Major and trace element composition of clinopyroxenes from an olivine gabbro of ODP Hole 176-735B (Table 1)

Major and trace element profiles of clinopyroxene grains in oceanic gabbros from ODP Hole 735B have been investigated by a combined in situ analytical study with ion probe, and electron microprobe. In contrast to the homogeneous major element compositions, trace elements (REE, Y, Cr, Sr, and Zr) show continuous core to rim zoning profiles. The observed trace element systematics in clinopyroxene cannot be explained by a simple diffusive exchange between melts and gabbros along grain boundaries. A simultaneous modification of the melt composition is required to generate the zoning, although Rayleigh fractional crystallization modelling could mimic the general shape of the profiles. Simultaneous metasomatism between the cumulate crystal and the porous melt during crystal accumulation is the most likely process to explain the zoning. Deformation during solidification of the crystal mush could have caused squeezing out of the incompatible element enriched residual melts (interstitial liquid). Migration of the melt along grain boundaries might carry these melt out of the system. This process named as synkinematic differentiation or differentiation by deformation (Natland and Dick, 2001, doi:10.1016/S0377-0273(01)00211-6) may act as an important magma evolution mechanism in the oceanic crust, at least at slow-spreading ridges.

(Table 2) Trace element contents in ancient Black Sea sapropelic muds

The study of vertical distribution of Mo, V, Co, Ni, and Cu in mass of Black Sea sediments showed that maximum concentrations occur in sapropelic muds of ancient Black Sea deposits. A special study of sapropels samples showed a sufficiently clear correlation of Cu, Ni, Mo, and V contents with organic carbon contents; Co contents do not show such a correlation, but show one with contents of pyrite sulfur. A study of fractions of bitumen, free humic and fulvic acids showed that some part of metal contents in the sediments is bound with organic matter. It is shown that increased concentrations of trace elements in sapropels result from removing of dissolved metals from seawater by organic detritus during deposition on the bottom, in vivo concentration of metals in plankton organisms is of secondary importance.

(Table T1) Trace element concentration and isotopic composition of pore waters from ODP Leg 168 sites

Pore water was collected from each of 10 sites during Ocean Drilling Program (ODP) Leg 168 on the eastern flank of the Juan de Fuca Ridge. These ten sites delineate a transect perpendicular to the present ridge axis and span a crustal age of 0.86-3.59 Ma. At nine of the ten sites the entire sediment section, which ranged from 41.3 to 613.8 m thick, was cored and attempts were made to recover at least one whole round of sediment per section of core for extraction of pore water. Several (2-5) whole-round sediment samples were taken from the uppermost and lowermost cores to constrain the chemical gradient near the sediment/water and sediment/basalt interfaces, respectively. Pore water was extracted from whole-round sediment core sections by squeezing only the most pristine sediment in a titanium squeezer designed by Manheim and Sayles (1974). Two additional water samples were collected in situ using the water-sampler temperature probe (WSTP; Barnes, 1988, doi:10.2973/odp.proc.ir.110.104.1988). Both of these samples were collected in the cased section of the open borehole from ODP Hole 1026B. Formation fluids were flowing up the cased hole into the overlying deep seawater (Fisher et al., 1997, doi:10.1029/97GL01286). Detailed descriptions of the sampling methods that were used to collect fluids are given by the Shipboard Scientific Party (Davis, Fisher, Firth, et al., 1997, doi:10.2973/odp.proc.ir.168.1997).

(Table 1) Minor and trace element concentrations in interstitial waters from ODP Leg 166 sites

