal patterns in the Ross Sea sector of Antarctica.

Mineralogy and inorganic geochemistry of sediments at DSDP Leg 65 Holes

During Leg 65, 15 holes were drilled at four sites located on young crust in the mouth of the Gulf of California. Quaternary to upper Pliocene hemipelagic sediments above and interlayered within the young basaltic basement were cored. The influence of hot lava, high temperature gradients, and hydrothermal activity on the mineralogy and geochemistry of the terrigenous sediments near contacts with basalts might therefore be expected. The purpose of the present study was to determine the mineralogy and inorganic geochemistry of these sediments and to analyze the nature and extent of low temperature alteration. To this end we studied the mineralogy and inorganic geochemistry of 75 sediment samples, including those immediately overlying uppermost basalts and those from layers alternating with basalts within the basement. We separated three size fractions - <2 µm (clay), 2-20 µm (intermediate), and >20 µm (coarse) - and applied the following mineralogical determinations: x-ray diffraction (XRD), infrared spectroscopy, transmission and scanning electron microscopy, and optical microscopy (for coarse fractions, using thin sections and smear slides). We calculated the percentages of clay minerals using Biscaye's (1964) method, and used routine wet chemical analyses to determine bulk composition and quantitative spectral analyses for trace elements.

Geochemistry and petrography of organic matter at DSDP Site 93-603

A series of 22 sediment samples of Cretaceous and Cenozoic age from DSDP Holes 603, 603B, and 603C at the continental rise off the northeastern American coast near Cape Hatteras was investigated by organic geochemical methods including organic carbon determination, Rock-Eval pyrolysis, gas chromatography and combined gas chromatography/mass spectrometry of extractable hydrocarbons, and kerogen microscopy. An abundance of terrigenous organic matter, including larger coal particles (almost exclusively consisting of huminite/vitrinite macerals), is the dominant characteristic of the organofacies types at Site 603. Marine organic matter, mostly structurally degraded and in the form of fecal pellets, was preserved in the Valanginian laminated marls and in Cenomanian black claystone turbidites. Long-chain nalkanes reflect the terrigenous imprint in the nonaromatic hydrocarbon fractions, whereas a second maximum at lower carbon numbers in most cases is caused by the presence of more mature recycled organic matter. Abundant isoprenoid and steroid hydrocarbons were found in sediments containing mainly marine organic matter, whereas hopanoids reflect the ubiquitous microbial activity. The organic matter in the Site 603 sediments, in so far as it is not recycled, is thermally immature.

Facies and diagenesis of organic matter in sediments at DSDP Leg 87

A series of upper Pliocene to Pleistocene sediment samples from DSDP Sites 582 and 583 (Nankai Trough, active margin off Japan) were investigated by organic geochemical methods including organic carbon determination, Rock- Eval pyrolysis, gas chromatography of extractable hydrocarbons, and kerogen microscopy. The organic carbon content is fairly uniform and moderately low (0.35 to 0.77%) at both sites, although accompanied by high sedimentation rates. The low organic matter concentrations are the result of the combined effect of several factors: low bioproductivity, oxic depositional environment, and dilution with lithogenic material. Organic petrography revealed a mixture of three maceral types: (1) fresh, green fluorescent alginites of aquatic origin probably transported by turbidites from the shelf edge, (2) gelified huminites and paniculate liptinites derived from the erosion of unconsolidated peat, and (3) highly reflecting inertinites derived from continental erosion. By a combination of organic petrography and Rock-Eval pyrolysis results, the organic matter is characterized as mainly type III kerogen with a slight tendency to a mixed type II-III. During Rock-Eval pyrolysis, a mineral matrix effect on the generated hydrocarbons was observed. The organic matter in all sediments has a low level of maturity (below 0.45% Rm) and has not yet reached the onset of thermal hydrocarbon generation according to several geochemical maturation parameters. This low maturity is in contrast to anomalously high extract yields at both sites and large hydrocarbon proportions in the extracts at Site 583. This contrast may be due to early generation of polar compounds and perhaps redistribution of hydrocarbons caused by subduction tectonics. Carbon isotope data of the interstitial hydrocarbon gases indicate their origin from bacterial degradation of organic matter, although only very few bacterially degraded maceral components were detected.

Lithology, stratigraphy, organic carbon content, extract and liquid chromatography yields, and Rock-Eval pyrolysis at DSDP Holes 75-530A and 75-532

Seventeen sediment samples of Albian-Cenomanian to early Pliocene age from DSDP Hole 530A in the Angola Basin and six sediment samples of early Pliocene to late Pleistocene age from the Walvis Ridge were investigated by organic geochemical methods, including organic carbon determination, Rock-Eval pyrolysis, gas chromatography and combined gas chromatography/mass spectrometry of extractable hydrocarbons, and kerogen microscopy. The organic matter in all samples is strongly influenced by a terrigenous component from the nearby continent. The amount of marine organic matter present usually increases with the total organic carbon content, which reaches an extreme value of more than 10% in a Cenomanian black shale from Hole 530A. At Site 530 the extent of preservation of organic matter in the deep sea sediments is related to mass transport down the continental slope, whereas the high organic carbon contents in the sediments from Site 532 reflect both high bioproductivity in the Benguela upwelling regime and considerable supply of terrigenous organic matter. The maturation level of the organic matter is low in all samples.

