Search

Ba/Cashell, Mo/Cashell, and Li/Cashellchronologies of Pecten maximuscan provide information on past phytoplankton dynamics. Distinct Ba, Mo, and Li peaks in the shells are associated with algal blooms. This study evaluated the underlying hypothesis that respective element profiles reliably record variations in phytoplankton dynamics occurring within the water column. Therefore, the chemical content of scallops from the Bay of Brest, France, that lived on the sediment surface was compared to conspecific specimens living in a cage above the seafloor and compared with the phytoplankton abundance and the physicochemical properties of the water column. As demonstrated, Ba/Cashelland Mo/Cashellpeaks occurred contemporaneously in specimens within the cage and on the sediment, but were higher in the latter. Furthermore, element/Ca peaks agreed with the timing of particulate Ba and Mo enrichments in the seawater. These data support the assumption of a dietary uptake of both elements. Differences in peak heights between shells living in a cage and on the seafloor were controlled by rates of filtration and biomineralization. While the timing and magnitude of Ba/Cashellpeaks were linked to Ba‐containing diatoms, Mo/Cashellpeaks were related to blooms of Mo‐enriched dinoflagellate and diatom aggregation events. Two episodes of slight Li enrichment occurred synchronously in cage and sediment shells. Although the exact mechanism causing such Li increases remains unresolved, the findings suggest a link to large diatom blooms or the presence of a specific diatom taxon. This study refines previously hypothesized relationships between trace element enrichments in scallop shells and phytoplankton dynamics.

The 72‐foot sailing yacht Eugen Seiboldis a new research platform for contamination‐free sampling of the water column and atmosphere for biological, chemical, and physical properties, and the exchange processes between the two realms. Ultimate goal of the project is a better understanding of the modern and past ocean and climate. Operations started in 2019 in the Northeast Atlantic, and will focus on the Tropical Eastern Pacific from 2023 until 2025. Laboratories for air and seawater analyses are equipped with down‐sized and automated state‐of‐the‐art technology for a comprehensive description of the marine carbon system including CO2concentration in the air and sea surface, pH, macro‐, and micro‐nutrient concentration (e.g., Fe, Cd), trace metals, and calcareous plankton. Air samples are obtained from ca. 13 m above sea surface and analyzed for particles (incl. black carbon and aerosols) and greenhouse gases. Plankton nets and seawater probes are deployed over the custom‐made A‐frame at the stern of the boat. Near Real‐Time Transfer of underway data via satellite connection allows dynamic expedition planning to maximize gain of information. Data and samples are analyzed in collaboration with the international expert research community. Quality controlled data are published for open access. The entire suite of data facilitates refined proxy calibration of paleoceanographic and paleoclimate archives at high temporal and spatial resolution in relation to seawater and atmospheric parameters. The new research sailing yacht Eugen Seibold(ES) enables clean, contamination‐free sampling of air and seawater to better understand the interactions between ocean and climate. For example, the oceans remove increasingly less carbon dioxide (CO2) from the atmosphere the more saturated they are with CO2(ocean acidification). However, a detailed systematic understanding of air‐sea exchange processes remains to be developed. We analyze air and seawater as well as the exchange of greenhouse gases and other substances such as aerosols and soot (black carbon) between air and seawater at high resolution using modern materials and technologies. Scaled‐down, energy‐efficient, and automated probes developed over the past decade are being used to measure around 50 different characteristics of the marine environment. The work deck at the stern of the boat allows the use of custom‐made water samplers and plankton nets to study the ocean to below 1,000 m depth. In addition, the new data enables a better understanding of past ocean archives, such as the marine plankton accumulated in seafloor sediments, to reconstruct past climate changes. From 2019 to 2022, the S/Y ESsailed in the eastern North Atlantic and will operate in the tropical eastern Pacific until 2025. New research platform for contamination‐free sampling of the water column and atmosphere of biological, chemical, and physical propertiesComprehensive marine geochemical analyzes including carbon (e.g., CO2) in air and sea surfaceProxy calibration of paleoclimate archives at high temporal and spatial resolution in relation to seawater and atmospheric parameters New research platform for contamination‐free sampling of the water column and atmosphere of biological, chemical, and physical properties Comprehensive marine geochemical analyzes including carbon (e.g., CO2) in air and sea surface Proxy calibration of paleoclimate archives at high temporal and spatial resolution in relation to seawater and atmospheric parameters

