Environmental and biological factors influence the trace element composition (element / Ca) of planktic foraminifer shells. Consequently, the element / Ca measured in these shells (tests) are utilized as proxies to reconstruct past oceanic and climatic conditions. As single shell analyses are increasingly used in paleoceanographic research it is important to understand how proxy systematics change between species, individuals of the same species in a given population, and among chambers of a single individual during its life cycle. Here we present a time series of the chemical composition of planktic foraminifers retrieved using sediment traps between June 2014 and June 2015 at the northern part of the Gulf of Aqaba (aka Gulf of Eilat). Laser ablation ICP-MS element / Ca measurements were performed on single shells and chambers of Globigerinoides ruber albus and Turborotalita clarkei, collected monthly from five water depths (120, 220, 350, 450, and 570 m). Sediment trap samples were paired with corresponding data on water column hydrography and chemistry. Pooled means of measured element / Ca display species-specific and element-specific behavior, with generally higher values for T. clarkei phenotypes (“big” and “encrusted”) in comparison to G. ruber albus. Some element / Ca values measured in water column specimens, such as Al / Ca, vary significantly from core-top specimens. A unique finding is a prominent increase in element / Ca around March-April 2015, during maximum water column mixing, mostly apparent in T. clarkei and to a lesser extent in G. ruber albus. This spring element / Ca increase is observed in most measured elements and is further associated with an increase in inter-chamber variability (ICV). Inter-chamber element / Ca patterns show element enrichment/depletion in the most recently precipitated (final, F0) chamber in comparison to the older chambers (penultimate (F-1), antepenultimate (F-2), etc.). Element/Ca in F0 may also be less sensitive to surrounding environmental conditions. For example, the Mg / Ca of the F-1 and F-2 chambers of G. ruber albus display a positive relationship with mixed layer temperatures while F0 does not. To overcome this effect, we suggest using pooled means from non-F0 fractions as environmental records and paleo proxies. These results highlight the complexity of proxy systematics that arise from the variability in element / Ca measured among different species and between chambers, caused by ecological conditions and other processes in the water column including physical, chemical, and biological effects.

Speleothem trace element records can provide seasonal resolution climate reconstructions, but the interpretation can be challenging. Aragonite samples are understudied compared to calcite samples, despite that aragonite has 10x higher uranium concentrations and thus provide excellent dating precision. Here we present a high-resolution dataset of drip water trace elements (calcium, magnesium, strontium, barium, uranium) that are commonly affected by prior carbonate (calcite / aragonite) precipitation, a process often driven by effective rainfall. Our data suggest that prior calcite and aragonite precipitation can occur at the same drip site complicating the interpretation of strontium and uranium concentrations in aragonite speleothems. However, both processes can be distinguished with the “Sinclair test” through the trendline analysis of logarithmic relationships. Furthermore, our data show that aragonite speleothems slowly growing under relatively constant conditions are ideal to record variations in prior carbonate precipitation with its barium concentrations, independent from the prior carbonate precipitation mode. The Barium to Calcium ratio is an ideal proxy for studying rainfall-driven prior carbonate precipitation in slow growing aragonite speleothems, suggests a high-resolution geochemical study of drip water samples from Grotte de Piste, Morocco.

Mg/Ca is an independent proxy in paleoceanography to reconstruct past seawater temperature. Femtosecond Laser Ablation Inductively Coupled Plasma Mass Spectrometry (fs-LA-ICP-MS) was employed to determine the Mg/Ca composition of tests (shells) of the planktic foraminifer species Globigerinoides ruber albus (white chromotype) and G. ruber ruber (red/pink chromotype) sampled alive from the temperate to subtropical eastern North Atlantic with the research sailing yacht Eugen Seibold. Mg/Ca data are compared to (i) the measured in-situ temperature of ambient seawater, (ii) average mixed layer temperature, and (iii) sea surface temperature (SST). The pooled mean chamber Mg/Ca from each plankton tow site exhibits a positive relationship with SST. Two chamber-specific calibrations are derived, which are consistent with previous calibration equations for comparable paleo-archives. The results confirm fs-LA-ICP-MS as reliable method for determining Mg/Ca in G. ruber, and both the penultimate and antepenultimate chambers of adult specimens may provide comprehensible Mg/Ca temperatures of the surface ocean.

