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Funding: This study was supported by urgency funding from the U.K.’s Science and Technology Facilities Council (STFC) as part of the project “Curation and Preliminary Examination of the Winchcombe Carbonaceous Chondrite Fall.” Additional work was funded by STFC through grants ST/N000846/1, ST/T002328/1, ST/T506096/1, and ST/W001128/1 (to L.D., M.R.L., and L.J.Ha.); ST/V000675/1 (to K.H.J. and R.H.J.); ST/P005225/1 (to R.T.); ST/S000348/1 (to M.V.G., P.J.W., and M.J.B.); ST/R00143X/1 (to J.B. and L.J.Hi.); ST/S000615/1 (to G.S.C.); ST/V000799/1 (to P.G.); and ST/V000888/1 (to T.E.). A.J.K. and H.C.B. acknowledge funding support from UK Research and Innovation (UKRI) grant MR/T020261/1. P.L.C. acknowledges funding support from UKRI grant MR/S03465X/1. K.H.J. acknowledges funding support from the Royal Society, grant URF\R\201009. L.J.Ha. and M.R.L. acknowledge funding from Natural Environment Research Council (NERC) National Environmental Isotope Facility (NEIF) grant no. 2406.0321. L.D., M.R.L., and L.J.Ha. acknowledge COVID-19 funding support from the University of Glasgow, UK. D.V. was supported in part by NASA cooperative agreement 80NSSC21M0073. P.P. and I.Sy. acknowledge funding from the VEGA agency, project no.1/0421/20. A.J.T.J. acknowledges support from the European Union and the State of Hungary, cofinanced by the European Regional Development Fund in the project of GINOP-2.3.2-15-2016-00009 “ICER.” P.M.S. acknowledges support from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 945298. FRIPON was initiated by funding from ANR (grant N.13-BS05-0009-03), carried out by the Paris Observatory, Muséum National d’Histoire Naturelle, Paris-Saclay University, and Institut Pythéas (LAM-CEREGE). FRIPON data are hosted and processed at Institut Pythéas SIP (Service Informatique Pythéas). The Desert Fireball Network team and Global Fireball Observatory are funded by the Australian Research Council (DP200102073). Direct links between carbonaceous chondrites and their parent bodies in the solar system are rare. The Winchcombe meteorite is the most accurately recorded carbonaceous chondrite fall. Its pre-atmospheric orbit and cosmic-ray exposure age confirm that it arrived on Earth shortly after ejection from a primitive asteroid. Recovered only hours after falling, the composition of the Winchcombe meteorite is largely unmodified by the terrestrial environment. It contains abundant hydrated silicates formed during fluid-rock reactions, and carbon- and nitrogen-bearing organic matter including soluble protein amino acids. The near-pristine hydrogen isotopic composition of the Winchcombe meteorite is comparable to the terrestrial hydrosphere, providing further evidence that volatile-rich carbonaceous asteroids played an important role in the origin of Earth's water. Publisher PDF

The shells of calcitic arthropod Amphibalanus improvisus; aragonitic bivalves Cerastoderma glaucum, Limecola balthica, and Mya arenaria; and bimineralic bivalve Mytilus trossulus were collected in the brackish waters of the southern Baltic Sea in order to study patterns of bulk elemental concentration (Ca, Na, Sr, Mg, Ba, Mn, Cu, Pb, V, Y, U and Cd) in shells composed of different crystal lattices (calcite and aragonite). The factors controlling the elemental composition of shells are discussed in the context of crystal lattice properties, size classes of organisms and potential environmental differences between locations. Clams that precipitate fully aragonitic shells have a clear predominance of Sr over Mg in shells, contrary to predominant accumulation of Mg over Sr in calcitic shells of barnacles. However, the barnacle calcite shell contains higher Sr concentration than bivalve aragonite. The elemental variability between size-grouped shells is different for each studied species, and the elemental concentrations tend to be lower in the large size classes compared to the smaller size classes. Biological differences between and within species, such as growth rate, feeding strategy (including feeding rate and assimilation efficiency or composition) and contribution of organic material, seem to be important factors determining the elemental accumulation in shells. Because specimens used in this study were obtained from different sampling sites within the gulf, the impact of location-specific environmental factors, such as sediment type, cannot be excluded.

