Sulfur Isotope Research Articles

Establishing a comprehensive host-parasite stable isotope database to unravel trophic relationships

Over the past decades, stable isotopes have been infrequently used to characterise host-parasite trophic relationships. This is because we have not yet identified consistent patterns in stable isotope values between parasites and their host tissues across species, which are crucial for understanding host-parasite dynamics. To address this, we initiated a worldwide collaboration to establish a unique database of stable isotope values of novel host-parasite pairs, effectively doubling the existing data in published literature. This database includes nitrogen, carbon, and sulphur stable isotope values. We present 3213 stable isotope data entries, representing 586 previously unpublished host-parasite pairs. Additionally, while existing literature was particularly limited in sulphur isotope values, we tripled information on this crucial element. By publishing unreported host-parasite pairs from previously unsampled areas of the world and using appropriate host tissues, our dataset stands unparalleled. We anticipate that end-users will utilise our database to uncover generalisable patterns, deepening our understanding of the complexities of parasite-host relationships and driving future research efforts in stable isotope parasitology.

Sulfur isotope (δ34S) stratigraphy of evaporites: Application to the UK Triassic

Sulfur isotope (δ34S) stratigraphy of evaporites: Application to the UK Triassic

Terrestrial pyrite oxidation point to carbon cycle: Insights from sulfur and oxygen isotope composition in rivers

Terrestrial pyrite oxidation point to carbon cycle: Insights from sulfur and oxygen isotope composition in rivers

Spatiotemporal fluctuations of pyrite sulfur isotope with pyrite morphology during the Ediacaran-Cambrian transition

Spatiotemporal fluctuations of pyrite sulfur isotope with pyrite morphology during the Ediacaran-Cambrian transition

Molybdenite Re-Os geochronology, pyrite in-situ trace element and sulfur isotope analysis of the Haigou gold deposit, Northeast China: Implications for the genesis of an intrusion-related lode gold deposit

Molybdenite Re-Os geochronology, pyrite in-situ trace element and sulfur isotope analysis of the Haigou gold deposit, Northeast China: Implications for the genesis of an intrusion-related lode gold deposit

The Evolution of Atmospheric Composition: Why Earth is a Habitable Planet

The long term evolution of Earth’s atmosphere and climate has been an active topic of investigation for at least the last 60 years. My own participation in this investigation goes back more than 45 years, and this monograph relates that story from my personal perspective. One major thread concerns the rise of atmospheric O2 from near-zero levels initially to the 21 percent mixing ratio that we observe today. Photochemical models developed by me and my students, along with some close colleagues, have helped to better constrain the prebiotic O2 concentration and to interpret the constraints imposed by the record of mass independent fractionation of sulfur isotopes. Most geochemists now agree that a so called Great Oxidation Event (GOE) occurred between 2.4 and 2.2 Ga and that the atmosphere has been O2-rich since that time. However, the exact level of O2 during the ensuing Proterozoic Era remains controversial, as do the timing and magnitude of subsequent O2 increases. The corresponding development of the ozone layer is also of interest because of its moderating influence on surface solar UV fluxes and their effect on biological evolution. This can also be studied with photochemical models. A second thread concerns the gradual decline in atmospheric CO2 in response to slowly increasing solar luminosity. The early Earth would have been frozen had the atmosphere not contained high concentrations of greenhouse gases, most importantly CO2. A negative feedback in the carbonate-silicate cycle that controls CO2 over long time scales has ensured that Earth’s surface has remained habitable during most of Earth’s history, despite occasional forays into Snowball Earth conditions. Evidence from palaeosols provides support for this hypothesis. CH4 is an additional greenhouse gas that may have supplemented surface warming prior to the GOE. The increase in O2 at that time may have caused CH4 to decrease, possibly triggering the Huronian glaciations. The same feedback mechanism that controls long term CO2 evolution on Earth could operate on Earth-like planets orbiting other stars, increasing the probability that some of them may harbour life. Large direct imaging space telescopes currently under development may eventually allow us to test this hypothesis and to learn whether we have company in this part of our galaxy.