Over 50 years since its discovery and decades since its last recorded sighting in the modern ocean, Globorotalia cavernula has made another appearance: now in Subantarctic plankton tows south of Africa. This finding expands the known modern range of the species, which was commonly thought to be absent from the Atlantic sector of the Southern Ocean. Here, we use high -resolution microscopy and trace element analysis (fs-LA-ICP-MS) as a window into the ecology and habitat of this enigmatic species. Shell -averaged trace element ratios of G. cavernula are consistent with the cool - cold, well -oxygenated, open -ocean waters where it was collected (low Mg/Ca, Mn/Ca); and Sr/Ca is the least variable. Chamber -to -chamber trends are generally similar to other non-spinose species, but absolute values (e.g., Ba/Ca) can differ substantially. Combining our data with previous sightings suggests under-sampling/underreporting of G. cavernula in the modern/recent Southern Ocean, and possibly an expanded geographic range during the colder Pleistocene Epoch.

Abstract The Mg/Ca of marine calcareous Planktic Foraminifera (PF) shells is commonly used for sea surface temperature reconstructions. However, compared to open marine environments, hypersaline (>40) oligotrophic seas have been shown to accommodate PF with higher Mg/Ca and divergent temperature to Mg/Ca relationships. To investigate influencing factors of PF Mg uptake in hypersaline regions, we measured the Mg/Ca of two flux‐dominating PF species, Globigerinoides ruber albus and Turborotalita clarkei, derived from a monthly resolved time series of sediment traps in the Gulf of Aqaba, northern Red Sea as well as the corresponding temperature, salinity, and pH values. The PF exhibit elevated Mg/Ca which cannot be explained by post‐deposition or interstitial sediment diagenetic processes. G. ruber albus displays Mg/Ca trends that strongly follow seasonal mixed layer temperature changes. Conversely, T. clarkei Mg/Ca trends do not follow temperature but rather show significant Mg/Ca enrichment following mixing of the surface water column. We present a framework for incorporating elevated Mg/Ca into global Mg/Ca‐T calibrations for G. ruber albus and present a new Mg/Ca‐T calibration suitable for hypersaline marine environments.

This Geostandards and Geoanalytical Research Bibliographic Review 2022 presents an overview of a wide range of publications in 2022 focusing on the characterisation of new geoanalytical reference materials (RMs) as well as studies which published measurement results for established RMs. The development of highly accurate new methods and techniques leads to large new analytical data sets for RMs with improved accuracy and precision, which we present in this review.

Key Points Literature review of 7200 geoanalytical publications for the year 2020. 628 selected articles with summaries of target analytes, relevant reference materials and producers. Selected publications include data obtained by new analytical developments and improved analytical protocols for established RMs, and identifies recently developed RMs for specific scientific topics.

Three natural geological glasses (andesitic glass OJY-1, and rhyolitic obsidians OH-1 and OA-1) of specimen sizes 50150 g were characterised as reference materials for in situ microanalysis of major and trace elements, and Pb isotope ratios. Utilised techniques include isotope-dilution analyses by TIMS and MC-ICP-MS, bulk analyses by XRF, ICP-OES, ICPMS, and microanalysis (10-120 mu m spot size) by electron probe microanalyser, LA-ICP-MS and LA-MC-ICP-MS. Microanalyses (10-120 mu m) indicate that all three glasses are homogeneous with respect to fifty-four out of fifty-eight determined elements and Pb isotope ratios, except for Ni in OJY-1, and Cu, Zr and Ce in OH-1. The determination of reference values as well as their uncertainties at the 95% confidence level closely followed International Organization for Standardization (ISO) guidelines and the certification protocol of the International Association of Geoanalysts (IAG). These three glasses are fully natural without any subsequent heat treatment, and they represent useful additions to the widely distributed MPI-DING, USGS and CGSG reference glasses for microanalytical techniques such as electron probe microanalysis, mu-XRF, LA-ICP-MS and SIMS.

This GGR Bibliographic Review is a survey of approximately 5200 geoanalytical publications for the year 2021. Selected articles, numbering over 340, containing measurement results for relevant geological and environmental reference materials are listed with individual summaries of target analytes, relevant reference materials and producers. A brief summary of a selection of these publications is included that highlights notable developments in geoanalytical studies, newly developed or characterised RMs, and new datasets of established reference materials that have been re‐analysed using improved or state‐of‐the‐art measurement techniques.

Abstract Closure of the Central American Seaway (CAS) and hydrology of the Caribbean Sea triggered Northern Hemisphere Glaciation and played an important role in the Pliocene to modern‐day climate re‐establishing the deep and surface ocean currents. New data on Mn/Ca obtained with femtosecond laser ablation inductively coupled plasma mass spectrometry on well‐preserved tests of the epibenthic foraminifer Cibicidoides wuellerstorfi and infaunal C. mundulus contribute to the interpretation of paleoenvironmental conditions of the Caribbean Sea between 5.2 and 2.2 Ma (million years) across the closure of the CAS. Hydrothermal activity at the Lesser Antilles may be a primary source of Mn in the well‐oxygenated Plio‐Pleistocene Caribbean Sea. Incorporation of Mn in the benthic foraminifer shell carbonate is assumed to be affected by surface ocean nutrient cycling, and may hence be an indicator of paleoproductivity.

