Potassium ions (K+) are abundant in ore fluids of lode gold deposits, largely illustrated by pervasive potassic alteration and commonly expressed as K-feldspar and muscovite on both sides of individual gold lodes. However, their potential roles in gold mineralization remain elusive. Here, we present results from ab initio molecular dynamics simulation and geochemical modeling to address this question

Molybdenite has been established as a robust mineral for Re-Os isotope dating. However, higher-precision Re-Os molybdenite dating is necessary to accurately determine the absolute timing of metal mineralization and duration of ore-forming hydrothermal systems. To improve the precision and accuracy of molybdenite Re-Os dating, molybdenite from the Longmendian deposit—with its old age, heterogeneous

The mobility of rare earth elements (REE) in natural hydrothermal systems can be assessed using geochemical modeling, which requires reliable thermodynamic data of relevant aqueous species. In this study, we evaluate the controls of pH and temperature on La speciation and the role of hydroxyl complexes in REE transport at hydrothermal conditions. Batch-type hydrothermal solubility experiments were

Calcite plays a pivotal role in regulating the mobility and fate of zinc (Zn) in natural environments. Despite its significance, the mechanism of Zn sorption on calcite surfaces, particularly the transitional dynamics from surface adsorption to precipitation, remains unclear. This research studied the sorption behavior of Zn on calcite across a wide range of reaction times, pH values, and Zn concentrations

Highly siderophile element (HSE) contents of komatiites have been widely used to estimate the HSE composition of Earth’s mantle. However, the interpretation of existing komatiite data is controversial, with some authors arguing that the Archean deep mantle komatiite source was impoverished in HSE due to slow admixture of a late accretion component, while others invoke a melting process that would allow

Secular variations in the composition of the subcontinental lithospheric mantle (SCLM) are intimately controlled by multiple geological processes, including diverse melting mechanisms and complex metasomatic processes. We present comprehensive analyses of whole rock and mineral chemistry, along with Re-Os isotopic system of the Eastern Pyrenean orogenic mantle massifs, supported by quantitative modeling

Early pioneering studies of Apollo lunar soils revealed a geochemical dichotomy reflecting a dominance of mare and highland lithologies, with variable additions of Procellarum KREEP Terrane material. Here, we use the moderately volatile element cadmium to identify the sources and processes responsible for mass-dependent Cd stable isotope variations in the lunar regolith. In addition, capture of thermal

As an emerging contaminant, tungsten (W) displays unexpectedly high mobility in soil despite its extremely low solubility, challenging current scientific understanding. This paradox underscores the limited knowledge regarding the specific W species responsible for its high mobility. In this study, a series of field and incubation experiments were conducted across multiple soil types to investigate

Clumped isotopes of methane (CH4), specifically Δ13CH3D and Δ12CH2D2, provide additional information to constrain its sources and sink processes. These isotopes complement interpretations of CH4 provenance based on bulk isotopes. However, interpreting the origin of CH4 using isotopes becomes challenging when the isotopic signature is altered by post-generation processes. In this study, we measured

Globally, granites and rhyolites with SiO2 > 70 wt% show large Fe isotope variation (δ56Fe = −0.05 to +0.65 ‰) relative to less silicic igneous rocks in δ56Fe vs. SiO2 space. The upper bound of the data tends to show δ56Fe increase with increasing SiO2. Granitic magma differentiation can be invoked to explain magma compositional variation, including Fe isotope variation, but clearly cannot explain

The study of pristine chondrites provides insight into nebular processes that occurred prior to the accretion of small-sized parent bodies. The interchondrule matrix of the primitive chondrite Acfer 094 is characterized by the presence of submicron-sized anhydrous crystalline aggregates embedded in a silicate groundmass that is mostly amorphous. Transmission electron microscopy (TEM) and energy-dispersive

The release of fluids from magmas at crustal depths is an essential process for the formation of magmatic-hydrothermal ore deposits. However, assessing the extent of volatile loss by magma degassing or volatile gain by fluid fluxing from deeper magmas remains challenging. To develop a new tool to quantitatively track these processes, we experimentally determined the partition coefficients of Cl, Br

In this study, we experimentally investigate the diffusion of B in flux-rich (1.7 % Li2O, 2.5 % B2O3, 2.7 % P2O5 and 3.5 % F) pegmatite forming melts in order to assess the transport mechanisms of B in rare-element pegmatite deposits. Glasses were synthesized with either different B isotope compositions or with different B concentrations (up to 2.45 wt% B2O3). In order to explore the effect of water

The sodium-to-calcium ratio (Na/Ca) of biogenic CaCO3 has recently been introduced as a proxy for past seawater Ca2+ concentrations ([Ca2+sw]) as demonstrated by a positive correlation between seawater and shell Na/Ca with a minor influence of salinity. In the present study, we investigate the effect of carbonate chemistry on the Na/Ca proxy by conducting a set of experiments in which pH and the concentration

