Replication Data for: Cadmium isotope fractionation and neutron capture effects in lunar samples

Key Points: Geochemical Dichotomy of Lunar Soils: Early studies of Apollo lunar soils show a geochemical dichotomy, dominated by mare and highland lithologies with varying admixtures of material from the Procellarum KREEP Terrane. Cadmium (Cd): This study uses the volatile element cadmium to identify sources and origins responsible for mass dependent stable isotope fractionation and assess the effect of space weathering at the lunar surface. Cadmium concentrations and isotopic compositions are reported for samples from the Apollo 12, 16, and 17 missions. Thermal Neutron Capture: Thermal neutron capture by 113Cd, induced by galactic cosmic rays impacting the lunar surface, helps reconstruct the duration of exposure to space weathering. Cadmium stable isotope fractionation: Percent scale variations in Cd stable isotopes are observed, with e112/110Cd ranging from ~0 to +106 in mare soils, from +60 to +97 in highland soils. Orange glass 74220 exhibits an isotopically light enrichment (e112/110Cd = -27). The anorthosites have contrasting e112/110Cd (-107 vs. +47). Thermal neutron capture effects are larger in the old highland than the mare soils, possibly reflecting a compositional effect but mostly a longer exposure history to GCR. Implications for Lunar History and Material Origin: The findings of Cd isotopic compositions in immature KREEP-rich soils similar to that of the Bulk Silicate Earth suggest an origin for the KREEP material either as excavated material from the Copernicus crater or a vapor redistributed at the lunar surface. This comprehensive Cd isotope dataset provides a framework for future Cd isotope studies aiming to further our understanding on the distribution and origin of volatile elements in the Earth-Moon system

Analyses on Cibicidoides wuellerstorfi from ODP Hole 165-999A

For trace element analyses, single specimens of C. wuellerstorfi have been analyzed using femtosecond laser ablation inductively coupled plasma mass spectrometry (fs-LA-ICP131 MS) at the Geochemistry Laboratory at the Max Planck Institute for Chemistry. Na, Mg, and Sr of 142 specimens of C. wuellerstorfi have been measured at high-resolution on (up to) each of the final five chambers to eliminate possible inaccuracies that are likely to be caused by varying sample size. The fs-LA-ICP-MS analyses were performed on 25-μm diameter spots on each chamber with a pulse repetition rate of 15 Hz at low fluence (0.1-0.3 J/cm2). Calibration was performed with the microanalytical synthetic reference material MACS‐3 for carbonate and NIST612 for silica. Average values of all chambers analyzed in the same specimen were used for further analyses. Since foraminifers from different regions show particular offsets in the Mg/Ca composition of their shell, depending on region specific temperature ranges of ambient seawater, region-specific formulas are used. We have applied the formula Mg/Ca=0.82e^0.19*BWT of Tisserand et al. (2013) from samples collected from similar geographic situations to avoid offsets. The formula has been applied to calculate temperature variability of each analyzed chamber. The average value obtained from chamber-to-chamber temperature variability of each specimen has been applied as average temperature data of the entire test

GEOTRACES IC1 (BATS) contamination-prone trace element isotopes Cd, Fe, Pb, Zn, Cu, and Mo intercalibration

We report data on the isotopic composition of cadmium, copper, iron, lead, zinc, and molybdenum at the GEOTRACES IC1 BATS Atlantic intercalibration station. In general, the between lab and within-lab precisions are adequate to resolve global gradients and vertical gradients at this station for Cd, Fe, Pb, and Zn. Cd and Zn isotopes show clear variations in the upper water column and more subtle variations in the deep water; these variations are attributable, in part, to progressive mass fractionation of isotopes by Rayleigh distillation from biogenic uptake and/or adsorption. Fe isotope variability is attributed to heavier crustal dust and hydrothermal sources and light Fe from reducing sediments. Pb isotope variability results from temporal changes in anthropogenic source isotopic compositions and the relative contributions of U.S. and European Pb sources. Cu and Mo isotope variability is more subtle and close to analytical precision. Although the present situation is adequate for proceeding with GEOTRACES, it should be possible to improve the within-lab and between-lab precisions for some of these properties

Preface: Special Issue on Probing the Open Ocean With the Research Sailing Yacht Eugen Seibold for Climate Geochemistry

The 72‐foot sailing yacht Eugen Seibold is 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 CO 2 concentration 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. Plain Language Summary 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 (CO 2 ) from the atmosphere the more saturated they are with CO 2 (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 ES sailed in the eastern North Atlantic and will operate in the tropical eastern Pacific until 2025. Key Points 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., CO 2 ) in air and sea surface Proxy calibration of paleoclimate archives at high temporal and spatial resolution in relation to seawater and atmospheric parameter