Hadean zircons, from the Jack Hills (Western Australia) and other localities, are currently the only window into the earliest terrestrial felsic crust, the formation of which remains enigmatic. Based upon new experimental results, generation of such early crust has been hypothesized to involve the partial melting of hydrated peridotite interacting with basaltic melt at low pressure (<10 km), but it has yet to be demonstrated that such liquids can indeed crystallize zircons comparable to Jack Hills zircon. We used thermodynamic and geochemical modeling to test this hypothesis. The predicted zircon saturation temperatures of <750 °C, together with the model zircon Th, U, Nb, Hf, Y, and rare earth element (REE) contents at 700 °C, δ18OVSMOW (Vienna standard mean ocean water) signatures, and co-crystallizing mineral assemblage were compared to those of the Jack Hills zircon. This comparison was favorable with respect to crystallization temperature, most trace-element contents, and mineral inclusions in zircon. The discrepancy in δ18OVSMOW signatures may be explained by hotter conditions of Hadean protocrust hydration. Our work supports the idea that felsic magma generation at shallow depths involving a primordial weathered ultramafic protocrust and local basaltic intrusions is indeed a viable mechanism for the formation of felsic crust on early Earth.

Different approaches for the determination of the 87Sr/86Sr isotope ratio of high-Rb glass are compared in this work to assess the suitability of minimally invasive approaches for applications on medieval stained glass (from the ancient Abbey of Stavelot in Belgium). It was found that pneumatic nebulization multicollector inductively coupled plasma–mass spectrometry (PN-MC-ICP-MS) after acid digestion and chromatographic isolation of the target analyte out of the sample matrix can still be seen as the preferred method for the high-precision isotopic analysis of Sr in glass with high Rb and rare-earth element (REE) concentrations. Alternatively, the use of laser ablation (LA) for sample introduction is a powerful technique for the direct analysis of solid samples. However, both the high Rb/Sr ratios in the samples of interest and the presence of REEs at sufficiently high concentrations lead to a large bias in LA-MC-ICP-MS, which cannot be corrected for, even by operating the MC-ICP-MS instrument at higher mass resolution and/or using mathematical corrections. It was demonstrated that LA tandem-ICP-MS (LA-ICP-MS/MS) using CH3F/He as the reaction gas to overcome spectral overlap in a mass-shift approach (chemical resolution) provides a viable alternative when (quasi) nondestructive analysis is required. This approach relies on the monitoring of Sr+ (m/z = 86, 87, and 88) ions as the corresponding SrF+ reaction product ions (m/z = 105, 106, and 107), thus avoiding the occurrence of spectral interference. Self-evidently, the isotope ratio precision attainable using sequential quadrupole-based ICP-MS instrumentation (0.3% RSD) was found to be significantly worse than that of high-precision MC-ICP-MS (0.03% RSD) with simultaneous detection, although it was still fit for the purpose of current applications. In addition to Sr isotopic analysis, the REE patterns and their potential influence on the Sr isotopic composition were evaluated by LA-ICP-MS.

The data set comprises of sea surface temperatures, salinity which were recorded from Akajima Island, Okinawa Prefecture, Japan during the year 2003 and 2004. The tidal heights data was generated using the software Tide Predictor for the Akajima Island. The Element/Ca analysis of larger benthic foraminifera Amphistegina lessonii was carried out by using Femto-second Laser Ablation Inductively Coupled Plasma-Mass Spectrometer (fs-LA-ICP-MS) technique at the Department of Climate Geochemistry, Max Planck Institute for Chemistry. The co-variation and correlation plots of Element/Ca with tidal heights, sea surface temperature and sea surface salinity are also provided.

Current theories suggest that the first continental crust on Earth, and possibly on other terrestrial planets, may have been produced early in their history by direct melting of hydrated peridotite. However, the conditions, mechanisms and necessary ingredients for this crustal formation remain elusive. To fill this gap, we conducted time-series experiments to investigate the reaction of serpentinite with variable proportions (from 0 to 87 wt%) of basaltic melt at temperatures of 1,250–1,300°C and pressures of 0.2–1.0 GPa (corresponding to lithostatic depths of ∼5–30 km). The experiments at 0.2 GPa reveal the formation of forsterite-rich olivine (Fo 90–94 ) and chromite coexisting with silica-rich liquids (57–71 wt% SiO 2 ). These melts share geochemical similarities with tonalite-trondhjemite-granodiorite rocks (TTG) identified in modern terrestrial oceanic mantle settings. By contrast, liquids formed at pressures of 1.0 GPa are poorer in silica (∼50 wt% SiO 2 ). Our results suggest a new mechanism for the formation of the embryonic continental crust via aqueous fluid-assisted partial melting of peridotite at relatively low pressures (∼0.2 GPa). We hypothesize that such a mechanism of felsic crust formation may have been widespread on the early Earth and, possibly on Mars as well, before the onset of modern plate tectonics and just after solidification of the first ultramafic-mafic magma ocean and alteration of this primitive protocrust by seawater at depths of less than 10 km.