Phytoplankton dynamics in coastal ecosystems is increasingly altered by land‐based human activities. Yet, this global vision conceals major disparities, among sites and through time. As conventional monitoring time series are quite sparse and relatively short, biological records of environmental variability appear as relevant tools to gain insights into phytoplankton dynamics over larger temporal and spatial scales. Here, we present results of an interdisciplinary project dealing with chemical information archived in shells of Pecten maximus(Bivalvia; Pectinidae), known to form daily growth striae on its shell surface. Several individuals were collected in the Bay of Brest (France) in 2011 and 2012, and analyzed for the molybdenum and lithium concentrations in their soft tissues and the element‐to‐calcium ratios (Mo : Ca and Li : Ca) in their calcitic striae. All shells revealed high synchrony and reproducibility in their Mo : Ca and Li : Ca profiles, characterized with a major peak at the end of May and in mid‐June 2011, respectively. Detailed analysis of physical, chemical, and biological variables measured in seawater during an extensive 9‐month environmental survey enabled a meticulous description of phytoplankton dynamics in 2011 and its impact on shell geochemistry. Main findings strongly suggest that (1) the timing of Mo : Ca peaks reflects the occurrence of silicon limitation and diatom aggregation periods, (2) the height of these peaks relates to the amplitude of the first spring diatom bloom, and (3) Li : Ca serves as a proxy for the temporal dynamics of diatom biovolume and of biogenic silica recycling at the sediment–water interface.

The climate of the western Mediterranean was characterized by a strong precipitation gradient during the Holocene driven by atmospheric circulation patterns. The scarcity of terrestrial paleoclimate archives has precluded exploring this hydroclimate pattern during Marine Isotope Stages 5 to 3. Here we present stable carbon and oxygen isotope records from three flowstones from southeast Iberia, which show that Dansgaard/Oeschger events were associated with more humid conditions. This is in agreement with other records from the Iberian Peninsula, the Mediterranean, and western Europe, which all responded in a similar way to millennial‐scale climate variability in Greenland. This general increase in precipitation during Dansgaard/Oeschger events cannot be explained by any present‐day or Holocene winter atmospheric circulation pattern. Instead, we suggest that changes in sea surface temperature played a dominant role in determining precipitation amounts in the western Mediterranean. Climate events characterized by a sudden temperature increase of up to 10 °C occurring in less than a few decades during the last glacial are recorded in Greenland ice cores. These abrupt warmings, the Dansgaard/Oeschger events, affected large regions of the Northern Hemisphere. The understanding of the regional response in precipitation during these climate shifts is limited for the western Mediterranean, due to the restricted number of terrestrial climate records that cover the last glacial period at sufficient resolution. Speleothems and their stable isotope compositions allow to trace changes in climate and vegetation based on an accurate chronological framework. Here we present a speleothem stable isotope record that shows that the Dansgaard/Oeschger events were associated with increased rainfall and a denser vegetation in the western Mediterranean. A similar pattern was observed for western Europe and other parts of the Mediterranean, and we propose that this was related to generally higher sea surface temperatures of the surrounding oceans rather than a reorganization of atmospheric circulation. Western Mediterranean precipitation responded to Greenland interstadials and stadials in a coherent mannerDansgaard/Oeschger interstadials were accompanied by humid climate conditions over the western MediterraneanAtmospheric circulation patterns did not induce spatial differences in precipitation during the last glacial as they did during the Holocene

The North Atlantic Oscillation is the dominant atmospheric pressure mode in the North Atlantic region and affects winter temperature and precipitation in the Mediterranean, northwest Europe, Greenland, and Asia. The index that describes the sea-level pressure difference between Iceland and the Azores is correlated with a dipole precipitation pattern over northwest Europe and northwest Africa. How the North Atlantic Oscillation will develop as the Greenland ice sheet melts is unclear. A potential past analogue is the early Holocene, during which melting ice sheets around the North Atlantic freshened surface waters, affecting the strength of the meridional overturning circulation. Here we present a Holocene rainfall record from northwest Africa based on speleothem δ18O and compare it against a speleothem-based rainfall record from Europe. The two records are positively correlated during the early Holocene, followed by a shift to an anti-correlation, similar to the modern record, during the mid-Holocene. On the basis of our simulations with an Earth system model, we suggest the shift to the anti-correlation reflects a large-scale atmospheric and oceanic reorganization in response to the demise of the Laurentide ice sheet and a strong reduction of meltwater flux to the North Atlantic, pointing to a potential sensitivity of the North Atlantic Oscillation to the melting of ice sheets.

