Organic Geochemistry最新文献

{"title":"Large variability and 2H-depletion of Middle Miocene to Pleistocene alkenone hydrogen isotopes in the Equatorial Pacific reflect subsurface, low light haptophyte growth","authors":"Katrin Hättig ,&nbsp;Panteleimon Prokopiou ,&nbsp;Stefan Schouten ,&nbsp;Marcel T.J. van der Meer","doi":"10.1016/j.orggeochem.2024.104840","DOIUrl":"10.1016/j.orggeochem.2024.104840","url":null,"abstract":"<div><p>Hydrogen isotope ratios of haptophyte derived long-chain alkenones (δ²H_C37:2) have shown to be a useful tool for reconstructing past isotopic compositions of surface seawater (δ²H_SSW). The δ²H_SSW is related to global ice volume, sea surface salinity and the local hydrological cycle. Here, we present a hydrogen isotope record of alkenones spanning the last 14.5 Ma from IODP site U1338 in the east equatorial Pacific. The alkenone-based reconstructed δ²H_SSW is substantially more negative and variable than reconstructed δ²H_SSW based on published oxygen isotopes of coccolith carbonates. This suggests that factors other than the isotopic composition of seawater affect the hydrogen isotopic composition of alkenones. The relatively negative and highly variable δ²H_C37:2 values are in line with published modern observations on alkenones from suspended particulate matter in the equatorial and north Pacific, with the highest values at relatively high light conditions at the surface and the lowest values at higher water depth and relatively low light conditions. This suggests that the relatively negative and highly variable δ²H_C37:2 values in these Middle Miocene to Pleistocene sediments are likely derived from haptophytes growing below the sea surface under variable low light conditions. In regions where the contribution of alkenones from subsurface production, due to high subsurface nutrients, at low light intensities to the sediment is relatively high the δ²H_C37:2 has to be interpreted with care as a proxy for δ²H_SSW.</p></div>","PeriodicalId":400,"journal":{"name":"Organic Geochemistry","volume":"196 ","pages":"Article 104840"},"PeriodicalIF":2.6,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0146638024001050/pdfft?md5=a69a426889b12c40d0c297c335a93ddd&pid=1-s2.0-S0146638024001050-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141781565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonality of amino acid enantiomers and microbial communities at MOLA time series in the NW Mediterranean Sea","authors":"Anabel von Jackowski ,&nbsp;Nawal Bouchachi ,&nbsp;Quentin-Boris Barral ,&nbsp;Paul Labatut ,&nbsp;Barbara Marie ,&nbsp;Olivier Crispi ,&nbsp;Karine Escoubeyrou ,&nbsp;Charles-Hubert Paulin ,&nbsp;Celine Dimier ,&nbsp;Josephine Ras ,&nbsp;Alexander Hayward ,&nbsp;Eva Ortega‐Retuerta","doi":"10.1016/j.orggeochem.2024.104839","DOIUrl":"10.1016/j.orggeochem.2024.104839","url":null,"abstract":"<div><p>Seasonality in light, temperature, and nutrient availability are well-known to regulate phytoplankton blooms and the bacterioplankton community. During the spring bloom, phytoplankton release biomolecules as part of the dissolved organic matter (DOM) pool exploited by the bacterioplankton. Here, we investigated the seasonal variability of phytoplankton biomass, enantiomers of dissolved hydrolyzable amino acids (DHAA), bacterioplankton abundances and community composition at the Microbial Observatory Laboratory Arago (MOLA) in the NW Mediterranean Sea from 2019 to 2021. Phytoplankton biomass estimated from pigment biomarkers suggests a spring bloom succession from cryptophytes, haptophytes, and prasinophytes in March to diatoms in April. The spring bloom coincided with a 50% increase in L-enantiomers of DHAA and an increase in bacterial abundance. After the spring bloom, elevated concentrations of D-enantiomers of DHAA and gamma-aminobutyric acid suggest bacterial processing of labile biomolecules contributed to the seasonal accumulation of dissolved organic carbon (DOC). Linking organic molecules with the free-living bacterioplankton community showed a seasonal succession of niches and substrate regimes. The parallel analysis of DOM and bacterioplankton community provides an important baseline for bacteria-substrate relationships over the seasonal cycle in the northwestern Mediterranean Sea.