Microscale iron and sulphur isotopic compositions reveal pyritization pathways during early diagenesis

Sedimentary pyrite iron and sulphur isotope compositions (δ56FePYR, δ34SPYR, Δ33SPYR) are commonly used to reconstruct global ocean properties and the evolving oxidation state of Earth’s surface, motivating exploration of impacts of diagenesis on pyrite-based proxies. Along with auxiliary petrographic and porewater data, we present coupled microscale δ56FePYR-δ34SPYR-Δ33SPYR in accumulating sediments on the oxic margin of the Black Sea. The coevolution of microscale δ56FePYR-δ34SPYR-Δ33SPYR distributions provides insight into porewater S species production, consumption, and buildup on pyritization pathways. “Early” pyrite is characterized by low δ56FePYR and δ34SPYR values consistent with microbially-mediated iron and sulphate reduction and iron (oxyhydr)oxide sulphidization at low sulphide-to-iron ratios. In contrast, “sulphidic zone” pyrite displays distinct late-stage morphologies and higher δ56FePYR and δ34SPYR, which reflect sulphide accumulation at the sulphate-methane transition zone and direct sulphidization of residual iron phases. We propose that coupled δ56FePYR-δ34SPYR-Δ33SPYR distributions constrain pyritization pathways and microbial and physico-chemical aspects of the depositional environment.

Ayakhta gold-quartz deposit (Yenisei Ridge): formation conditions and source of fluids

Relevance. The need to establish the parameters of ore-bearing fluids of the Ayakhta gold deposit, one of the standard and large objects in the Yenisei Ridge. The data obtained can be used to develop a holistic model of gold mineralization in the region. Aim. To determine the physicochemical conditions for the formation of quartz vein zones and ore-bearing fluids source. Methods. We analyzed the ore minerals composition by micro-X-ray spectral analysis, determined the temperatures of phase transitions in fluid inclusions using the microthermometry method, determined the individual fluid inclusions composition by Raman spectroscopy. The fluid bulk composition was analyzed by gas chromatography-mass spectrometry (GC-MS). To establish the source of the fluid, we used isotopes of sulfur (δ34S) sulfides and carbon dioxide (δ13C) in fluid inclusions in quartz. Results and conclusions. We established that the gold-quartz vein zones formation occurred under medium temperature conditions (121–424°C) with significant pressure fluctuations (0.5–1.5 kbar). The fluid salinity was moderate (up to 25.5 wt %, NaCl-eq.). Using the GC-MS method, we detected from 178 to 286 compounds in the ore-bearing fluid, H2O and CO2 predominate among them. The share of hydrocarbons, their derivatives, S-, N- and halogenated compounds in total accounts for 7.4–22.6 rel. %. We assume that organic compounds were directly involved in the enrichment of quartz veins with gold mineralization. The isotope composition values of sulfur (+6.6…+9.5 ‰) and carbon from fluid inclusions in quartz (–12.5…–21.9 ‰) indicate a metamorphic-crustal source of fluids.

Valley emission and upconversion in isotopically engineered monolayer WS2 under resonant excitation

Abstract In the quest to optimize the optoelectronic and valleytronic properties of two-dimensional materials, various strategies such as strain engineering, doping, and heterostructuring have been explored. In this direction, isotope engineering also offers a potential avenue to alter electron–phonon interaction and impact quasiparticle scattering processes. In this study, we investigate the dependence of sulfur isotopes on upconversion and valley scattering phenomena by collecting the resonance photoluminescence under an applied magnetic field from 0 to 14 T at 4 K for the chemical vapor deposition-grown monolayer (1 l) of WNS2, W32S2, and W34S2. The upconversion of the mixed-state sulfur 1 l (WNS2) exhibits one M-phonon absorption, with an obtained optical gain of nearly 30 meV, while the pure sulfur isotope labelled 1 Ls (W32S2 and W34S2) require two phonons (M and Г), yielding a gain of around 80 meV. It is also found that the exciton degree of polarization (DOP) of WNS2 changes significantly by ∼ −30% as the field increases from 0 to 14 T, while for W32S2 and W34S2, the exciton DOP increases by up to ∼8%. Similarly, distinct changes in the DOP are observed for trions and localized excitons among all the samples, attributed to the different valley scattering phenomena. The 1 l WNS2 demonstrates a combination of intraband and interband scattering, whereas in the case of W32S2 intraband scattering is preferred; W34S2 predominantly exhibits interband scattering. Finally, a phenomenological model is proposed to describe the upconversion and valley scattering processes.

