To better understand the rate and mechanism of olivine dissolution under acidic conditions, we exposed mm-sized ‘Norwegian olivine’ pebbles to hydrochloric, nitric and sulfuric acid at 65 °C and varying pH, for up to 50 days and monitored the evolution of Mg, Fe, and Si concentrations as well as pH. The evolution of the surface of the pebbles was examined ex-situ with Confocal Raman microscopy, Scanning

Methanethiol is one of the most abundant volatile organic sulfur compounds in natural aquatic systems and one of the main products of dimethylsulfoniopropionate decomposition. This study focuses on the kinetic parameters of the reaction of methanethiol and its deprotonated form, methanethiolate, with dissolved oxygen in aqueous solutions at various reactant concentrations, pH, and temperatures. The

Paddy soils located in coastal areas are readily exposed to seawater intrusion; however, the impact of salt ions on the adsorption of dissolved organic carbon (OCDissolved) at the soil–water interface and the transformation of solid-phase soil organic carbon (SOC) fractions remains quantitatively underexplored. Therefore, we investigated the dynamics of SOC, greenhouse gases (CH4 and CO2), and soil

In the last decade, several studies have reported enrichments of the heavy isotopes of moderately volatile elements in lunar mare basalts. However, the mechanisms controlling the isotope fractionation are still debated and may differ for elements with variable geochemical behaviour. Here, we present a new comprehensive dataset of mass-dependent copper isotope compositions (δ65Cu) of 30 mare basalts

Chemodiversity of soil organic matter (SOM) is vital for its formation and eco-functions. However, the link between SOM molecular diversity and its persistence across various ecosystems remains unclear. This study investigates the correlation between SOM molecular diversity and persistence in cropland, grassland, and forest ecosystems in western China. We analyzed soil samples and identified 42 parameters

Due to the lack of direct methods capable of determining the abundance of isotopologues containing multiple heavy isotopes within the crystal lattice, carbonates are typically reacted with phosphoric acid to produce CO2 analyte for clumped isotope analyses. This reaction is associated with fractionations of both bulk oxygen and clumped isotopes. Accurate knowledge of the effect of cation substitution

The weathering of basaltic rocks, especially on volcanic islands, plays a crucial role in global carbon cycling. Intense precipitation and warm atmospheric conditions accelerate weathering processes in these environments. While most estimates of weathering rates derive from river chemistry, soils and paleosols remain underexplored. In this study, we investigated the geochemistry of paleosols developed

The presence of HIMU (high-238U/204Pb) signatures in ocean island basalts has long been used to argue that ancient oceanic crust has been tectonically recycled into the mantle sources of plume-derived volcanic hotspots such as St. Helena or Mangaia. However, alternative hypotheses regarding the origins of HIMU signatures have also been put forward. This study addresses the origins of HIMU-like Pb isotopic

To reveal the fluid variations in the mantle sources of arc lavas from a fluid-dominated subduction zone and to further constrain its implications for global potassium (K) recycling, we present the K isotope compositions of thirty-two arc lavas from a 220 km arc-front to back arc transect across the Kamchatka Peninsula. Our results show that arc lavas from Eastern Volcanic Front (EVF, −0.48 ± 0.02 ‰

A significant population of primitive carbonaceous chondrites experienced short-duration heating, which is usually attributed to either impact or solar heating. Shock recovery experiments performed on carbonaceous chondrites have successfully reproduce the typical evolution in the petrographies and mineralogical compositions of natural samples. However, only few studies focused on the chemical and

The >23 km diameter, ∼207 Ma old Rochechouart impact structure is located in the NW part of the Paleozoic basement of the French Massif Central. Despite significant erosion, this impact structure preserves a heterogeneous suite of impactites, and the transition between the crater floor and the basement. Recent textural and geochronologic studies of U-Pb on zircon from impactites and basement lithologies

Determining the temperature of crustal anatexis associated with granitic magmatism is vital for understanding the petrogenesis of granites and the processes underlying crustal anatexis. During the partial melting of metasedimentary rocks, the breakdown of biotite at elevated temperatures can lead to the formation of peritectic garnet, which is typically rare or absent at lower temperatures when melting