Concentrations of minor and trace elements (Li, Rb, Sr, Ba, Fe, and Mn) in interstitial water (IW) were found in samples collected during Ocean Drilling Program (ODP) Leg 166 from Sites 1005, 1006, and 1007 on the western flank of the Great Bahama Bank (GBB). Concentrations of Li range from near-seawater values immediately below the sediment/water interface to a maximum of 250 µM deep in Site 1007. Concentrations determined during shore-based studies are substantially lower than the shipboard data presented in the Leg 166 Initial Reports volume (range of 28-439 µM) because of broad-band interferences from high dissolved Sr concentrations in the shipboard analyses. Rubidium concentrations of 1.3-1.7 µM were measured in IW from Site 1006 when salinity was less than 40 psu. A maximum of 2.5 µM is reached downhole at a salinity of 50 psu. Shipboard and shore-based concentrations of Sr2+ are in excellent agreement and vary from 0.15 mM near the sediment water interface to 6.8 mM at depth. The latter represent the highest dissolved Sr2+ concentrations observed to date in sediments cored during the Deep Sea Drilling Project (DSDP) or ODP. Concentrations of Ba2+ span three orders of magnitude (0.1-227µM). Concentrations of Fe (<0.1-14 µM) and Mn (0.1-2 µM) exhibit substantially greater fluctuations than other constituents. The concentrations of minor and trace metals in pore fluids from the GBB transect sites are mediated principally by changes in pore-water properties resulting from early diagenesis of carbonates associated with microbial degradation of organic matter, and by the abundance of detrital materials that serve as a source of these elements. Downcore variations in the abundance of detrital matter reflect differences in carbonate production during various sea-level stands and are more evident at the more proximal Site 1005 than at the more pelagic Site 1006. The more continuous delivery of detrital matter deep in Site 1007 and throughout all of Site 1006 is reflected in a greater propensity to provide trace elements to solution. Concentrations of dissolved Li+ derive principally from (1) release during dissolution of biogenic carbonates and subsequent exclusion during recrystallization and (2) release from partial dissolution of Li-bearing detrital phases, especially ion-exchange reactions with clay minerals. A third but potentially less important source of Li+ is a high-salinity brine hypothesized to exist in Jurassic age (unsampled) sediments underlying those sampled during Leg 166. The source of dissolved Sr2+ is almost exclusively biogenic carbonate, particularly aragonite. Concentrations of dissolved Sr2+ and Ba2+ are mediated by the solubility of their sulfates. Barite and detrital minerals appear to be the more important source of dissolved Ba2+. Concentrations of Fe and Mn2+ in anoxic pore fluids are mediated by the relative insolubility of pyrite and incorporation into diagenetic carbonates. The principal sources of these elements are easily reduced Fe-Mn-rich phases including Fe-rich clays found in lateritic soils and aoelian dust.

Trace element geochemistry at DSDP Leg 82 Holes

Forty-three samples from DSDP Holes 556-559 and 561-564 were analyzed for rare earth elements (REE), Sc, Cr, Co, Hf, Ta, and Th by instrumental neutron activation analysis. The recovered basalts range from those depleted in light REE (LREE) to those enriched in LREE. The two types of basalts occur together in Holes 558 and 561. The depleted basalts have remarkably constant La/Yb, La/Sm, and La/Ti ratios and apparently derive from a large, homogeneous, mantle source underneath a segment (1200 km long) of the Mid-Atlantic Ridge. The almost twofold variation in the concentrations of incompatible trace elements in the depleted basalts is primarily due to different degrees of batch partial melting. The variation of highly to moderately incompatible elements in the Leg 82 enriched basalts can be successfully explained in terms of source mixing between depleted mantle sources and alkaline or nephelinitic magmas similar to Azores Islands magmas. However, the correlation of LREE enrichment with distance from the Azores Triple Junction is tenuous at best, and the enriched alkaline component is probably not directly related to the Azores volcanism.

Data compilation on the biological response to ocean acidification: environmental and experimental context of data sets and related literature

The exponential growth of studies on the biological response to ocean acidification over the last few decades has generated a large amount of data. To facilitate data comparison, a data compilation hosted at the data publisher PANGAEA was initiated in 2008 and is updated on a regular basis (doi:10.1594/PANGAEA.149999). By January 2015, a total of 581 data sets (over 4 000 000 data points) from 539 papers had been archived. Here we present the developments of this data compilation five years since its first description by Nisumaa et al. (2010). Most of study sites from which data archived are still in the Northern Hemisphere and the number of archived data from studies from the Southern Hemisphere and polar oceans are still relatively low. Data from 60 studies that investigated the response of a mix of organisms or natural communities were all added after 2010, indicating a welcomed shift from the study of individual organisms to communities and ecosystems. The initial imbalance of considerably more data archived on calcification and primary production than on other processes has improved. There is also a clear tendency towards more data archived from multifactorial studies after 2010. For easier and more effective access to ocean acidification data, the ocean acidification community is strongly encouraged to contribute to the data archiving effort, and help develop standard vocabularies describing the variables and define best practices for archiving ocean acidification data.