Dominant Role of NO2 Oxidation in SO2 Conversion to Sulfate Revealed by Synchronous Measurements of Gas and Particle Sulfur Isotopes in Haze Episodes

Dominant Role of NO₂ Oxidation in SO₂ Conversion to Sulfate Revealed by Synchronous Measurements of Gas and Particle Sulfur Isotopes in Haze Episodes

Study on the Occurrence States and Enrichment Mechanisms of the Dispersed Elements Ga, Ge, and In in the Chipu Pb-Zn Deposit, Sichuan Province, China

The dispersed elements Ga, Ge, and In are crucial strategic mineral resources often enriched in Pb-Zn deposits. The Chipu Pb-Zn deposit, located on the western edge of the Yangtze Block, lies to the north of the Sichuan-Yunnan-Guizhou (SYG) Pb-Zn metallogenic province with large amounts of Emeishan basalt. Based on trace element and in situ sulfur isotope analyses by (LA)-ICP-MS, sphalerite is the main carrier mineral for Ga (17~420 ppm), Ge (3.87~444 ppm), and In (31~720 ppm). Ga or Ge correlate significantly with Cu, while In substitutes for Zn in sphalerite alongside Fe. Key substitution reactions include Ga3+ + Cu+ ↔ 2Zn2+, Ge4+ + 2Cu+ ↔ 3Zn2+, and 2In3+ + Fe2+ ↔ 4Zn2+. Sphalerite crystallized at medium to low temperatures (114–195 °C). Sulfide δ34S values (+3.48 to +24.74‰) suggest sulfur mainly originated from Dengying Formation marine sulfates via thermochemical sulfate reduction (TSR). Metal-bearing fluid release at 30 Ma post-Emeishan mantle plume activity (261–257 Ma) coincides with the Chipu deposit’s mineralization period (230–200 Ma), suggesting the Chipu deposit is associated with Emeishan plume activity. The magmatic activity drove basinal brine circulation, extracting In from intermediate-felsic igneous rocks and metamorphic basement. Elevated temperatures promoted the coupling of Fe and In into sphalerite, causing anomalous In enrichment.

Geological and S–Pb–He–Ar isotope constraints on the origin of the Muping–Rushan gold belt, Jiaodong Peninsula, eastern China

The Muping–Rushan gold belt is one of three gold mineralization belts in Jiaodong Peninsula, eastern China, which are located between the Sulu ultrahigh-pressure metamorphic belt and North China Craton. This study investigated the source of gold and ore-forming fluids in the Muping–Rushan gold belt, based on a detailed investigation of typical gold deposits. Electron microprobe elemental mapping of pyrite and pyrrhotite showed that gold and silver occur mainly as thin veins in cracks in stage I pyrite (Py1) or around stage II pyrite (Py2). The arsenic contents are higher at the rims and in cracks of stage I pyrite (Py1) and around stage II pyrite (Py2), and are positively correlated with gold contents. In situ sulfur isotope data for sulfides in the study area are mainly between 5.8‰ and 10.1‰. The sulfides in the belt are generally characterized by δ34SPy > δ34SSp > δ34SCcp and δ34SPy4 > δ34SPy2 > δ34SPy1. The δ34S values of mineralization stages Ⅱ and Ⅲ are similar to those of the Jiaodong and Jingshan groups, and the Kunyushan complex. Lead isotopic compositions are consistent with those of the lower crust and orogenic belts. 3He/4He, 40Ar/36Ar, and 40Ar*/4He ratios of the gold deposits in the study area are 0.01–5.06 Ra, 389.8–4674.7, and 0.03–2.78, respectively, indicating the ore-forming fluids were derived mainly from the crust, with a small contribution from the mantle. The mineralization ages of gold deposits in the Muping–Rushan gold belt are mainly 114.6–104.8 Ma, with a weighted-mean age of 108.9 ± 0.7 Ma. This age is 6–8 Myr younger than the igneous rocks crystallization ages in the study area.