The synthesis of siliceous spicules in both demosponges and hexactinellids is enzymatically driven via silicatein. This enzyme exists both intra‐spicularly and in the extra‐spicular space. It catalyzes the formation of bio‐silica constituting the silica lamellae that are formed during the appositional (layer‐by‐layer) growth of the spicules. The extent of (bio‐silica forming) activity of silicatein from the demosponge Suberites domuncula measured in vitro reflects the amount of bio‐silica required for the formation of spicules in vivo. It is shown that during growth and maturation of the spicules in demosponges a bio‐fusion process occurs that results in an intra‐spicular sintering of the silica lamellae to form compact silica rods. The morphological characterization of the globular asters (microscleres) from the demosponge Geodia cydonium revealed that these spherical spicules are formed from a tuft of silicatein filaments which radiate from a common origin. While in demosponges a complete intra‐spicular bio‐sintering/bio‐fusion process occurs, this process is incomplete in hexactinellid spicules. There, only the most inner lamellae of the spicules fuse leaving the more peripheral silica lamellae separate. However, within this class of sponges several families (example Euplectella aspergillum) show a bio‐sintering process between individual spicules. There, bio‐silica is secondarily deposited onto mature spicules, giving rise to an ordered array of bio‐silica bridges. Furthermore we report that for the formation of the strong and stiff bio‐silica skeleton of sponges a hardening process is required that is (presumable) driven by cell‐membrane bound aquaporin channels which allow the removal of water, released during the bio‐silica polycondensation reaction.

This review gives an overview of the use and development of reference materials of geochemical and environmental interest in the literature of the years 2004 and 2005. In these years the performance of existing methods has been improved and new geochemical applications using new techniques have been developed. Accordingly, there was an increasing need for new reference materials, especially for in situmicroanalysis and for precise stable isotope measurements. In addition, there was a notable trend for further characterisation of existing reference materials, mainly for the platinum‐group elements. This review focuses on five topics: reference materials for platinum‐group elements, reference glasses for in situmicroanalysis, zircon reference materials, isotopic reference materials, and the development and certification of reference materials.

We have tested the capabilities of a new 193 nm Nd:YAG laser ablation system for in situ208Pb/206Pb and 207Pb/206Pb measurements by LA-ICP-MS. Experiments were performed with MPI-DING (KL2-G, ML3B-G, ATHO-G, T1-G) and USGS (GSE-1G) reference glasses using the fast electrical scan mode (0.075 s per pass) of a single collector sector-field mass spectrometer. Mass discrimination was determined by sample-reference material (e.g., NIST SRM 612) bracketing with linear interpolation. We typically obtained an external precision for 208Pb/206Pb and 207Pb/206Pb of 0.05–0.2% RSD for 50–100 μm three-spot analyses of the low-Pb (1–10 μg g−1) MPI-DING glasses. The precision of Pb isotope ratio data of the high-Pb GSE-1G sample (366 μg g−1) was <0.2% for spot sizes ≥10 μm. Even 2 and 5 μm spot size measurements could be performed with GSE-1G. The LA-ICP-MS isotope ratio data of the MPI-DING reference glasses agree within uncertainties (about 0.05% and 0.1% for 208Pb/206Pb and 207Pb/206Pb, respectively, and 100 μm spot size analyses) with the reference values obtained from TIMS and solution MC-ICP-MS. A comparison of the 193 nm Nd:YAG laser results with those obtained from a 213 nm Nd:YAG laser system shows that there is almost a factor of two improvement in precision using the new 193 nm Nd:YAG laser. Because of lower sample consumption of the 193 nm Nd:YAG laser, the Pb detection efficiency (2.5 × 10−3) of the mass spectrometer is a factor of 2.5 higher than that using the 213 nm laser. Reasons for these improvements are the shorter wavelength (193 nm compared with 213 nm) and the shorter pulse width (2.8 ns compared to 5 ns) of the new laser ablation system. Thus, the mean particle size of the ablated material and the localized heating of the sample is reduced, leading to a more uniform mass discrimination.