The trace element chemistry of planktonic Foraminifera (PF) shells records the seawater composition and conditions of the marine environment in which they grow. Yet, long term in situ calibration and interspecies differences in proxy systematics are still poorly constrained, hampering the use of trace element distributions as environmental tracers of modern and past oceanic conditions. Here, we report element ratios using laser ablation mass spectrometry (LA-ICP-MS) in PF shells collected using monthly resolved sediment traps at various water column depths in the northern part of the Gulf of Aqaba (GOA) in 2014 and 2015. In particular, we focus on Calcium-normalized elemental abundances in different morphotypes of the two abundant species Globigerinoides ruber and Turborotalita clarkei . The results show that inter-chamber cation/Ca variability is lower in G. ruber relative to T. clarkei . In general, Mg/Ca in G. ruber display a positive correlation with temperature over time and depth. This general relationship does not exist in T. clarkei , which displays strong positive Mg/Ca perturbations in the subsurface water column, likely reflecting the impact of bottom sediment resuspension events during winter. B/Ca in G. ruber and T. clarkei displays a gradual first-order decrease over time that roughly corresponds with surface water p H patterns. By contrast, Sr/Ca remains constant around 1.5 mmol/mol between the chambers, species, and over time and different water depths. Al/Ca, Ti/Ca, Mn/Ca, and Fe/Ca co-vary, most likely reflecting the control of terrigenous end members, while B/Ca, Mg/Ca, and Na/Ca vary independently, each assumed to be controlled by different environmental processes. The results are evaluated in the context of oceanic properties and characteristic seawater trace element compositions, in order to improve their application as environmental tracers and paleo-proxies.

Amphistegina is a larger benthic foraminifer (LBF) commonly found within the modern coral reefs, and a major contributor to the CaCO 3 budget of shallow marine environments. As the family Amphisteginidae occurs through the Cenozoic, the potential as an archive for paleoclimate reconstruction is explored. We analyzed adult microspheric specimens of Amphistegina lessonii collected in September 2003, November 2003, January 2004, and March 2004, from ∼ 2 meters water depth in the coral reefs of Akajima, Okinawa, Japan. The intra ‐ test variability in trace elements of A. lessonii was investigated using femtosecond ‐ laser ablation ‐ inductively coupled plasma ‐ mass spectrometry (fs ‐ LA ‐ ICP ‐ MS) of the nine specimens from the outermost to innermost chamber. Tests of A. lessonii were analyzed for Mg/Ca, Na/Ca, and Sr/Ca along the septa to observe Test Size ‐ Lifespan relationships. The lifespan of a specimen of A. lessonii of 1200 µm in diameter is estimated at ∼ 3 months and ∼ 2 months for specimens 900 µm in size. Over the estimated lifespans, Mg/Ca of individual specimens of A. lessonii is highly variable and displays co ‐ variation with temperature and tidal height. High tides may increase sediment re-suspension and light attenuation thus leading to high Mg/Ca values within the calcareous shell of A. lessonii , analogous to similar mechanisms described for the symbiont-bearing planktic foraminifers

Abstract Amphistegina are common larger benthic foraminifer in coral reefs, with a nearly circumtropical distribution, and are major contributors to the CaCO3 budget of shallow marine environments. The family Amphisteginidae is dominant in Cenozoic carbonates. However, its potential as a proxy for paleoclimate reconstruction has not been completely explored. The intratest variability in trace elements of Amphistegina lessonii has been investigated using femtosecond‐laser ablation‐inductively coupled plasma‐mass spectrometry (fs‐LA‐ICP‐MS). We collected and analyzed adult specimens of A. lessonii in September 2003, November 2003, January 2004, and March 2004, from ∼2 m water depth in the coral reefs of Akajima, Okinawa, Japan. Tests of A. lessonii from these four collections were analyzed for Mg/Ca of the septa to observe Test Size‐Lifespan relationships. The lifespan of a specimen of A. lessonii of 1,200 µm in diameter is estimated at ∼3 and ∼2 months for specimens 900 µm in size. Over the estimated lifespans, Mg/Ca of individual specimens of A. lessonii is highly variable and displays co‐variation with temperature and tidal heights. Future projects may apply and further test this approach for the reconstruction of the tropical shallow marine paleoenvironments.