</p></div>","PeriodicalId":400,"journal":{"name":"Organic Geochemistry","volume":"196 ","pages":"Article 104839"},"PeriodicalIF":2.6,"publicationDate":"2024-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0146638024001049/pdfft?md5=2e86bb1bf2a4206301bbba0cda8f8bca&pid=1-s2.0-S0146638024001049-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141840020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemistry Articles – May 2024","authors":"","doi":"10.1016/j.orggeochem.2024.104814","DOIUrl":"10.1016/j.orggeochem.2024.104814","url":null,"abstract":"","PeriodicalId":400,"journal":{"name":"Organic Geochemistry","volume":"195 ","pages":"Article 104814"},"PeriodicalIF":2.6,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141705023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The preservation of photosynthetic and hydrological signals in the carbon and hydrogen isotope compositions of n-fatty acids in the seasonal wetland soils of the Okavango Delta (Botswana)","authors":"Julie Lattaud ,&nbsp;Mangaliso J. Gondwe ,&nbsp;Matthias Saurer ,&nbsp;Carole Helfter ,&nbsp;Cindy De Jonge","doi":"10.1016/j.orggeochem.2024.104832","DOIUrl":"https://doi.org/10.1016/j.orggeochem.2024.104832","url":null,"abstract":"<div><p>The Okavango wetland (Botswana) is the world’s largest inland delta. A strong seasonality in water input leads to the contraction and extension of wetlands in the floodplains. The extreme evapotranspiration and little precipitation lead to a difference in the hydrogen isotope signature of rain, soil and river water. Biomarkers, such as plant waxes, are stored in the soils and preserved on geological timescales. To understand which signal is preserved in the stable isotope signatures of plant waxes, soils along a 250 m-long transect spanning waterlogged to dry soils were collected over several seasons and three years. In addition, plants, and plant and soil water were collected along this transect. First, carbon isotope ratios (δ¹³C) of plant waxes (i.e, <em>n</em>-fatty acids) were used to classify their metabolism. δ¹³C of bulk organic matter and individual <em>n</em>-fatty acids analyzed in the soils show a strong dependance on the type of vegetation found along the transect (C₃ versus C₄ plants). Hydrogen isotope ratios (δ²H) of water present in soil showed that shallow-rooted C₄ grasses use superficial soil water, whereas the xylem water δ²H content in trees growing near the flooded channel indicated the use of river water. In addition, plant hydrogen fractionation between lipids and rain showed a strong influence of carbon metabolisms with larger fractionation for C₃ plants compared with C₄ grasses. <em>n</em>-fatty acid δ²H ratios in surface soils followed the hydrological variation in the Delta with its floods and dry periods. Hence δ²H of long-chain fatty acids seems to track the river-level variation rather than precipitation.</p></div>","PeriodicalId":400,"journal":{"name":"Organic Geochemistry","volume":"195 ","pages":"Article 104832"},"PeriodicalIF":2.6,"publicationDate":"2024-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0146638024000974/pdfft?md5=3e9087196b9fab43136f18bf44b2aabc&pid=1-s2.0-S0146638024000974-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141582347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of vegetation type on brGDGTs: Results from surface soils beneath sub-alpine forest and grassland under the same climatic conditions","authors":"Shikai Wei ,&nbsp;Tianyan Lin ,&nbsp;Yunxia Li ,&nbsp;Jiantao Cao ,&nbsp;Guodong Jia ,&nbsp;Mingzhi Chen ,&nbsp;Zhiguo Rao","doi":"10.1016/j.orggeochem.2024.104831","DOIUrl":"10.1016/j.orggeochem.2024.104831","url":null,"abstract":"<div><p>Branched glycerol dialkyl glycerol tetraether lipids (brGDGTs) are increasingly used for terrestrial paleotemperature reconstruction. However, there can be significant offsets between the estimated temperatures based on brGDGT distributions in globally-distributed individual surface soils and the corresponding instrumental temperatures suggesting that additional environmental and/or biological controls could influence these distributions. We investigated the influences of seasonality and vegetation type on the brGDGT distributions by collecting surface soils beneath sub<strong>-</strong>alpine forest and grassland in September (warm month) and January (cold month), within an identical climatic background, in southern China. The absence of apparent seasonal changes in the soil brGDGT distributions between the warm and cold months indicates an annual or longer turnover time of soil brGDGTs at our study site. However, there are differences in the surface soil brGDGT distributions expressed as MBT'_5ME (the methylation index that is