Type 7 chondrites, which record a higher degree of heating process than typical type 3 to type 6 chondrites, are characterized with textures and petrography of partial melting. Understanding the timing and cooling history of incipient melting event for type 7 chondrites could provide insights into the complex thermal process of the early solar system. Here, we studied two chondrites NWA 12272 and NWA

A comparison of the copper isotope composition of sedimentary rock strata spanning in age across the Great Oxidation Event (GOE) and that of pyrite, carbon, and native gold from the Mesoarchean Witwatersrand Basin reveal that an oxidative gradient triggered gold precipitation on biologic material, now present in the form of gold-rich carbon seams in the latter. Oxidative redox reactions are known to

The genesis of high-grade Fe-Ti-V oxide ores (up to >90 vol%) in layered intrusions remains highly debated. Here, on example of Hongge layered intrusion in China, we show that hydrothermal dissolution and precipitation of Fe-Ti-V oxides played a critical role in forming high-grade massive ore deposits as demonstrated by textural-compositional evidence and in-situ iron isotope data (δ56Fe), analyzed

Carbonated melts play a significant role in mobilizing lithophile and volatile elements in the Earth’s mantle and mantle metasomatism. However, there has been limited investigation into their potential for mobilizing chalcophile and siderophile elements(CSEs). In this study, we experimentally determine the sulfide liquid–carbonated melt partition coefficients of CSEs (DCSESul/C_melt) for a range of

Despite early hydrological studies of 234U/238U in groundwaters, their utilization as a paleoclimatic proxy in stalagmites has remained sporadic. This study explores uranium isotope ratios in 235 datings (230Th) from six stalagmites in Ejulve cave, northeastern Iberia, covering the last 260 ka. The observed 234U enrichment is attributed to selective leaching of 234U from damaged lattice sites, linked

Impact events were frequent in the early history of our Solar System, and the dynamics of planetary crust formation were, consequently, substantially different from the processes that dominate today. Mars, a planet with stagnant lid tectonics and a unique preservation of ancient surface terrains, provides an outstanding opportunity to investigate the early processes related to the formation and reshaping

Manganese oxide (MnOx) plays crucial roles in shaping various environmental and geochemistry processes, with their reactivity largely dependent on the structure of MnOx. Tunnel MnOx effectively hosts a substantial quantity of soil elements within its tunnel structure, exerting significant control over element turnover and pertinent geochemical processes, while the precise determinants regarding the

At slow to ultraslow-spreading ridges, tectonic mantle exhumation and magmatic processes accounts for heterogeneity in the lithosphere and drives deep hydrothermal circulation and fluids venting at the seafloor. However, the spatio-temporal evolution and the interplay between magmatic and hydrothermal processes during mantle exhumation, as well as their consequences for chemical exchange at mid-ocean

The NASA MESSENGER mission revealed that lavas on Mercury are enriched in sulfur (1.5–4 wt%) compared with other terrestrial planets (<0.1 wt%) due to high S solubility in silicate melt under its very low oxygen fugacity (ƒO2). However, the speciation of that S remains poorly constrained. In this study, we evaluate the role of pressure, temperature, and melt composition on S solubility and speciation

Understanding the relationships between the nitrogen (N) isotope ratios of early solar system planetesimals and terrestrial reservoirs is crucial for tracing the origin of volatiles on Earth. The Earth primarily grew from planetesimals and planetary embryos that accreted rapidly (within ∼1–2 Ma after CAIs) in the inner solar system, also known as the non-carbonaceous (NC) reservoir. Magmatic iron meteorites

Calcium-aluminum rich inclusions (CAIs) are the oldest condensates in the Solar System. Previous studies have revealed that moderately heavy and trace element isotope anomalies (e.g., Ti, Sr, Mo, and Nd) in CAIs record large nucleosynthetic isotope variations compared to bulk meteorites. Calcium is a major element in CAIs that has six stable isotopes with multiple nucleosynthetic origins. As such,

In this study we test the possibility that radiogenic 207Pb/206Pb ratios (207Pb*/206Pb*) in meteorites can be fractionated during partial dissolution, and explore the consequences of this fractionation for Pb-isotope chronology of meteorites. We report the results of experiments tailored to detect Pb-isotope fractionation, induced by partial dissolution through acid leaching, in plutonic angrite Northwest

The formation of a unique microstructure of minerals on the surface of airless bodies is attributed to space weathering. However, it is difficult to distinguish the contributions of meteorite impacts and solar wind to the modification of lunar soil, resulting in limited research on the space weathering mechanism of airless bodies. The thermochemical reactivity of troilite can be used to distinguish