We have developed a new database named GeoReM () for reference materials and isotopic standards of geochemical and mineralogical interest. Reference samples include rock powders originating from the USGS, GSJ, GIT‐IWG, synthetic and natural reference glasses originating from NIST, USGS, MPI‐DING, as well as mineral (e.g., 91500 zircon), isotopic (e.g., La Jolla, E&A, NIST SRM 981), river water and seawater reference materials. GeoReM is a relational database, which strongly follows the concept of the three EARTHCHEM databases. It contains published analytical and compilation values (major and trace element concentrations, radiogenic and stable isotope ratios), important metadata about the analytical values, such as uncertainty, uncertainty type, method and laboratory. Sample information and references are also included. Three different ways of interrogating the database are possible: (1) sample names or material types, (2) chemical criteria and (3) bibliography. Some typical applications are described. GeoReM currently (October 2005) contains more than 750 geological reference materials, 6000 individual sets of results and references to 650 publications.

The USGS reference glasses GSA‐1G, GSC‐1G, GSD‐1G, GSE‐1G, BCR‐2G, BHVO‐2G and BIR‐1G were investigated by different analytical techniques. All these materials have a geological (basaltic) matrix and are therefore useful in igneous geochemistry as matrix‐matched reference materials for microanalytical techniques. The new GS glasses have trace elements in groups at concentration levels of about < 0.01, 5, 50 and 500 μg g‐1. Their major element compositions have been determined by EPMA, and trace elements have been analysed by LA‐ICP‐MS and two isotope dilution techniques using TIMS and ICP‐MS. EPMA and LA‐ICP‐MS analyses indicated that the USGS reference glasses are homogeneous at the μm to mm scale with respect to major (variations < 1‐2%) and most trace elements (variations 1‐4%). Trace element data obtained from the different analytical techniques agreed within an uncertainty of 1‐5%, indicating that between method results are comparable. Therefore, the preliminary working values for the four USGS GS glasses calculated from these data have a low level of uncertainty.

We present a multi‐element technique for the simultaneous determination of twelve trace elements in geological materials by combined isotope dilution (ID) sector field inductively coupled plasma‐mass spectrometry (SF‐ICP‐MS) following simple sample digestion. In addition, the concentrations of fourteen other trace elements have been obtained using the ID determined elements as internal standards. This method combines the advantages of ID (high precision and accuracy) with those of SF‐ICP‐MS (multi‐element capability, fast sample processing without element separation) and overcomes the most prevailing drawbacks of ICP‐MS (matrix effects and drift in sensitivity). Trace element concentration data for BHVO‐1 (n = 5) reproduced to within 1–3% RSD with an accuracy of 1–2% relative to respective literature values for ID values and 2–3% for all other values. We have applied this technique to the analysis of seventeen geological reference materials from the USGS, GSJ and IAG. The sample set also included the new USGS reference glasses BCR‐2G, BHVO‐2G and BIR‐1G, as well as the MPI‐DING reference glasses KL2‐G and ML3B‐G, and NIST SRM 612. Most data agreed within 3–4% with respective literature data. The concentration data for the USGS reference glasses agreed in most cases with respective data of the original rock powder within the combined standard uncertainty of the method (2–3%), except the U concentration of BIR‐1G, which showed a three times higher concentration compared to BIR‐1.

We have measured 87Sr/86Sr and 143Nd/144Nd isotope ratios in different batches and aliquots of the new US Geological Survey (USGS) reference materials (RMs) BCR‐2, BHVO‐2, AGV‐2 and GSP‐2 and the original USGS RMs BCR‐1, BHVO‐1, AGV‐1 and GSP‐1 by thermal ionisation mass spectrometry. In addition, we also analysed the eight Max‐Planck‐Institut‐Dingwell (MPI‐DING) reference glasses. Nearly all isotope ratios obtained in the different aliquots and batches agree within uncertainty limits indicating excellent homogeneity of the USGS powders and the MPI‐DING glasses. With the exception of GSP‐2, the new USGS RMs are also indistinguishable from the ratios found in the original USGS RMs (87Sr/86Sr: 0.704960, 0.704958 (BCR‐1, ‐2), 0.703436, 0.703435 (BHVO‐1, ‐2), 0.703931, 0.703931 (AGV‐1, ‐2); 143Nd/144Nd: 0.512629, 0.512633 (BCR‐1, ‐2), 0.512957, 0.512957 (BHVO‐1, ‐2); 0.512758, 0.512755 (AGV‐1, ‐2)). This means that for normalisation purposes in Sr and Nd isotope geochemistry BCR‐2, BHVO‐2 and AGV‐2 can well replace BCR‐1, BHVO‐1 and AGV‐1 respectively.