An understanding of the differences between ungrouped, or anomalous, and normal carbonaceous chondrites could provide information on the population of parent bodies required to explain a chondrite group and on first solid accretion and evolution in the outer protoplanetary disk. The CR chondrites are key in this respect, as they display a unique formation history that distinguishes them from other

Despite the abundant occurrence and large variation in fluorine (F) in calcium carbonate minerals in geological settings, it remains poorly understood to what degree F can be incorporated into calcium carbonate minerals. Particularly, molecular-scale evidence for F incorporation modes in the calcite structure is lacking. In this study, we conducted coprecipitation experiments for F with calcium carbonate

The Ge elemental and isotopic composition of planetary materials holds essential clues on volatile element fractionation processes in nebular and planetary environments. To facilitate the interpretation of natural sample data we report the results of an experimental campaign that quantitatively assesses the elemental and isotopic fractionation of Ge during evaporation from graphite saturated Fe metal

Goethite is essential in controlling Zn mobility and behavior in surface environments and can strongly influence Zn isotope fractionation through adsorption processes. However, the influence of particle size of goethite on stable isotopic fractionation remains poorly understood. This research investigates the fractionation of Zn stable isotopes during adsorption onto nano- and micro-goethite, focusing

Understanding the behavior of trace elements such as Zr-Hf, REE, and Th-U during magmatic and hydrothermal processes is crucial for unraveling the evolution of rare-metal peralkaline granites. These elements play key roles in geochemical cycles, mineral formation, and economic mineral deposits. The Evisa intrusion, a rare-metal peralkaline granite, is an ideal setting to study such processes due to

Recycled pyroxenites are a key component of mantle heterogeneity, influencing magma generation and contributing to the radiogenic Os signature of oceanic basalts. However, natural examples of pyroxenites as proxies for crust-derived heterogeneities in the convective mantle are rare and recycling mechanisms remain debated. Here we report abundances of highly siderophile (HSE: Os, Ir, Pt, Pd, Re) and

Widely reported overdispersion of apatite (U-Th)/He ages has encouraged efforts to explore He diffusion kinetics and systematics in apatite. Studies such as continuous ramped heating (CRH) of apatite have revealed complex laboratory He behavior that is often correlated with abnormally old (U-Th)/He ages. Stemming from these studies is a hypothesis that diffusion sinks within apatite grains can reversibly

Here we report the in situ ion-microprobe analyses of the Li- and O-isotope compositions of enstatite, FeO-rich pyroxene, olivine, glass, and cristobalite grains from six chondrule-related objects from the Sahara 97103 EH3 chondrite. The O-isotope composition of the enstatite grains scattered around the intersection between the terrestrial fractionation and primitive chondrule minerals lines. Whereas

Refractory inclusions [Ca,Al-rich inclusions (CAIs) and amoeboid olivine aggregates (AOAs)] in unmetamorphosed chondrites (petrologic type ≤ 3.0) have typically uniform 16O-rich solar-like compositions. The origin of oxygen-isotope heterogeneity within individual refractory inclusions from weakly metamorphosed (petrologic type > 3.0) chondrites remains controversial. It may reflect (i) condensation

The use of clumped isotopes (Δ47) as a geothermometer in carbonates has become widespread in geosciences because carbonates are ubiquitous in the environment and this technique also constrains the precipitating fluid δ18O composition. However, in some contexts, Δ47 values cannot be used as a geothermometer. Instead, they provide insights into processes affecting the isotopic composition of CO2 and

Subduction zones act as pivotal engines for global element cycling. Titanium (Ti) isotopes, exhibiting mass-dependent fractionation, emerge as a robust geochemical tracer for deciphering complex processes in these dynamic settings. However, the behavior of Ti and its isotopes during metamorphic dehydration and partial melting of deeply subducted continental lithosphere remains poorly constrained. This

Partition coefficients for Cu, Au and Mo between an aqueous fluid (∼ 4–16 wt% NaCl eq.) and felsic melts, were determined experimentally to better constrain the enrichment of these metals during magmatic fluid exsolution in porphyry copper systems. The experiments were conducted with a variety of melt and fluid compositions at 850 ℃, 200 MPa and an oxygen fugacity approximating that of the Ni-NiO buffer

