This dataset includes downcore measurements of pH values, H2S, Cl-, SO42-, SiO2, NO2-, PO43-, NH4+, NO3-, As, Ba, Ca, Cu, Fe, K, Li, Mg, Mn, Mo, P, Si and Sr concentrations for sediment cores retrieved using multi-corer sampling during RV Heincke expeditions HE575 and HE595 in 2021 and 2022, respectively. The samples were collected in the framework of the Project APOC (Anthropogenic impacts on particulate organic carbon cycling in the North Sea). All measurements were performed in the laboratories of the Alfred Wegener Institute (AWI) in Bremerhaven, Germany, except pH values, which were determined onboard the research vessel.
Eine Elementkarte stellt die räumliche Verteilung der klassifizierten Gehalte eines der 39 ausgewerteten Haupt-, Neben- oder Spurenelemente innerhalb der 184 geochemischen Gesteinseinheiten in Bayern dar. In die Auswertung gehen dabei nur die Daten der ersten (von maximal drei) Lithologien einer geochemischen Gesteinseinheit ein. Elementkarten werden jeweils für das 50. und 90. Perzentil vorgehalten. Die Gehalte der Hauptelemente sind in Gew.-% angegeben, die Gehalte der Neben- oder Spurenelemente sind in mg/kg angegeben. Für Informationen im Hinblick auf die Auswertung der Daten sowie auf die kartenmäßige Darstellung wird auf die Metadaten der digitalen Lithogeochemischen Karte von Bayern 1:25 000 (dLGK25) verwiesen.
This database expands the Poulton et al., 2018 (doi:10.1594/PANGAEA.888182) database of pelagic calcium carbonate (CP) rate measurements from isotopic tracer uptake in incubated discrete water samples, as discussed in Daniels et al., 2018 (doi:10.5194/essd-10-1859-2018), and accompanies Marsh et al. (in prep.). The database now includes more CP (new data n = 400; complete database n = 3165), net primary production rate (PP) (new data n = 399; complete database n = 3150), total coccolithophore cell counts (new data n = 240; complete database n = 1512), and Emiliania huxleyi cell counts (new data n = 27; complete database n = 612). This expanded database maintains the record of data, including the principal investigator, expedition, OS region, doi reference (where available), collection date and year, sample ID, latitude, longitude, sampling and light depth, and method of measuring CP. We further expand the Poulton et al. (2018) data collection by including ancillary and environmental data, including: optical depth (OD, n = 3165), pHtotal (hereinafter referred to as pHT, n = 398), temperature (n = 1160), salinity (n = 1161), and the concentrations of chlorophyll a (n = 1363), NOx (NO3 or the sum of NO3 + NO2, n = 1161), silicic acid (Si(OH)4, n= 1156), phosphate (PO4, n = 1232), dissolved inorganic carbon (DIC, n = 318), total alkalinity (TA, n = 307), bicarbonate ion concentration (n = 349), and carbonate ion concentration (n = 352). All data was matched to CP, sample bottle identifiers (Niskin bottle numbers), and/or sampling depth values. This global database (81 °N - 64 °S, 132 °E - 174 °W) now covers expeditions and upper ocean measurements (0 - 193 m) from 1989 to 2024. Global in-situ geolocated data spanning time is valuable for modelling, satellite algorithms, and capturing calcium carbonate production in the global ocean. This expanded database, including the environmental, nutrient, chlorophyll a, and carbonate chemistry data, also allows for analysis of factors influencing calcium carbonate production on a global scale. This data amalgamation contributes to understanding the biogeochemistry of the oceans, global carbon cycle, and ocean acidification.
Diatoms account for up to 40% of marine primary production and require silicic acid to grow and build their opal shell. On the physiological and ecological level, diatoms are thought to be resistant to, or even benefit from, ocean acidification. Yet, global-scale responses and implications for biogeochemical cycles in the future ocean remain largely unknown. Here we conducted five in situ mesocosm experiments with natural plankton communities in different biomes and find that ocean acidification increases the elemental ratio of silicon (Si) to nitrogen (N) of sinking biogenic matter by 17 ± 6 per cent under pCO2 conditions projected for the year 2100. This shift in Si:N seems to be caused by slower chemical dissolution of silica at decreasing seawater pH. We test this finding with global sediment trap data, which confirm a widespread influence of pH on Si:N in the oceanic water column. Earth system model simulations show that a future pH-driven decrease in silica dissolution of sinking material reduces the availability of silicic acid in the surface ocean, triggering a global decline of diatoms by 13–26 per cent due to ocean acidification by the year 2200. This outcome contrasts sharply with the conclusions of previous experimental studies, thereby illustrating how our current understanding of biological impacts of ocean change can be considerably altered at the global scale through unexpected feedback mechanisms in the Earth system.