(Table 1, page 754) Estimated concentrations of various elements in nineteen manganese nodules

Using spectrochemical techniques Fe, Si, Mg, Co, Ni, Cu, V, Mo, Ti and Tl have been estimated in nineteen manganese nodules, eight from the Atlantic ocean, seven from the Pacific ocean and four from the Indian ocean. Though data on more samples are required before firm and detailed conclusions can be made about the distribution of elements in manganese nodules, several distinct features appear when the data on the nineteen samples are examined. Certain elements appear to enrich more strongly than others. For example, relative to igneous rocks Mo is much more strongly enriched than V. For several elements (Ni, Cu and particularly Co and Tl) the degree of enrichment in two Fe-low nodules is far smaller than in the other nodules. The magnitude of dispersion of concentration appears to vary considerably for different elements; thus, whereas variation of concentration of V is relatively small, that of Ni, Cu, Co and Tl is far larger. The statistical nature of the distribution of Fe in manganese nodules appears to be characteristic and different from that of the other elements studied so far. Of the possible inter-element relationships examined that of Ni-Cu appears to be the most strongly developed.

Trace element contents in bottom sediments from the North Indian Ocean

Contents and distributions of Cu, Ni, Co, V, Cr, Zn, Pb, Mo, W, and Zr in near-coast and pelagic sediments of the Northern Indian Ocean are under consideration in the paper. Chemical analyses showed enrichment of pelagic clayey radiolarian oozes by Mn, Cu, Ni, Co, Pb, W, and Mo. According to enrichment factors these elements have the following order: Mo> Mn> Cu> Ni> Co> Pb> W. Enrichment of pelagic sediments from the Indian Ocean is mainly determined by the mechanism of the sedimentation process. Enrichment factors of Cu, Ni, Co, W, Mo, and Mn in pelagic sediments of the North Indian Ocean are intermediate between ones in pelagic sediments of the Pacific and Atlantic Oceans.

(Tables 1-3) Silicon dioxide, Corg and trace element concentrations in sediments of the outer Eckernfoerder Bay, Western Baltic Sea

The main question, posed in the work scheme before laboratory analysis was started, was expressed as follows: Do marked seasonal fluctuations occur in trace element content of the sediment surface, and what are the probable influences of factors such as changing hydrographical parameters, plankton sequence etc. ? Special attention was paid to elements known as pollutants, for example mercury. Within this framework samples have been analysed for their contents of manganese, iron, zinc, lead, and mercury. The amounts of silica and organically-bound carbon serve in most cases as reference values for the trace element content. On sand temporary conditions of increased C org content raise the concentrations of all determined elements. Especially the values reached for mercury in July are worth nothing. It is concluded that Zn, Pb, and Hg tend to enrich with respect to C org as the decomposition of organic matter progresses. On mud-sand flocculation and precipitation of Mn/Fe-hydroxides probably represent an additional concentrating factor for the other elements as the relationship of the results for zinc and manganese shows. Manganese may indicate a seasonally related concentrating cycle at the sediment surface.