Hydrogen (H) isotope fractionation during the dehydration of H-bearing minerals is crucial for tracing the subduction processes. Previous studies have shown that H isotope fractionation between brucite and water is highly sensitive to the change of pressure. However, the detailed behaviors of H isotopes at high temperatures and high pressures remain poorly understood. In this study, we investigate

The genesis and compositional diversity of granites are primarily controlled by multiple processes, including partial melting and magma differentiation. However, discriminating the individual effects of processes such as partial melting, fractional crystallization, and fluid-magma interaction on the evolution of granitic magma remains challenging. Barium isotopes serve as a potentially powerful tracer

Microbial iron and manganese respiration processes have been observed in deep methanic sediments of lacustrine and marine environments, challenging the “classical” model of microbial respiration in aquatic systems. Nonetheless, assessments of the type and relative role of these respiration processes in the methanic zone are lacking. Here, we quantify both the thermodynamic and the kinetic controls

We present electron probe micro analyses (EPMA), and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) mineral chemistry and B-isotope data for magmatic and hydrothermal Li-Fe micas of the granite-related Sn-W-Li Sadisdorf greisen system in the Erzgebirge, Germany. These mineral-specific data were combined with novel in-situ mica and whole-rock powder-pellet LA-ICP multi-collector

Sulfur isotopic values (δ34S) of pyrite and organic matter (OM) in sediments are widely used for the reconstruction of the sulfur and oxygen cycles as well as pathways of OM preservation. Currently, significant uncertainties persist regarding the mechanism by which sulfur is partitioned between pyrite and OM and its effect on the δ34S record of rocks. Here, we present experimental analysis of iron

Studies of shock metamorphic effects in apatite and merrillite in nine ordinary chondrites (OCs) of petrologic types 3.5–6 and shock metamorphic stages S1–S5 using transmission electron microscopy (TEM) reveal a correlation between the extent of brittle deformation in phosphates and the shock metamorphic stage of six host meteorites. No correlation is observed in thermally annealed and partially melted

Ester-linked membrane-spanning lipids, such as iso-diabolic acid (iso-DA), are known components of some bacterial cell membranes, e.g., several species of Acidobacteria. However, the underlying biosynthetic mechanism and the physiological function of iso-DA remain elusive. In this study, we identified ester-linked membrane-spanning lipids, iso-diabolic-based tetraesters (iso-DTs) and their derivatives

Pyrite from hydrothermal deposits often exhibits oscillatory zoning, controlling the distribution of trace elements, like As and Au. The origin of this zonal pattern has long been debated between episodic fluid changes and local chemical disequilibrium. Our study of an epithermal Pb-Zn deposit reveals arsenic oscillatory zonation in monocrystalline pyrite grains. Guided by the results of examination

The redox capacities of soil DOM regulate the oxidation–reduction reactions by accepting or donating electrons, which influences a variety of critical redox processes such as greenhouse gas emissions and the (bio)geochemical cycle of contaminants. The composition and reactivity of DOM components vary with their molecular weight (MW), and, therefore, the redox capacities of soil DOM are expected to

Subseafloor hydrothermal systems exert a strong control on the chemical composition of the ocean. Likewise, the chemical composition of the ocean impacts the chemical and physical reactions that happen during hydrothermal circulation, although this has been less well considered. We present a 2D model of basalt alteration under hydrothermal conditions, exploring how changes in major seawater ion concentration

Zirconium (Zr) isotopes are an emerging tool to study igneous processes. However, Zr isotope fractionation mechanisms are debated, especially regarding the relative roles of kinetic and equilibrium effects. Here, we report high-precision in-situ Zr isotope (δ94Zr) measurements in zircons from granitoids with ages of 3.4 to 2.5 Ga. The δ94Zr values in all magmatic zircons range from −0.63 to + 0.41 ‰