Chemistry of secondary minerals from the deep sheeted dike complex of ODP Holes 137-504B and 140-504B

Dolerites sampled from the lower sheeted dikes from Hole 504B during Ocean Drilling Program Legs 137 and 140, between 1562.4 and 2000.4 mbsf, were examined to document the mineralogy, petrography, and mineral parageneses associated with secondary alteration, to constrain the thermal history and composition of hydrothermal fluids. The main methods used were mineral chemical analyses by electron microprobe, X-ray diffraction, and cathodoluminescence microscopy. Temperatures of alteration were estimated on the basis of single and/or coexisting mineral chemistry. Permeability is important in controlling the type and extent of alteration in the studied dike section. At the meter-scale, intervals of weakly altered dolerites containing fresh olivine are interpreted as having experienced restricted exposure to hydrothermal fluids. At the centimeter- or millimeter-scale, alteration patches and extensively altered halos adjacent to veins reflect the permeability related to intergranular primary porosity and cracks. Most of the sheeted dike alteration in this case resulted from non-focused, pervasive fluid-rock interaction. This study confirms and extends the previous model for hydrothermal alteration at Hole 504B: hydrothermal alteration at the ridge axis followed by seawater recharge and off-axis alteration. The major new discoveries, all related to higher temperatures of alteration, are: (1) the presence of hydrothermal plagioclase (An80-95), (2) the presence of deuteric and/or hydrothermal diopside, and (3) the general increasing proportion of amphiboles, and particularly magnesio-hornblende with depth. We propose that the dolerites at Hole 504B were altered in five stages. Stage 1 occurred at high temperatures (less than 500° to 700°C) and involved late-magmatic formation of Na- and Ti-rich diopside, the hydrothermal formation of Na, Ti-poor diopside and the hydrothermal formation of an assemblage of An-rich plagioclase + hornblende. Stage 2 occurred at lower temperatures (250°-320°C) and is characterized by the appearance of actinolite, chlorite, chlorite-smectite, and/or talc (in low permeability zones) and albite. During Stage 3, quartz and epidote precipitated from evolved hydrothermal fluids at temperatures between 310° and 320°C. Anhydrite appeared during Stage 4 and likely precipitated directly from heated seawater. Stage 5 occurred off-axis at low temperatures (250°C) with laumontite and prehnite from evolved fluids.

(Table S1) FMR and rock magnetic parameters for upper Paleocene to lower Eocene strata, Site Ancora

Previous workers identified a magnetically anomalous clay layer deposited on the northern United States Atlantic Coastal Plain during the Paleocene-Eocene thermal maximum (PETM). The finding inspired the highly controversial hypothesis that a cometary impact triggered the PETM. Here we present ferromagnetic resonance (FMR), isothermal and anhysteretic remanent magnetization, first-order reversal curve, and transmission electron microscopy analyses of late Paleocene and early Eocene sediments in drill core from Ancora, New Jersey. A novel paleogeographic analysis applying a recent paleomagnetic pole from the Faeroe Islands indicates that New Jersey during the initial Eocene had a ~6°-9° lower paleolatitude (~27.3° for Ancora) and a more zonal shoreline trace than in conventional reconstructions. Our investigations of the PETM clay from Ancora reveal abundant magnetite nanoparticles bearing signature traits of crystals produced by magnetotactic bacteria. This result, the first identification of ancient biogenic magnetite using FMR, argues that the anomalous magnetic properties of the PETM sediments are not produced by an impact. They instead reflect environmental changes along the eastern margin of North America during the PETM that led to enhanced production and/or preservation of magnetofossils.

(Table S1) Qualitative and semi-quantitative abundance of magnetic particles in Paleocene-Eocene sediments

On the mid-Atlantic Coastal Plain of the United States, Paleocene sands and silts are replaced during the Paleocene-Eocene Thermal Maximum (PETM) by the kaolinite-rich Marlboro Clay. The clay preserves abundant magnetite produced by magnetotactic bacteria and novel, presumptively eukaryotic, iron-biomineralizing microorganisms. Using ferromagnetic resonance spectroscopy and electron microscopy, we map the magnetofossil distribution in the context of stratigraphy and carbon isotope data and identify three magnetic facies in the clay: one characterized by a mix of detrital particles and magnetofossils, a second with a higher magnetofossil-to-detrital ratio, and a third with only transient magnetofossils. The distribution of these facies suggests that suboxic conditions promoting magnetofossil production and preservation occurred throughout inner middle neritic sediments of the Salisbury Embayment but extended only transiently to outer neritic sediments and the flanks of the embayment. Such a distribution is consistent with the development of a system resembling a modern tropical river-dominated shelf.