The origin of sulfur in Canary Island magmas and its implications for Earth’s deep sulfur cycle

The global sulfur cycle plays a critical role in the redox evolution of Earth's surface and upper mantle, yet the distribution and origin of sulfur in the mantle remains largely unconstrained. El Hierro is a volcanic island in the Canary archipelago that is fed by sulfur-rich magmas. To constrain the origin of sulfur in these melts, we combine in situ sulfur isotope analyses with regression modeling. We calculate that undegassed El Hierro melts have δ34S values of 0 ± 2‰. The average δ34S of undegassed El Hierro melts is 0.3‰ to 1‰ higher than magmas erupting at mid-ocean ridges. Mass balance calculations reveal that El Hierro's mantle source contains 310 ± 120 μg/g sulfur and that on average 60% of sulfur in the source is of recycled origin. This recycled material should contain >1,800 μg/g sulfur to satisfy isotopic constraints on its mass fraction in the mantle source. The sulfur and oxygen isotopic signature in serpentinites and sediments deviate significantly from the upper mantle, making them unsuitable candidates for the recycled material. An oxidized partial melt of recycled oceanic crust that retained one third of its sulfur budget after subduction zone processing can explain excess sulfur in the Canary Island mantle. Recycled oceanic crust is expected to contain sulfur as sulfide, which is not capable of oxidizing the mantle. The presence of ferric iron in the recycled component is necessary to produce metasomatic melts that are oxidizing enough to carry sufficient sulfur into the mantle source of ocean island basalts.

In Situ Geochemical and Sulfur Isotopic Composition of Pyrites from the Jiepailing Tin–Beryllium Polymetallic Deposit, Southern Hunan Province, China: Implications for Ore-Forming Processes

The Jiepailing deposit in southern Hunan is a typical large to super-large polymetallic tin deposit enriched in beryllium and other rare metals. To enhance the understanding of the mineralization processes of the Jiepailing deposit, detailed mineralogical, in situ geochemical, and sulfur isotopic analyses were conducted on pyrite closely associated with tin–polymetallic mineralization. Five types of pyrite have been identified in the deposit: (1) euhedral to subhedral medium- to coarse-grained pyrite (PyI) in tungsten–tin ore; anhedral fine-grained pyrite (PyII) in tin polymetallic–fluorite ore; anhedral fine-grained or aggregate pyrite (PyIII) in lead–zinc ore; euhedral to subhedral coarse-grained pyrite (PyIV) in beryllium–fluorite mineralization; and subhedral to anhedral fine-grained pyrite (PyV) in carbonate veinlets developed in the wall rock. Backscattered electron imaging indicates consistent structural features across the five types of pyrite. In situ trace element analysis reveals differences in trace element concentrations among the pyrite types. PyI is relatively enriched in Sn, Cu, and Co. In contrast, PyIII is enriched in Pb, Zn, Sn, and Ti, while PyIV and PyV are enriched in Ag and Sb. PyI has a Co/Ni ratio more than 1, while the Co/Ni ratios in the other four types of pyrite are less than 1. LA-MC-ICP-MS in situ sulfur isotope analysis shows δ34S values ranging from 2.5‰ to 5.8‰ (average 4.3‰, PyI), 2.5‰ to 5.8‰ (average 4.3‰, PyII), −7.6‰ to 9.5‰ (average 3.9‰, PyIII), −3.7‰ to 10.6‰ (average 3.6‰, PyIV), and 6.8‰ to 14.1‰ (average 9.2‰, PyV). Based on previous studies, regional geological background, deposit characteristics, and the in situ trace element and sulfur isotope compositions of pyrite, it is inferred that the various ore bodies in the Jiepailing deposit are products of Late Cretaceous magmatic–hydrothermal activity. The early ore-forming fluid originated from magmatic sources and during the migration into the wall rock and shallow formations, mixed with fluids primarily derived from atmospheric precipitation. Temperature, pressure, and composition changed of the ore-forming fluid which carried a large amount of substances, leading to tungsten–tin, tin polymetallic–fluorite, lead–zinc, and beryllium–fluorite mineralization, followed by carbonation during the late-stage mineralization.