In this study, the concentrations of 12 metals: Ca, Na, Sr, Mg, Ba, Mn, Cu, Pb, V, Y, U and Cd in shells of bivalve molluscs (aragonitic: Cerastoderma glaucum, Mya arenaria and Limecola balthica and bimineralic: Mytilus trossulus) and arthropods (calcitic: Amphibalanus improvisus) were obtained. The main goal was to determine the incorporation patterns of shells built with different calcium carbonate polymorphs. The role of potential biological control on the shell chemistry was assessed by comparing the concentrations of trace elements between younger and older individuals (different size classes). The potential impact of environmental factors on the observed elemental concentrations in the studied shells is discussed. Specimens were collected from brackish waters of the Baltic Sea (the Gulf of Gdansk). For every species, 40 individuals (ten in each size class) were selected. Pre-cleaned shells were analysed by ICP-OES and ICP-MS to determine the concentrations of metals. The distributions of elements both differ between species and exhibit high intraspecific variability. Calcitic shells preferentially incorporated Mg > Sr > Na, aragonitic shells incorporated Na > Sr > Mg, and bimineralic shells accumulated Na approximately two times more intensively, than Mg and Sr which remained at similar levels. Among all species, the calcitic shells of A. improvisus most effectively concentrated the majority of the studied elements, especially Mg > Mn > Ba, which was contrary to the shells of aragonitic molluscs that contained the lowest levels of trace elements. The size-dependent distributions of elements in shells did not exhibit a consistent pattern. The highest significant differences were found for the bimineralic shells of M. trossulus, while the smallest were found for aragonitic shells; if any variability occurred, it was observed in heavy metals (Pb, Cd). Our results indicate that elemental variability, especially that of Mg and Sr, is dominated by the properties of the crystal lattice. The inconsistent variability of trace element concentrations between species and within single populations supports the important role of species-specific biological control of the biomineralization process and indicates that environmental factors have a significant influence on the incorporation of trace elements into the shells.

Stable isotope compositions can potentially be used to trace atmospheric Cd inputs to the surface ocean and anthropogenic Cd emissions to the atmosphere. Both of these applications may provide valuable insights into the effects of anthropogenic activities on the cycling of Cd in the environment. However, a lack of constraints for the Cd isotope compositions of atmospheric aerosols is currently hindering such studies. Here we present stable Cd isotope data for aerosols collected over the Tropical Atlantic Ocean. The samples feature variable proportions of mineral dust-derived and anthropogenic Cd, yet exhibit similar isotope compositions, thus negating the distinction of these Cd sources by using isotopic signatures in this region. Isotopic variability between these two atmospheric Cd sources may be identified in other areas, and thus warrants further investigation. Regardless, these data provide important initial constraints on the isotope composition of atmospheric Cd inputs to the ocean.

Anthropogenic emissions completely overwhelmed natural marine lead (Pb) sources during the past century, predominantly due to leaded petrol usage. Here, based on Pb isotope measurements, we reassess the importance of natural and anthropogenic Pb sources to the tropical North Atlantic following the nearly complete global cessation of leaded petrol use. Significant proportions of up to 30–50% of natural Pb, derived from mineral dust, are observed in Atlantic surface waters, reflecting the success of the global effort to reduce anthropogenic Pb emissions. The observation of mineral dust derived Pb in surface waters is governed by the elevated atmospheric mineral dust concentration of the North African dust plume and the dominance of dry deposition for the atmospheric aerosol flux to surface waters. Given these specific regional conditions, emissions from anthropogenic activities will remain the dominant global marine Pb source, even in the absence of leaded petrol combustion., Anthropogenic lead (Pb) has overwhelmed natural Pb sources for over a century, yet the phasing out of leaded petrol in the early 2000s has renewed hope. Here, Bridgestock et al. use Pd isotopes to reassess the origins of Pd deposited in the tropical North Atlantic and reveal a significant natural source.

This is a digital supplement to: Humphreys-Williams, E. R., and Zahirovic, S., 2021, Carbonatites and Global Tectonics, Elements. &nbsp

This is a digital supplement to: Humphreys-Williams, E. R., and Zahirovic, S., 2021, Carbonatites and Global Tectonics, Elements. Version 2: Fixed some plotting artefacts in the animations.