A remnant of glacial seawater preserved in the pore fluids of sediment cores from the Maldives Inner Sea provided an opportunity to investigate the stable strontium isotopic composition (δ88/86Sr) of the ocean during the Last Glacial Maximum and explore the usefulness of δ88/86Sr as a tracer of early marine diagenesis. We used paired measurements of δ88/86Sr and radiogenic Sr isotope ratios (87Sr/86Sr)

The formation of polymers that can hold gene information and work as catalysts is a crucial step for the origin of life. The discovery of catalytic RNA (i.e., ribozyme) supports the hypothesis that RNA might have served these functions at the early stage of life on the Earth. Given this, the spontaneous formation of RNA monomers (i.e., ribonucleotides) and their polymerization on Hadean Earth are essential

The δ30Si and δ18O values of opal-A precipitated in plants (silica phytoliths) have been shown to be useful for paleoenvironmental reconstructions. Here, the effects of burning and partial dissolution of phytoliths on their isotopic compositions and dissolution behaviour were examined. Phytoliths were heated to 700 °C and then dissolution experiments were conducted in batch reactors under a range of

Cadmium (Cd)-bearing sphalerite (SP, ZnS) and smithsonite (SM, ZnCO3) particulate matter (PM) is deposited on soils near carbonate-hosted Zn ore deposits. Whether and how carbonate rocks such as limestone influence the mobility of Cd and Zn in soils is largely unknown. For this reason, we conducted a soil incubation experiment to investigate the chemical and mineralogical changes in soil–soil solution

The chemical evolution of the brines that filled the Dead Sea Basin during the final phase of the last interglacial and throughout the last glacial period is constructed from the temporal variations in the Na/Cl, Mg/Cl, Br/Cl, and Br/Mg ratios of soluble salts that were extracted from cores that were drilled at the modern Dead Sea floor and from sediments of the last glacial Lisan Fm. that are exposed

The short-lived 182Hf–182W system is widely used for constraining the chronology of the early Solar System, including the timing of the formation, thermal evolution, and differentiation of planetary bodies. Utilizing the full potential of the Hf–W system requires knowledge of the Hf/W ratio and W isotopic composition of primitive chondritic material. However, metal-silicate heterogeneity among chondritic

Constraining the origin of Earth’s building blocks requires knowledge of the chemical and isotopic characteristics of the source region(s) where these materials accreted. The siderophile elements Mo and Ru are well suited to investigating the mass-independent nucleosynthetic (i.e., “genetic”) signatures of material that contributed to the latter stages of Earth’s formation. Studies contrasting the

Understanding of the diversity and petrogenesis of achondrites is critical for deciphering magmatic processes and the early evolution of planets and asteroids. Here, we report the detailed petrologic, mineralogical, geochemical, and chronological features of the unbrecciated Vestan meteorite Northwest Africa (NWA) 8326. We found that NWA 8326 is composed of coarse-grained orthopyroxene (∼74 vol%),

Water significantly impacts the chemical evolution of the Earth’s crust, affecting environments from volcanic settings to hydrothermal systems. These fluids transport elements essential for geological processes, such as metal ore deposit formation. At high temperatures, as water transitions from liquid to vapor, its molecular structure changes, drastically reducing its capacity to dissolve solids and

In subduction systems, the forearc (FA) serpentinized mantle plays a key role as a reservoir for fluid-mobile elements, especially those prone to early mobilisation from the slab. FA serpentinites therefore provide an indication of the fluid characteristics that have been steamed out of the slab, and allow better quantification of elemental recycling and fluid flow. FA serpentinites outcropping along

Tropical small mountainous rivers (SMRs), characterized by extensive basin weathering, discharge high amounts of sediments and particulate terrestrial organic carbon (OCterr) into the ocean. Burial of OCterr in marine sediments is important for atmospheric CO2 sequestration, yet its rate and efficiency remain not fully understood. Previous studies indicated generally low burial rates and burial efficiencies

Fifteen elements, including most of the major elements, were quantified using neutron-induced prompt gamma-ray analysis for five Antarctic carbonaceous chondrites with CI affinities and seven with CM affinities. Common among the twelve meteorites is the depletion of volatile elements H and chlorine, showing a positive correlation and being depleted compared to non-Antarctic CI levels. This depletion

Beryllium isotopes (stable 9Be and cosmogenic meteoric 10Be) enter the oceans through distinct pathways – i.e., from the continents and the atmosphere respectively – and display non-conservative behaviour in seawater. This isotope system has served as a powerful tool for quantifying a variety of processes, including geomagnetism, sedimentation, continental input, and ocean circulation. However, processes

Silica solubility and molecular speciation in hydrothermal water vapor have been determined through quartz solubility experiments at 400–800 °C and 50–270 bar using a novel U-tube flow-through reactor system and theoretical calculations. The results demonstrate that silica concentrations are low in water vapor (mSi,tot = 0.11–4.56 mmol/kg or xSi,tot = 8.21 × 10−5–1.98 × 10−6 mol/mol) increase with