related to mean annual temperature, i.e., MAT) between forest and grassland. Specifically, the forest surface soil MBT'_5ME values were generally lower than those of grassland surface soils, which is consistent with the relatively higher summer grassland surface soil temperatures. This reveals a seasonal (summer) bias in the brGDGT distributions, and the dominant influence of temperature and secondary/indirect influence of vegetation type on brGDGT distributions. Finally, for brGDGT distributions in the 288 globally-distributed surface soils with known vegetation types, the root mean square error (RMSE) between calculated and measured MAT is slightly decreased when the vegetation types are taken into account, which further indicates a possible secondary/indirect influence of vegetation type on surface soil brGDGT distributions.</p></div>","PeriodicalId":400,"journal":{"name":"Organic Geochemistry","volume":"196 ","pages":"Article 104831"},"PeriodicalIF":2.6,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141698408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A paleoenvironmental and ecological analysis of biomarkers from the Eocene Fossil Basin, Green River Formation, U.S.A.","authors":"Amy L. Elson ,&nbsp;Lorenz Schwark ,&nbsp;Jessica H. Whiteside ,&nbsp;Peter Hopper ,&nbsp;Stephen F. Poropat ,&nbsp;Alex I. Holman ,&nbsp;Kliti Grice","doi":"10.1016/j.orggeochem.2024.104830","DOIUrl":"10.1016/j.orggeochem.2024.104830","url":null,"abstract":"<div><p>Exceptionally well-preserved fossil specimens in the Fossil Basin of the Green River Formation (GRF) have made it the subject of extensive paleontological study, but the organic molecular framework that evolved during a key paleoclimatic and fossil-bearing interval during the early Eocene is poorly understood. Whereas the organic geochemistry of the larger co-eval GRF basins has been extensively characterized, our molecular understanding of the fossil-bearing layers in the Fossil Basin and the drivers of the exceptional fossilization therein remain unresolved. To bridge this gap, sediments from the famous 18″-layer — the fossiliferous horizon that is extensively quarried for exceptional soft-tissue fossils — were sampled for organic and isotopic geochemical characterisation. The results show that the Fossil Basin sedimentary archive is geochemically distinct from other GRF basins, as exemplified by the absence of the classical biomarker β-carotane and minimal evidence for the large green algal blooms that predominate in the other GRF lake basins. Photic zone euxinia (PZE), anoxia, and a freshwater cap enabled development of a productive and diverse ecosystem. Salinity and density stratification prevented vertical mixing of the water column and supported preservation of decaying carcasses. In contrast to other GRF basins, the small areal extent and ellipsoid shape of the Fossil Basin focussed terrestrial and freshwater inputs into the lake, resulting in ideal conditions for preservation of an exceptional fossil record.</p></div>","PeriodicalId":400,"journal":{"name":"Organic Geochemistry","volume":"195 ","pages":"Article 104830"},"PeriodicalIF":2.6,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0146638024000950/pdfft?md5=5b7861c92f5e681baa77eda2500b89e7&pid=1-s2.0-S0146638024000950-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141883039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impacts of temperature and fluid seepage on organic matter composition in sediments of an active hydrothermal basin","authors":"Niroshan Gajendra ,&nbsp;Longhui Deng ,&nbsp;Timothy I. Eglinton ,&nbsp;Carsten J. Schubert ,&nbsp;Mark A. Lever","doi":"10.1016/j.orggeochem.2024.104829","DOIUrl":"10.1016/j.orggeochem.2024.104829","url":null,"abstract":"<div><p>Marine sediments are one of the largest organic carbon (OC) sinks on Earth. Yet, major knowledge gaps remain in our understanding of sedimentary OC cycling, particularly regarding temperature-induced alteration processes of OC from different sources. Here, we investigate OC-rich sediments of Guaymas Basin (Gulf of California) across two hydrothermal areas, one with only conductive geothermal heating and the other additionally experiencing seepage of hydrocarbon-rich fluids from deeper layers. We use Pyrolysis-Gas Chromatography/Mass Spectrometry (Py-GC/MS) to investigate diagenetic OC changes and show that cold control sites in both hydrothermal areas are dominated by similar contributions of lipid-derived compounds, nitrogenous (likely