(Table T1) Trace-element abundances for igneous basement at ODP Site 206-1256

In this report, I present trace element data for basement samples at Ocean Drilling Program (ODP) Site 1256. The samples analyzed represent a subset of the group ("pool") samples from ODP Leg 206, and these trace element data are part of a more comprehensive data suite for the same samples, with analyses of stable and radiogenic isotopes (e.g., Sr, Li, and O) in progress or recently completed that will be presented elsewhere. The trace element analyses were performed in the GeoAnalytical Lab at Washington State University. The following elements were analyzed: La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Ba, Th, Nb, Y, Hf, Ta, U, Pb, Rb, Cs, Sr, Sc, and Zr. Trace element data indicate that the igneous basement at Site 1256 is geochemically normal mid-ocean-ridge basalt. A massive ponded flow sampled in both Holes 1256C and 1256D is distinguished by higher abundances of rare earth elements (REE) and most of the other trace elements analyzed. One interval of highly altered basalt has significantly higher concentrations of Cs, Rb, and Ba and lower concentrations of Sr, Pb, Zr, Hf, Sc, and most REE than the samples of background alteration or halos. No correlation is obvious between trace element abundance and macroscopic type of alteration within the background alteration or halos.

Sr/Ca and Cd/Ca ratios of benthic foraminifera in surface deep-sea sediments

Measurements of Sr/Ca of benthic foraminifera show a linear decrease with water depth which is superimposed upon significant variability identified by analyses of individual foraminifera. New data for Cd/Ca support previous work in defining a contrast between waters shallower and deeper than ~2500 m. Measured element partition coefficients in foraminiferal calcium carbonate relative to sea water (D) have been described by means of a one-box model in which elements are extracted by Rayleigh distillation from a biomineralization reservoir that serves for calcification with a constant fractionation factor (alpha), such that D = (1 - f**alpha)/(l - f), where f is the proportion of Ca remaining after precipitation. A modification to the model recognises differences in element speciation. The model is consistent with differences between D[Sr], D[Ba], and D[Cd] in benthic but not planktonic foraminifera. Depth variations in D for Sr and Ba are consistent with the model, as are differences in depth variation of D[Cd] in calcitic and aragonitic benthic foraminifera. The shallower depth variations may reflect increasing calcification rates with increasing water depth to an optimum of about 2500 m. Observations of unusually lower DCd for some deep waters, not accompanied by similar [Sr], or D[Ba] may be because of dissolution or a calcification response to a lower carbonate saturation state.

Trace element composition of IODP Site 304-U1309 and 305-U1309 (Table A2)

IODP Site U1309 was drilled at Atlantis Massif, an oceanic core complex, at 30°N on the Mid-Atlantic Ridge (MAR). We present the results of a bulk rock geochemical study (major and trace elements) carried out on 228 samples representative of the different lithologies sampled at this location. Over 96% of Hole U1309D is made up of gabbroic rocks. Diabases and basalts cross-cut the upper part of the section; they have depleted MORB compositions similar to basalts sampled at MAR 30°N. Relics of mantle were recovered at shallow depth. Mantle peridotites show petrographic and geochemical evidence of extensive melt-rock interactions. Gabbroic rocks comprise: olivine-rich troctolites (> 70% modal olivine) and troctolites having high Mg# (82-89), high Ni (up to 2300 ppm) and depleted trace element compositions (Yb 0.06-0.8 ppm); olivine gabbros and gabbros (including gabbronorites) with Mg# of 60-86 and low trace element contents (Yb 0.125-2.5 ppm); and oxide gabbros and leucocratic dykes with low Mg# (< 50), low Ni (~65 ppm) and high trace element contents (Yb up to 26 ppm). Troctolites and gabbros are amongst the most primitive and depleted oceanic gabbroic rocks. The main geochemical characteristics of Site U1309 gabbroic rocks are consistent with a formation as a cumulate sequence after a common parental MORB melt, although (lack of systematic) downhole variations indicate that the gabbroic series were built by multiple magma injections. In detail, textural and geochemical variations in olivine-rich troctolites and gabbronorites suggest chemical interaction (assimilation?) between the parental melt and the intruded lithosphere. Site U1309 gabbroic rocks do not represent the complementary magmatic product of 30°N volcanics, although they sample the same mantle source. The bulk trace element composition of Site U1309 gabbroic rocks is similar to primitive MORB melt compositions; this implies that there was no large scale removal of melts from this gabbro section. The occurrence of such a large magmatic sequence implies that a high magmatic activity is associated with the formation of Atlantis Massif. Our results suggest that almost all melts feeding this magmatic system stays trapped into the intruded lithosphere.