Polycrystalline diamond aggregates (PDAs) are small rocks composed mostly of diamond grains, but often containing also peridotitic, eclogitic and/or websteritic minerals as accessory phases. PDAs are formed rapidly in Earth’s mantle, and the diamonds preserve heterogeneity not often seen in monocrystalline diamond. Here, diamond grains from forty-three PDAs from the Venetia diamond mine (RSA) with

A series of hydrothermal diamond anvil cell experiments was conducted to constrain the equilibrium distribution of molecular H2 between H2O-saturated sodium aluminosilicate melts and H2O at elevated temperatures (600–800 °C) and pressures (317–1265 MPa). The distribution of H2 between the silicate liquid and the aqueous fluid was achieved through real-time monitoring of the H-H stretching vibration

Knowledge of the partial molar volumes of aqueous ions allows accurate calculation of the pressure dependence of equilibrium constants, solubility of minerals, etc., thus being useful for thermodynamic modeling of hydrothermal processes. This study analyzed methods to correlate and predict the values of the partial molar volumes at infinite dilution, V2o, for 1–1 electrolytes and singly charged ions

Anomalously high metal concentrations including iron enrichments are recorded in marine carbonates deposited during Ocean Anoxic Event 2 (OAE 2). These metal enrichments have been attributed to massive submarine eruptions during the formation of one or more large igneous provinces, the proposed trigger for OAE 2 (hydrothermal hypothesis), or to the release of metals from the reoxidation of formerly

Electron transfer between birnessite and organic compounds (OC) plays a dominant role in the coupling cycle of manganese (Mn) and carbon across diverse environmental settings. While previous studies have extensively investigated individual processes of interface Mn reduction, surface Mn2+ adsorption, and surface-to-interior electron transfer, the dynamic interplay among these reactions and the mechanisms

Understanding the behaviour of tantalum (Ta) in hydrothermal systems is pivotal for understanding its geochemical enrichment processes and economic extraction via hydrometallurgy. Yet, its behaviour in hydrothermal systems remains poorly characterised. This study investigates the coordination chemistry, speciation, and solubility of pentavalent Ta(V) in fluoride (F) − and chloride (Cl) −rich hydrothermal

The relationship between microbial activity and the supergene modification of ore systems has been a major subject of debate. Here, we present isotopic evidence of microbial-driven secondary copper mineralization in the active cementation zone of the Las Cruces deposit, a volcanogenic massive sulfide deposit located in Iberian Pyrite Belt, Spain. Copper isotopic data show that the lower isotopic ratios

Wildfires impact a large and increasing proportion of the Earth’s surface. With documented soil surface temperatures of up to ∼850 °C, wildfires may fundamentally alter the mineralogy and geochemistry of soils and regolith, more conventionally thought to be dominated by low temperature weathering processes. Here we use an experimental approach to test the effect of temperature on the formation of pyrogenic

Volcanic products returned from the Apollo missions over 50 years ago provide a unique perspective into the magmatic evolution of the Moon. However, questionsremain regarding the volatile loss, crystallization, and emplacement histories of lunar lavas. To address gaps in our understanding of the eruptive histories of lunar lavas, we investigate phase chemistry and 3D morphologies of low-titanium Apollo

Over the last decades, the chromium (Cr) stable isotope system (referred to as δ53Cr) has emerged as a proxy to reconstruct past oxygenation changes in Earth’s atmosphere and oceans. Although Cr is a promising paleoproxy, uncertainties remain as to the modern marine Cr cycle, and limited data are yet available in large swaths of the ocean, including the Atlantic Ocean. Here we present dissolved seawater

The molybdenum (Mo) isotope composition (defined as δ98Mo measured per mil relative to NIST-3134) of many modern arc systems and the upper continental crust is heavier than the mantle and most subducting slab lithologies. This observation has led to a model whereby fluids leaving the slab transfer isotopically heavy Mo preferentially to the mantle wedge, leaving the residual slab isotopically lighter

Ti- and Ba-rich tri-octahedral micas occur in fractionated basic igneous rocks, metasomatized mantle peridotites, metamorphosed pelites/carbonates, and hydrothermally altered mineral deposits. Electron microprobe analyses (EMP), with all iron reported as FeO, were widely used in the 1970/80s to interpret Ti and Ba substitution mechanisms, based on 22 O2– unit cell calculations, implying that cation

Anoxic marine sediments represent an important source of bioavailable iron (Fe) to the ocean. The highest sedimentary Fe fluxes are observed in open-marine oxygen minimum zones where anoxic bottom waters are in contact with ferruginous surface sediments. Here, sedimentary Fe release, transport and re-deposition (i.e., Fe shuttling) may generate a lateral pattern of sedimentary Fe enrichment and depletion