Eight silicate glasses were prepared by directly fusing and stirring 50‐100 g each of basalt, andesite, komatiite, peridotite, rhyolite, and quartz‐diorite. These are referred to as MPI‐DING glasses and were made for the purpose of providing reference materials for geochemical, in‐situ microanalytical work. Results from various analytical techniques indicate that individual glass fragments are well homogenised with respect to major and trace elements at the μm to mm scale. Heterogeneities due to quench crystallisation of olivine have been observed in small and limited areas of the two komatiitic glasses. In order to obtain concentration values for as many elements as possible, the glasses were analysed by a variety of bulk and microanalytical methods in a number of laboratories. The analytical uncertainties of most elements are estimated to be between 1% and 10%. From the analytical data, preliminary reference values for more than sixty elements were calculated. The analytical uncertainties of most elements are estimated to be between 1% and 10%.

The trace element compositions of eclogites, blueschists and mafic granulites from high-pressure terranes have been analysed to investigate element losses and fractionation that occur during dehydration of oceanic basalt in subduction zones. Abundances of elements that are suggested to be near-immobile (e.g., Nb, Zr, Ti), SrNd isotopic compositions, and major element compositions indicate that most samples had altered MORB protoliths. The samples show only limited retrograde alteration, and cover a range in pressure-temperature conditions (1.2–4 GPa, 300–1000°C). In ratio diagrams, strong depletions (95–98%) of K, Rb and Ba relative to Nb and Th in most samples are obvious when compared with unaltered and altered MORB or ocean island basalts. The largest fraction of K, Rb and Ba appears to be lost at temperatures < 600–700°C. In contrast, elements such as Th, Nb, Ti, Zr, Nd, Sm and compatible elements show no evidence of significant losses (< 10–20%). U and Pb also show losses, but these are significantly less than those for K and Ba. Eclogites retain nearly all Nb during dehydration. Consequently, the depleted nature of sub-arc mantle is the most likely cause for the low Nb abundances in arc lavas. The addition of U during sub-seafloor alteration and its restricted loss during subduction zone metamorphism substantially decreases Th/U and Nb/U in subducted altered MORB. The latter observation suggests that high U/Pb of many metabasaltic eclogites may have been caused by addition of U during sub-seafloor alteration. However, the correlation of U/Pb with Nd/Pb indicates that Pb loss during dehydration is the major cause of increased U/Pb in the eclogites. Model compositions of subducted altered oceanic crust have been established at 600°C and 900°C on the basis of the composition of the high-pressure rocks. Using these data, flux models indicate that Ba and Th in typical arc magmas must be mainly sediment-derived (fluids or melts from subducted sediment or shallow crustal contamination). In contrast, a large fraction of Rb and K and < 40% of the U in arc front magmas may be provided by fluids from subducted altered basalt. The models indicate that subducted altered oceanic basalt provides less than ca. 10% of the Pb and less than 5% of Sr to average arc front magma compositions. The low estimate for Sr confirms previous indications that contributions from average altered MORB cannot explain the Sr enrichment in arc lavas. Most of the Nd, heavy rare earth elements (REE), Y, high-field strength elements (HFSE) and compatible elements in primitive arc front magmas must be supplied by the depleted mantle wedge and a sedimentary component in arc lavas.