Ferromanganese concretions in the shelf sea regions, such as the Baltic Sea, are of significant interest due to their geochemical properties, economic resource potential, and roles in benthic ecosystems. This study analyses the authigenic and detrital mineral phases and their provenance in the Baltic Sea concretions, as well as their formation mechanisms and diagenetic evolution. These concretions

Water plays a pivotal role in the differentiation of continental crust and the formation of granitic magmas. However, it is still hotly debated how to identify fluid regimes during crustal anatexis. Molybdenum (Mo) isotopes have shown the potential to trace fluid activity during magmatic and metamorphic processes and thus are a valuable tool to identify the presence of free fluid during crustal anatexis

Magmatism in deep continental arcs is crucial for understanding the formation of andesitic continental crust. Garnet, pyroxene and amphibole are typical major mafic phases in deep arcs, with garnet potentially causing noticeable variations in stable isotopes of major elements such as Ca (δ44/40Ca). The upper continental crust (UCC) shows low δ44/40Ca value (0.70 ± 0.02 ‰, 2SE) relative to oceanic crust

Understanding the structure and transport properties of supercritical fluids is crucial for gaining insights into their behavior in subduction zones. While previous research has provided an understanding of the properties of supercritical fluids derived from felsic melts, our knowledge regarding supercritical fluids formed from ultramafic melts in deep subduction zones remains limited. In this study

Benthic fluxes are critical pathways for constituent exchanges and biogeochemical interactions across sediment–water interface. To comprehensively evaluate the modulation of bioturbation on the benthic fluxes of nutrients, we present a novel inverse geochemical modelling framework in near-surface sediments of Lake Taihu, a highly eutrophic freshwater lake in eastern China. This approach incorporates

Sediments/sedimentary rocks are a major sink of atmospheric N2, which is mainly fixed into diazotrophic biomass and recycled into other organic matters or diagenetically transferred (in the form of NH4+) into the crystal structures of phyllosilicate minerals in sediments. Driven by tectonic activities, sedimentary rocks may experience various degrees of metamorphism with some eventually being melted

We quantify the evaporation of moderately volatile chalcophile elements (MVCEs, here Cu, Zn, Ge, As, Ag, Cd, In, and Pb) from silicate melts. Our approach is to subject MVCE-bearing silicate melt to variable temperature (1480–1773 K), fO2 (10−9 to atmospheric) and fS2 (0 or 10−3 to 10−2), and duration (5 min to 24 h) using a gas-mixing furnace where evaporation can occur. Chemical analyses are completed

The isotopic composition of tooth and bone has long been exploited in ecological, environmental, and archaeological studies. Increasingly, hydrogen and oxygen isotopes in collagen are used as tracers of environment and diet. However, the isotopic relationship between hydrogen and oxygen in collagen and oxygen in tooth enamel is poorly described. A new investigation of varied wild large herbivores shows

During the world’s first nuclear explosion, in 1945, glassy melts called “trinitites”, mostly derived from the sands at the surface of the test site, formed and were deposited at or near the hypocenter. The processes of formation of this fallout remain unclear. Here, we show how the oxygen and silicon isotopic compositions of three trinitites allow to refine their formation scenario. The three samples

The Yangtze River Estuary and the adjacent inner shelf are significant areas for both the burial and degradation of terrestrial organic matter (OM). However, the impact of hydrodynamics on the degradation of different types of organic compound classes has not been fully elucidated. This study measured dual carbon isotopes (δ13C, Δ14C) of organic compound classes [total hydrolysable amino acids (THAAs)

The origin of slab components in arc lavas remains controversial with proposed sources including direct sediment melts, sediment-mantle mélanges, or crustal fluids. Stable isotope distributions of fluid-borne metals and those immobile in subduction components have the potential to trace the respective contribution of these components if placed into the context of additional magmatic differentiation

The Sr and Ca isotope composition, along with trace element content in fossil teeth, provides valuable insights into biogenic and diagenetic processes. Identifying pristine biological signals is crucial for reconstructing the diet and trophic levels of extinct taxa. We present novel geochemical data from Tyrannosauridae and Ceratopsidae teeth of the Late Cretaceous, using radiogenic Sr (87Sr/86Sr)