The 11.8 m-long composite sediment record from the hardwater lake of Sacrower See, located near the city of Potsdam (north-eastern Germany), has been characterised by a range of analytical techniques. These include magnetic susceptibility, chemical parameters (XRF core scanning, CNS analysis, biogenic silica) and stable isotopes (13C, 15N). The chronology covers the entire Holocene and the concluding Lateglacial (Alleröd, Younger Dryas) and is based on age-depth modelling using radiocarbon dates refined by the onset of the local varve chronology in 1870 CE (Lüder et al., 2006) and by the Laacher See Tephra, an isochrone dated to 13,000 cal. BP. It offers a detailed environmental reconstruction providing insights into depositional processes influenced by both natural climatic variations and human activities (Enters et al., 2009; Kirilova et al., 2009). The Lateglacial and Early Holocene are distinguished by the stabilisation of natural landscapes characterised by the presence of pine-birch (Alleröd) and mixed oak forests (Early Holocene). This development was interrupted by the climatic deterioration of the Younger Dryas, which resulted in a destabilisation of vegetation and increased natural soil erosion. It is evident that, for the first time around 5500 cal. BP, anthropogenic forest clearing became a factor, which subsequently led to increasing cultural soil erosion further accelerating during the Bronze Age (3600-3200 cal. BP), the Early Iron Age (2800-2600 cal. BP) and the Middle Ages (900-600 cal. BP). In the course of industrialisation since the 19th century, human impact underwent a transition from the destabilisation of soils to the phenomenon of eutrophication. This transition resulted in the occurrence of hypolimnetic anoxia, accompanied by the formation of carbonaceous varves.
Unraveling the role of the Southern Ocean's biological pump in regulating climate would be enhanced by the development of paleoceanographic proxies specific to carbon or silica cycling. Observations that the average size of valves of the diatom, Fragilariopsis kerguelensis, varies seasonally, with latitude, and over glacial-interglacial cycles in the Southern Ocean suggest that the valve size frequency distribution in sediments could be used to reconstruct aspects of paleoproductivity and silica cycling. We aim to develop this proxy by using culture, field and sediment samples to determine the exact controls on valve size frequency distributions, the most important of which is likely to be the frequency of auxospore formation within the population. The controls on auxospore formation are as yet unknown and both mating experiments in culture as well as in situ iron fertilization experiments are likely to unravel the mechanisms determining auxospore formation under both controlled and field conditions. The valve size frequency distribution can then be used to indicate the intensity of the environmental and/or biological conditions triggering auxospore formation.
Die Nukleation von Eispartikeln spielt eine wichtige Rolle bei der Wolken- und Niederschlagsbildung, mit Konsequenten für die atmosphärische Chemie, die Wolkenphysik und das Erdklima. Für eine Quantifizierung und Vorhersage des Einflusses von Wolken in Wettervorhersage- und Klimamodellen muss die Bildung von Eispartikeln daher in einer realistischen Art und Weise beschrieben werden. Einer der wichtigen Bildungsmechanismen ist dabei die heterogene Eisnukleation im Immersionsmodus, bei dem Eis an der Oberfläche eines in einem wässrigen Tröpfchen suspendierten Eiskeims - zum Beispiel eines Mineralstaub- Partikels - gebildet wird. Wir werden im Rahmen dieses Forschungsprojekts zahlreiche Gefrierexperimente im Immersionsmodus durchführen. So werden eine Reihe verschiedener, als Aerosolpartikel in der Atmosphäre vorkommende Materialien auf ihre Eisnukleationseigenschaften hin untersucht werden. Insbesondere sollen hier die Temperatur- und Zeitabhängigkeit der von diesen Materialien ausgelösten Eisnukleation quantifiziert werden. Dabei werden wir spezielles Augenmerk auf die systematische Untersuchung der von porösen Materialien ausgelösten Eisnukleation legen. Es sollen sowohl synthetische Materialien wie beispielsweise mesoporöse Silikate untersucht werden, als auch natürlich vorkommende Materialien wie etwa mikroporöse Zeolithe.
In the project "Geochemistry and geochronology of the Heldburg dyke swarm, Central European Volcanic Province" we conducted geochemical and geochronological investigations on mafic dykes and former magma chambers of the Heldburg dyke swarm. The latter is part of the Central European Volcanic Province and positioned in the South of Thuringia and the North of Bavaria (Germany). It consists of several hundred mafic NNE-SSW striking dykes with an usual thickness of < 1m and few former magma chambers. All of these have an atypical position within the Central European Volcanic Province located away from Hercynian massifs and major rift axes and were hitherto poorly investigated. In general, 10 different locations of the Heldburg dyke swarm were sampled for whole-rock analyses and 4 different locations were chosen for determining their apatite and zircon ages. The fieldwork was conducted between March 2022 and December 2023. The analytical work was done between June 2022 and April 2024 at the Department of Geodynamics and Geomaterials Research, University of Würzburg (samples preparation, X-ray fluorescence), at the GeoZentrum Nordbayern, University of Erlangen (trace element contents, LA-ICP-MS) and at FIERCE (Frankfurt Isotope & Element Research Center), Goethe University Frankfurt (apatite and zircon ages, LA-ICP-MS). Here, we present the full dataset of 55 whole-rock chemical analyses (X-ray fluorescence, LA-ICP-MS) from ten locations of the Heldburg dyke swarm.