Analyzing the Source of Sulfate in Karst Groundwater Based on a Bayesian Stable Isotope Mixing Model: A Case Study of Xujiagou Spring Area, Northern China

The source of sulfate in the groundwater of karst springs in the northern Taihang Mountains remains unclear due to the influence of multiple factors. To investigate this, 33 sampling points were selected in August 2022 across the exposed, covered, and buried areas of the spring basin, and water samples were collected. Hydrochemistry and sulfur–oxygen dual isotope methods were employed to examine the distribution characteristics of sulfate, δ18OSO4, and δ34SSO4. Based on the distinct characteristics of sulfur isotopes from different sources, the sources of sulfate in various environments were qualitatively analyzed. Additionally, the contribution rates of each source were quantitatively determined using a Bayesian stable isotope mixing model. The results showed that the sulfate content in karst groundwater ranged from 16.68 to 156.84 mg/L, with an average of 62.22 mg/L, and indicated an increasing trend from exposed to covered to buried areas. The δ34SSO4 values in karst groundwater ranged from 3.1‰ to 13.5‰, with an average of 6.49‰, while the δ18OSO4 values ranged from 2.9‰ to 10.3‰, with an average of 5.49‰. The δ34SSO4 values showed a general increasing trend across the exposed, covered, and buried areas, whereas the δ18OSO4 values remained relatively stable across these areas. The analysis revealed that the primary sulfate sources in the exposed area were atmospheric precipitation, soil sulfate, chemical fertilizer, and sewage, contributing 19.6%, 63.5%, 9.4%, and 7.5%, respectively. In the covered area, the main sources were atmospheric precipitation, sulfide oxidation, soil sulfate, and gypsum dissolution, with contributions of 16.5%, 58.7%, 15.9%, and 8.9%, respectively. In the buried area, the sulfate primary originated from atmospheric precipitation, sulfide oxidation, and gypsum dissolution, contributing 11.6%, 78.5%, and 9.9%, respectively. This study provides critical insights into the sulfate sources in different environments, enhancing the understanding of groundwater sulfate pollution in the study area. These findings provide a scientific foundation for managing groundwater pollutants and resources in the karst regions of northern China.

Oxygen and Sulfur Isotope Systematics of Dissolved Sulfate in a Nonvolcanic Geothermal System: Sulfate Source, Evolution and Impact on Geothermometers

Dual isotopes of sulfate (δ34SSO4 and δ18OSO4), along with isotopes in water and trace elements of geothermal waters, are systematically investigated to quantitatively elucidate sulfate sources and oxygen and sulfur isotopic behaviors during deep groundwater circulation and to constrain reservoir temperatures in the Jimo nonvolcanic geothermal system on the eastern coast of China. The results show that δ34SSO4 and δ18OSO4 values in geothermal waters ranged from −21.0 to 5.7‰ and from 1.1 to 8.8‰, respectively. An increase in SO4 concentrations (140–796 mg/L) with a systematic decrease in δ34SSO4 and δ18OSO4 values was observed along the flow path from the central to eastern and western parts. The sulfate in the Middle Group was predominantly from atmospheric deposition, with sulfide oxidation contributions of <27%. In contrast, 80–85% of SO4 in the Eastern Group is derived from pyrite oxidation. In the Western Group, the oxidation of multiple metal sulfides contributed 43–66% of SO4. Sulfate oxidation and mixing of shallow groundwater caused reservoir temperatures to be underestimated by 9 ± 6–14 ± 16% using silica and K-Mg geothermometers but overestimated by up to 52–62% using sulfate–water oxygen isotope geothermometers. The estimated average target reservoir temperature was 144 ± 8 °C, with geothermal waters circulating to depths of 3.6–4.6 km. This study offers new insights into the significant impact of sulfate-related processes on geothermometric estimates, a factor often overlooked when using aqueous geothermometers. It also provides valuable guidance for accurately estimating target geothermal reservoir temperatures and advancing exploration in nonvolcanic geothermal systems.