Constraining mid-ocean ridge magmatic processes is crucial for understanding the geochemical evolution of magmas traversing the oceanic crust. A crucial archive for investigating these magmatic processes is the chemical composition of lower oceanic crust. This study presents Zn isotope data for primitive to highly evolved cumulates from the Mid-Atlantic Ridge (Kane) and the Southwest Indian Ridge (IODP

Coprecipitation of phosphate in calcium carbonate minerals is a ubiquitous geochemical phenomenon in marine sedimentation and cave stalagmite formation, however, it is not clear whether phosphate is incorporated into the calcite structure. In this research, we applied solid-state nuclear magnetic resonance (NMR) spectroscopy to analyze P speciation during coprecipitation with calcite. The 31P NMR results

Ages of angrites, a diverse and rapidly growing group of differentiated meteorites, are important for understanding the history of their parent body, which is proposed to be an archetypal first-generation planetesimal. Angrites also commonly serve as a time reference in the early Solar System chronology. Pb-isotopic ages of angrites can be determined with high precision, and the isotopic composition

The incorporation of trace and minor elements into coral skeletons and the underlying chemical and biological processes that govern them, are highly relevant for understanding coral biomineralization and for accurate reconstructions of past ocean conditions. In the present experimental study, that follows our previous publications (Ram and Erez, 2021, 2023), we determined the partition of six cations

Porewater dissolved organic matter (DOM) in lake sediments is an important contributor to the global carbon cycle. The composition and structures of porewater DOM typically vary with depth, yet the variations in high-resolution depth intervals and the controlling biogeochemical processes are not well understood. Here we performed comprehensive, high-resolution (1 cm interval) characterization of sediment

Thallium (Tl) isotopes are a robust tracer of ancient ocean oxygenation through their link to the burial flux of deep-sea manganese oxide minerals. Yet, the details of Tl geochemistry at the continental margin remain largely unexplored, hindering quantitative application of the palaeoredox proxy. To develop our understanding of Tl diagenesis, phase dynamics, and mass transfer at the continent-ocean

This study investigates hydrogeochemical processes, reaction rates and the effect of spatial scales in mountain carbonate watersheds. A reactive-transport model was deployed to capture the concentration-discharge relations (C-Q relations) of major solute species measured in the river waters of two critical zone observatories located in the south of France (southern Alps and Ardèche). The specific control

Continental flood basalt (CFB) provinces, defined by the rapid emplacement of large volumes of mafic lava, represent some of the most significant large-scale magmatic events in Earth’s geological record. Gaining insight into the origin and evolution of fluid systems within these settings is critical for understanding the geodynamic architecture of large igneous provinces (LIPs) and accompanying mineralisation

Chromitites in ophiolites are recognized for their high concentrations of highly siderophile elements (HSE), notably IPGE (Os, Ir and Ru). However, the effects of this enrichment on ophiolitic rocks and mantle heterogeneity remain poorly understood and to address this issue, we investigated chromitites from the Pozantı-Karsantı and Kızıldağ ophiolites in Türkiye. The results reveal HSE enrichment,

Pyrite-marcasite assemblages, formed at steep physicochemical gradients in submarine hydrothermal systems, serve as valuable records of fluid evolution and ore-forming processes. However, gaps remain in our understanding of the detailed pathways of pyrite-marcasite formation and their dynamics of trace element enrichment in seafloor massive sulfide deposits. Here, we utilize in-situ trace element and

The high-latitude oceans are regions of high mercury (Hg) bioaccumulation, especially in the form of methylmercury (MeHg), which is of great concern in terms of human and ecosystem health. In the high-latitude North Atlantic (60-80°N), the deep water entrains the Hg-enriched Arctic water southwards, consequently influencing global Hg cycling. Whilst Hg removal has been proposed en route from the Arctic

Dissolved organic matter (DOM)-modified organic and inorganic colloids are known to enhance the mobilization and transport of different trace elements in aquatic environments. Occurrences of selenium (Se) in natural waters often positively correlate with DOM under diverse environmental conditions, suggesting that DOM may enhance Se mobilization at the soil/sediment–water interface. Despite its importance