The Jacupiranga carbonatite (Brazil) was investigated to better understand how modal proportions and mineral chemistry control the fO2 recorded by a natural carbonatite rock. Mineral compositions were determined using SEM-EDS, EPMA-WDS and Raman microspectroscopy building upon detailed petrography. Based on magnetite-ilmenite oxythermobarometry, rock-forming temperatures range from 505 to 732 °C, with a wide span of fO2 values (∆FMQ –1.21 to +4.56). In each sample, ilmenite grains and lamellae are distinguishable, with the latter recording higher temperature–fO2 conditions. Consistently, independently determined homogenization temperatures of apatite-hosted fluid inclusions show a similar range between 550 and 685 °C. From the wall-rock contact toward the carbonatite body, samples exhibit a decrease in the modal abundance of olivine, phlogopite, magnetite, ilmenite, and dolomite, alongside an increase in Mg-calcite. Over the same spatial gradient, temperature, fO2, and the magnesioferrite (in magnetite) and geikielite (in ilmenite) components decrease. During the antiskarn reaction, silica and mafic components (Mg, FeT, Al, and Ti) derived from the ultramafic wall-rock were incorporated into olivine, phlogopite, magnetite-ilmenite, and dolomite. Calcite-rich samples, which were less influenced by the wall-rock, preserved ephemeral alkali components of the carbonatite melts within burbankite. Apatite-hosted fluid inclusions represent coeval fluid modified by antiskarn reactions. Adjacent to equilibrium magnetite-ilmenite pairs, olivine and phlogopite exhibit high mg# (93–97 and 88–95, respectively). Despite the broad span of ∆FMQ values recorded by the oxide pairs, we found only a weak positive correlation between the recorded fO2 and mg#. Consequently, we suggest that the high mg# (>88–90) of carbonatitic olivine is primarily controlled by the low (<0.2) 〖K_D〗_(Fe^(2+)-Mg)^(olivine-carbonatite melt) (Fe2+/Mg exchange partition coefficient between olivine and the carbonatite melt) at crustal conditions. The exceptionally high mg# of olivine and phlogopite, compared to the adjacent dunite cumulates (mg# 84–88), combined with their negligible Ni and Cr contents, indicate an in situ antiskarn process. This study demonstrates that carbonatite systems can be characterized by dynamic redox conditions, spanning the range from Fe3O4 ̶ Fe2O3 to Fe2SiO4 ̶ Fe3O4 ̶ SiO2 during their evolution and emplacement.
A literature retrieval was performed for whole rock geochemical analyses of sedimentary, magmatic and metamorphic rocks in the catchment of River Thuringian Saale for the past 600 Ma. Considering availability and coincidence with paleontological an facies data the following indicators seem suitable to detect environmental and climatic changes: biogenic P for Paleoproductivity, STI Index for weathering intensity, Ni/Co-ratio for redox conditions, relative enrichments of Co, Ba and Rb versus crustal values for volcanic activity at varying differentiation. The Mg/Ca-ratio as proxy for salinity is applicable in evaporites. The binary plot Nb/Y versus Zr/TiO2 indicates a presently eroded volcanic level of the Bohemian Massif as catchment area for the Middle Bunter, whereas higly differentiated volcanics provided source material for Neoproterozoic greywackes. A positive Eu-anomaly is limited to the Lower Bunter and implies mafic source rocks perhaps formerly located in the Bohemian Massif.
| Organisation | Count |
|---|---|
| Bund | 171 |
| Kommune | 4 |
| Land | 1217 |
| Weitere | 1 |
| Wirtschaft | 3 |
| Wissenschaft | 108 |
| Zivilgesellschaft | 11 |
| Type | Count |
|---|---|
| Chemische Verbindung | 8 |
| Daten und Messstellen | 1262 |
| Förderprogramm | 141 |
| Gesetzestext | 13 |
| Hochwertiger Datensatz | 3 |
| Text | 5 |
| unbekannt | 18 |
| License | Count |
|---|---|
| Geschlossen | 808 |
| Offen | 637 |
| Unbekannt | 5 |
| Language | Count |
|---|---|
| Deutsch | 1346 |
| Englisch | 896 |
| Resource type | Count |
|---|---|
| Archiv | 257 |
| Datei | 45 |
| Dokument | 556 |
| Keine | 521 |
| Webseite | 509 |
| Topic | Count |
|---|---|
| Boden | 1317 |
| Lebewesen und Lebensräume | 1384 |
| Luft | 1340 |
| Mensch und Umwelt | 1450 |
| Wasser | 1353 |
| Weitere | 1438 |