protein-derived) compounds, carbohydrates, and polyaromatic hydrocarbons (PAHs). These OC compound groups are largely derived from phytoplankton detritus from overlying water. Conductively heated sediments, which reach <em>in situ</em> temperatures of ∼ 80 °C, have similar general OC compositions and contents to these cold sites, but show evidence of diagenetic modifications of individual carbohydrate groups in deeper layers. By contrast, strong decreases in carbohydrate and nitrogenous compound abundances at the seep sites indicate that these compound groups are not only modified but also selectively degraded at the higher temperatures (&gt;80 °C) of these sites. Increases in pyrolysis products of PAHs, prist-1-ene, and alkanes with depth, moreover, show that import of OC by deep hydrothermal fluids contributes significantly to sedimentary OC pools mainly in deeper layers of these sites. Our study provides the first comprehensive analysis of major OC compound groups in Guaymas Basin sediment and indicates that the supply of OC by hydrothermal fluid flow only has minor impacts on particulate organic matter compositions at the seafloor, even at active seep sites. We furthermore show that temperatures up to ∼ 80 °C already result in thermochemical modifications of organic matter (OM) that are potentially linked to the onset of kerogen formation. The sequence and time scales of chemical modifications and activations in relation to temperature are an important subject for future investigations.</p></div>","PeriodicalId":400,"journal":{"name":"Organic Geochemistry","volume":"196 ","pages":"Article 104829"},"PeriodicalIF":2.6,"publicationDate":"2024-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0146638024000949/pdfft?md5=a049911ddd7756c3351e26479b9c01f0&pid=1-s2.0-S0146638024000949-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142040989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On precision and accuracy: A review of the state of compound-specific isotope analysis of amino acids","authors":"Audreyana L.N. Nash ,&nbsp;Seth D. Newsome ,&nbsp;Kelton W. McMahon","doi":"10.1016/j.orggeochem.2024.104823","DOIUrl":"10.1016/j.orggeochem.2024.104823","url":null,"abstract":"<div><p>Compound specific stable isotope analysis of amino acids (CSIA-AA) is a practice that allows for in-depth studies of many different physiological, ecological, and environmental phenomena. The vast information obtainable through CSIA-AA has driven the exponential growth of this field since its mainstream introduction in the early 1990s. This growth, however, has been accompanied by the development of several distinct analytical approaches. Throughout this review, we outline the full CSIA-AA process and identify areas of its workflow with the highest potential to introduce measurement error. Through a meta-analysis of CSIA-AA publications, we found that rather than experimental application, the primary determinant of methodology lies in the geographic location of the analyst, likely reflective of the academic lineages of CSIA-AA practitioners as opposed to application specific method development. The relative nascency of amino acid isotope analysis gives it incredible expansion potential, but such expansion would greatly benefit from comprehensive experimentation optimizing every portion of the analytical process. While such optimization will require expertise across many areas (i.e., chemistry, mass spectrometry, and data science), uniform guidelines can ensure the highest achievable accuracy and precision for intra- and interlaboratory analyses, alike. The goal of this review is to improve data comparability and adopt standardized methodologies to uniformly generate highly accurate, precise, and reproducible data. In doing so, we make recommendations for areas that would benefit from further investigation (e.g., procedure optimization, error mitigation, and data handling methods). The creation and implementation of guidelines for optimal approaches to CSIA-AA – as has been done for applications like forensic science – can help realize the full potential of this rapidly growing field.