The trace element compositions of eclogites, blueschists and mafic granulites from high-pressure terranes have been analysed to investigate element losses and fractionation that occur during dehydration of oceanic basalt in subduction zones. Abundances of elements that are suggested to be near-immobile (e.g., Nb, Zr, Ti), Sr-Nd isotopic compositions, and major element compositions indicate that most samples had altered MORB protoliths. The samples show only limited retrograde alteration, and cover a range in pressure-temperature conditions (1.2–4 GPa, 300–1000°C). In ratio diagrams, strong depletions (95–98%) of K, Rb and Ba relative to Nb and Th in most samples are obvious when compared with unaltered and altered MORB or ocean island basalts. The largest fraction of K, Rb and Ba appears to be lost at temperatures < 600–700°C. In contrast, elements such as Th, Nb, Ti, Zr, Nd, Sm and compatible elements show no evidence of significant losses (<10–20%). U and Pb also show losses, but these are significantly less than those for K and Ba. Eclogites retain nearly all Nb during dehydration. Consequently, the depleted nature of sub-arc mantle is the most likely cause for the low Nb abundances in arc lavas. The addition of U during sub-seafloor alteration and its restricted loss during subduction zone metamorphism substantially decreases Th/U and Nb/U in subducted altered MORB. The latter observation suggests that high U/Pb of many metabasaltic eclogites may have been caused by addition of U during sub-seafloor alteration. However, the correlation of U/Pb with Nd/Pb indicates that Pb loss during dehydration is the major cause of increased U/Pb in the eclogites. Model compositions of subducted altered oceanic crust have been established at 600°C and 900°Con the basis of the composition of the high-pressure rocks. Using these data, flux models indicate that Ba and Th in typical arc magmas must be mainly sediment-derived (fluids or melts from subducted sediment or shallow crustal contamination). In contrast, a large fraction of Rb and K and < 40% of the U in arc front magmas may be provided by fluids from subducted altered basalt. The models indicate that subducted altered oceanic basalt provides less than ca. 10% of the Pb and less than 5% of Sr to

National Institute of Science and Technology (NIST) silicate glass SRM 610 is widely used as a certified reference material for various micro‐analytical techniques such as SIMS or laser ablation ICP‐MS. SRM 610 has been nominally doped with sixty one trace elements at the 500 μg g−1level, but certified concentration data exist for only a few of these elements. This study reports concentration data for fifty nine trace elements obtained by ICP‐MS, SSMS, LIMS, TIMS, INAA, AAS, and PIXE analyses of two different SRM 610 wafers. Most elements fall within a 10% band around a median value of about 440 μg g−1. The REE concentrations are shown to be constant to 3% (1 σ), thus emphasizing the value of SRM 610 as a reference material for REE analyses.

X-ray microspectroscopy is a powerful analytical method in geoscientific and environmental research as it provides a unique combination of nanoscale imaging with high spectroscopic sensitivity at relatively low beam-related sample damage. In this study, “classical” scanning transmission soft X-ray microscopy (STXM) with X-ray absorption spectroscopy and the recently established soft X-ray ptychography are applied to the analysis of selected rock varnish samples from urban and arid desert environments. X-ray ptychography enhances the spatial resolution relative to STXM by up to 1 order of magnitude. With its high chemical sensitivity, it can resolve nanoscale differences in valence states of the key varnish elements manganese (Mn) and iron. Our results emphasize the complex nanoarchitecture of rock varnish as well as the diverse mineralogy of the Mn oxy–hydroxide matrix and its embedded dust grains. In contrast to the fast-growing urban varnish, the slow-growing arid desert varnish revealed a remarkable nanoscale stratification of alternating Mn valence states, providing hints on the layer-wise and still enigmatic growth process.

In 2005 Geostandards and Geoanalytical Research embarked upon a new initiative for its readers. Key researchers in various fields of geoanalytical technique development and their application were identified and invited to provide reviews pertinent to their expertise. As noted in the first of these publications “…instead of revisiting the historical context or decades of development in each analytical technique, the goal here has been to capture a snapshot of “hot topics” across a range of fields as represented in the… literature” (Hergt et al. 2005). Rather than prepare an annual review, a decision was taken earlier this year to provide a biennial summary of progress and accomplishments, in this case for the years 2004–2005. The principal techniques employed in Earth and environmental sciences are covered here, and include laser ablation and multicollector ICP‐MS, ICP‐AES, thermal ionisation and secondary ion mass spectrometry, as well as neutron activation analysis, X‐ray fluorescence and atomic absorption spectrometry. A comprehensive review of the development of reference materials, often essential to these techniques, is also provided. The contributions assembled serve both to keep readers informed of advances they may be unfamiliar with, but also as a means of showcasing examples of the breadth and depth of work being conducted in these fields.