The Small-Scale Fluid Heterogeneity in the Tongguan Hydrothermal Field (27.1° S, Mid-Atlantic Ridge): Evidence from Mineralogical and Sulfur Isotope Study of the Hydrothermal Sulfide

Hydrothermal activity on the modern seafloor varies depending on the tectonic setting. In particular, the neovolcanic zones (NVZs) along mid-ocean ridges, where magmatism is intense, generally host high-temperature hydrothermal activities. These high-temperature hydrothermal activities on the NVZs can promote the development of many polymetallic sulfide deposits. Currently, many high-temperature hydrothermal activities and sulfide accumulations have been discovered on the NVZs of major mid-ocean ridges worldwide, but relatively few have been found in the Southern Mid-Atlantic Ridge (SMAR), which limits our understanding of the hydrothermal mineralization characteristics on the NVZs of SMAR. Fortunately, in 2015, a new hydrothermal field—Tongguan—developed on the NVZ of the SMAR was discovered. In this study, we conducted mineralogical and sulfur isotope studies on hydrothermal chimney and massive sulfide samples collected from the Tongguan field. We revealed the mineral composition and growth sequence in the chimney structures and sulfides and discovered two different chimney growth patterns featuring rhythmic banding and opal-filled structures. Additionally, sulfur isotopes suggest the presence of mixing between seawater within the oceanic crust and the upwelling hydrothermal fluid in this hydrothermal field. Our investigation revealed small-scale fluid heterogeneities during the submarine hydrothermal mineralization process, which is due to fluctuations in fluid temperatures and mineral deposition within individual vent frameworks. This work provides a reference for further understanding and comprehension of hydrothermal mineralization on the NVZs of SMAR.

Geochemical Fingerprinting of Siboglinid Tube Worms: Insights From Stable Isotopes (C, N, and S) and Trace Elements

AbstractAt marine methane seeps, siboglinid tube worms influence the exchange of elements between sediments and seawater and potentially represent a recorder of seep activity. The organ of siboglinids produces the chitin of the tube wall, facilitating the formation of tubes that protect the siboglinid's soft tissue. However, the mechanisms underlying element transfer and isotope fractionation between soft tissue and the chitinous tube are poorly constrained. This study analyzes the carbon, nitrogen, and sulfur isotopes as well as trace elements, including rare earth elements (REEs) and copper (Cu), compositions of tissues and tubes of the siboglinid tube worm Paraescarpia echinospica from the Haima seeps of the South China Sea. The stable isotope values of both tissue and the chitinous tube primarily reflect sulfur oxidation processes and carbon fixation by endosymbiotic sulfur‐oxidizing bacteria. The trace element composition of the soft tissue suggests the utilization of light rare earth elements (LREEs) and Cu during aerobic oxidation of methane supposedly performed by epibiotic aerobic methanotrophic bacteria. In contrast, the trace element composition (e.g., REEs, Cu) of the chitinous tube primarily records the influence of diagenetic processes and source effects. The chitinous tube is therefore apparently not a straightforward archive of the local environment and metabolic characteristics of the tube worms. Still, the discrepancies between the information stored in tissue and the chitinous tube may offer some insight for the identification of fossil seep‐dwelling tube worms if parts of the chitinous tube are preserved. Integrating element and isotope geochemistry within paleontological studies may consequently enhance our understanding of siboglinid evolution.

Implications of solid bitumen association with low- to medium-temperature hydrothermal minerals in hydrocarbon reservoirs of Southwest China: Insights from organic petrology and sulfur isotopes

Implications of solid bitumen association with low- to medium-temperature hydrothermal minerals in hydrocarbon reservoirs of Southwest China: Insights from organic petrology and sulfur isotopes

δ13C, δ15N, and δ34S isotope values from preserved elasmobranch jaws: Implications for ecological studies from existing collections.

δ13C, δ15N, and δ34S isotope values from preserved elasmobranch jaws: Implications for ecological studies from existing collections.