</p></div>","PeriodicalId":400,"journal":{"name":"Organic Geochemistry","volume":"195 ","pages":"Article 104823"},"PeriodicalIF":2.6,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0146638024000883/pdfft?md5=cdca87150839a3714e52c9d2b08aa50c&pid=1-s2.0-S0146638024000883-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141781942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Organic matter composition in sediments recording sea surface phytoplankton community structure in Prydz Bay of Antarctica","authors":"Xiaoze Guo ,&nbsp;Jun Zhao ,&nbsp;Jianming Pan ,&nbsp;Yongge Sun","doi":"10.1016/j.orggeochem.2024.104828","DOIUrl":"https://doi.org/10.1016/j.orggeochem.2024.104828","url":null,"abstract":"<div><p>The coastal zones in Antarctica play an important role in the polar carbon cycle through the efficiency of the biological pump. In this study, Prydz Bay in East Antarctica was selected to investigate factors controlling organic matter composition in sediments using source-dependent biomarkers. The results show that fatty acids are the most abundant biomarkers in sediments, followed by sterols, fatty alcohols, and alkanes. Although microalgae are well known to be the main source of sedimentary organic matter in Prydz Bay, the distribution of low molecular weight branched alkanes and alkenes with an even–odd predominance suggest the importance of bacteria during organic matter transformation, and its contribution to sedimentary organic matter. High concentrations of highly branched isoprenoid alkenes (HBIs) with a distinctive enriched ¹³C signature indicate substantial inputs of ice algae to sediments. Principal component analysis of source-dependent biomarkers reveals that the spatial heterogeneity of organic composition in sediments of Prydz Bay is mainly controlled by the distribution of sea surface phytoplankton community in different geographical zones. Redundancy analysis demonstrates that seasonal sea-ice cover is the main driver for blooms of distinctive algae in each geographical zone as a result of spatial succession of the phytoplankton community. The result clearly exhibits that, at least in Prydz Bay, spatial succession of the sea surface phytoplankton community in austral summer can be recorded in sediments, suggesting that a high-resolution sediment record of source-dependent biomarkers can be used to reconstruct the evolution of sea surface phytoplankton community structure during geological history in Antarctic coastal zones.</p></div>","PeriodicalId":400,"journal":{"name":"Organic Geochemistry","volume":"195 ","pages":"Article 104828"},"PeriodicalIF":2.6,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141607457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gas-phase reaction of CH4 and H2S – Evidence from pyrolysis experiments and case study from the Sichuan Basin","authors":"Ilya Kutuzov ,&nbsp;Qilin Xiao ,&nbsp;Alon Amrani","doi":"10.1016/j.orggeochem.2024.104826","DOIUrl":"https://doi.org/10.1016/j.orggeochem.2024.104826","url":null,"abstract":"<div><p>The application of routine geochemical analyses for identification of dry natural gas sources and post generation processes poses a challenge as its hydrocarbon composition is typically dominated by CH₄ (∼≥99 %) while the presence of non-hydrocarbons may be limited. In particular, the possibility of dry gas interaction with H₂S at reservoir conditions (low temperatures, high pressures, millions of years residence time) is not established as previous studies of this reaction focused on conditions typical for industrial reactors (high temperature, ambient pressure, residence time of seconds). To address these issues, we studied the molecular and isotopic (δ³⁴S) composition of volatile organic sulfur compounds (VOSC) formed during pyrolysis experiments between CH₄ and H₂S at 360 °C (4–96 h), reaching %Ro equivalent of 0.80–1.25 which represents thermally mature oil and gas reservoirs. The results demonstrated that methanethiol (MeSH) is the main product of the reaction, while its δ³⁴S value suggest equilibrium isotopic effect with its parent H₂S. Subsequent analysis of the molecular and isotopic (δ¹³C, δ²H, δ³⁴S) composition of thermogenic, H₂S containing, dry natural gases from the Jiannan gas field in China revealed the presence of short thiols and sulfides dominated by MeSH. The δ³⁴S of the VOSC identified suggests they all formed by gas-phase reaction of alkanes (mainly CH₄) with the associated H₂S.</p><p>This study demonstrates the applicability of VOSC as a proxy for identification of interaction between H₂S and dry gas and identification of H₂S sources within a gas reservoir or a basin.</p></div>","PeriodicalId":400,"journal":{"name":"Organic Geochemistry","volume":"194 ","pages":"Article 104826"},"PeriodicalIF":2.6,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141433901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}