Carbon chemistry of ODP Leg 105 sites

The quantity and quality of organic carbon of Eocene to Holocene sediments from ODP Sites 645, 646, and 647 were investigated to reconstruct depositional environments. Results were based on organic-carbon and nitrogen determinations, Rock-Eval pyrolysis, and kerogen microscopy. The sediments at Site 645 in Baffin Bay are characterized by relatively high organic-carbon values, most of which range from 0.5% to almost 3%, with maximum values in the middle Miocene. Distinct maxima of organic-carbon accumulation rates occur between 18 and 12.5 Ma and between 3.4 and 0 Ma. At Sites 646 and 647 in the Labrador Sea, organic-carbon contents vary between 0.1% and 0.75%. Cyclic 'Milankovitch-type' changes in organic-carbon deposition imply climate-controlled mechanisms that cause these fluctuations. The composition of organic matter at Site 645 is dominated by terrigenous components throughout the entire sediment sequence. An increased content of marine organic carbon was recorded only in the late-middle Miocene. At Sites 646 and 647, the origin of the organic matter most probably is marine. Oceanic paleoproductivity values were estimated, based on the amount of marine organic carbon. During most of the Neogene time interval at Site 645, productivity was low, i.e., similar or less than that measured in Baffin Bay today. Higher values of up to 150 (200) gC/m**2/y may have occurred only in the Miocene. At Sites 646 and 647, mean paleoproductivity values vary between 90 and 170 gC/m**2/y; i.e., these are also similar to those measured in the Labrador Sea today. Lower values of 40 to 70 gC/m**2/y were estimated for the early Eocene and (middle) Miocene.

Diatom abundances of ODP Hole 177-1093A in the Southern Ocean

Laminated diatom ooze samples collected during ODP Leg 177 were analysed using scanning electron microscope (SEM) and optical microscopy to test their potential as high-resolution records of Polar Front hydrography, surface production, and export. SEM analysis from two intervals, marine isotope stage (MIS) 29 and 12/11, respectively, recovered from 50°S in the Atlantic Ocean (ODP Site 1093, Hole A, sections 13H-4 0-18 cm and 23H-4 0-22 cm), show abundant and well-preserved Thalassiothrix antarctica mats, thought to be indicative of rapid export from the surface and deposition in the sediment. A preliminary analysis of laminae succession points to a possible annual couplet/triplet succession of laminae, and suggests exceptionally high local sedimentation rates of 57 and 80 cm/kyr for MIS 12/11 and 29, respectively. Such high accumulation rates imply that local export from the surface layer and sequestration of biogenic silica and organic matter to the sediments may have been much higher than previously suggested.

PeECE III - Pelagic Ecosystem CO2 Enrichment Study, Raunefjord, Bergen, Norway, 2005

The effects of CO2-induced seawater acidification on plankton communities were also addressed in a series of 3 mesocosm experiments, called the Pelagic Ecosystem CO2 Enrichment (PeECE I-III) studies, which were conducted in the Large-Scale Mesocosm Facilities of the University of Bergen, Norway in 2001, 2003 and 2005, respectively. Each experiment consisted of 9 mesocosms, in which CO2 was manipulated to initial concentrations of 190, 350 and 750 µatm in 2001 and 2003, and 350, 700 and 1050 µatm in 2005. The present dataset concerns PeECE III.

(Table 1, page 661) Average composition of fossil nodules from three localities studied in the Transdanubian Central Mountains of Hungary

Fossil manganese nodules and encrustations from seamount' and basin' localities in the Transdanubian Central Mountains of Hungary are lithologically, mineralogically and chemically similar to some modern marine ferromanganese oxide deposits, and show no evidence of postdepositional changes other than cementation. Five groups of deposits were encountered: Fe/Mn nodules, encrusted shells, pavements, stains, and Fe oxide encrusted intraclasts, the first three of which are specific to the 'seamount' environment and the last to the basins'. Optical and electron microprobe investigation of the samples shows them to exhibit many similarities with modern ferromanganese oxide deposits, and that many of the nodules are surrounded by a halo of dispersed ferromanganese oxides, strongly suggesting that they continued to accrete metals through the pore waters of unlithified sediments for a period after burial. By contrast, pavements which appear to have grown on hardgrounds at the sea floor show little or no evidence of derivation of metals from underlying sediments. Geochemical investigations on the deposits show the seamount' varieties to be closer in composition to most modern nodules and crusts than the basin' varieties, and that the latter are essentially manganese and trace-element-poor ferruginous deposits. Nevertheless, all can be more or less compositionally equated with modern ferromanganese oxide deposits forming in marginal Atlantic environments, which would be in accord with the proposed depositional environment of the Transdanubian Central Mountains based on other evidence.