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Molecular and carbon isotopic evidence for the possible origin of 13α(n-alkyl)-tricyclic terpanes in Mesoproterozoic bitumens from the Yanliao Rift, North China Org. Geochem. (IF 3.0) Pub Date : 2024-03-13 Tao Zhang, Ping'an Peng, Yongfei Li, Shouliang Sun, Huijuan Guo, Haiming Pang
The Mesoproterozoic Jixian System in the Yanliao Rift of the North China Craton contains organic-rich shales within the Hongshuizhuang, Tieling, and Xiamaling formations. The biomarker composition of these formations is characterized by the dominance of 13α(-alkyl)-tricyclic terpanes. The distinctive structure and main occurrence of 13α(-alkyl)-tricyclic terpanes in the Mesoproterozoic Jixian System
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Taraxerol abundance as a proxy for in situ Mangrove sediment Org. Geochem. (IF 3.0) Pub Date : 2024-03-11 Juliet P. Sefton, Andrew C. Kemp, Christopher H. Vane, Alexander W. Kim, Christopher E. Bernhardt, Jonathan Johnson, Simon E. Engelhart
Mangrove sediments are valuable archives of relative sea-level change if they can be distinguished in the stratigraphic record from other organic-rich depositional environments (e.g., freshwater swamps). Proxies for establishing environment of deposition can be poorly preserved (e.g., foraminifera) in mangrove sediment. Consequently, differentiating mangrove and freshwater sediment in the stratigraphic
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The presence of free benzenepolycarboxylic acids (BPCAs) may result in the overestimation of dissolved black carbon in aqueous samples Org. Geochem. (IF 3.0) Pub Date : 2024-03-07 Riley Barton, Isabella Winston, Sasha Wagner
Dissolved black carbon (DBC) is the condensed aromatic fraction of dissolved organic matter produced during the thermal alteration of organic material (e.g., fire). DBC concentrations are often determined using the benzenepolycarboxylic acid (BPCA) method where condensed aromatic structures are oxidized into BPCA molecular markers for quantification. However, BPCA molecules have been recently identified
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Root-derived carbon stocks in formerly deep-ploughed soils – A biomarker-based approach Org. Geochem. (IF 3.0) Pub Date : 2024-02-25 D.J. Burger, S.L. Bauke, F. Schneider, A. Kappenberg, M.I. Gocke
Roots can add significant amounts of carbon (C) to the subsoil, which improves soil physical properties and can mitigate climate change. About 5% of croplands in Germany have been deep-ploughed (30–120 cm) at least once. This can provide better root access to the subsoil and may increase yields, but little is known on the fate of root-derived C in the subsoil (at depth greater than 30 cm) after deep-ploughing
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Geochemical evidence for biodegradation in high-rank coals from Qinshui Basin, North China Org. Geochem. (IF 3.0) Pub Date : 2024-02-23 Biying Chen, Xinchu Wang, Lujia Fang, Rob M. Ellam, Sheng Xu
Understanding the generation of secondary microbial methane (SMM) is important for the evaluation of natural gas resources and instructive for the stimulation of methane production. Coal seams are popular targets for extracting in situ preserved methane and studying microbe-stimulated methane yield. However, few studies have been done on overmature coals. Here we collected gas samples from coals varying
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Evolution of kerogen structure during the carbonization stage Org. Geochem. (IF 3.0) Pub Date : 2024-02-22 Yu Liu, Siyi Xie, Guangjun Feng, Chi Su, Qiannan Xu, Tengwei Gao
Currently, certain unconventional gas is mainly extracted from high-maturity shale reservoirs, but limited attention has been given to the evolution of kerogen structure subsequent to the overmature, gas generative stage, corresponding to metagenesis and is termed the carbonization stage. In this study, we performed heating treatment on overmature kerogen samples to obtain samples in the carbonization
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Pyrolysis experiments of model compounds to explore carbon isotope fractionation in propane from natural gas Org. Geochem. (IF 3.0) Pub Date : 2024-02-14 Wen Liu, Yun Li, Wenmin Jiang, Ping'an Peng, Yongqiang Xiong
Investigating the mechanisms that determine the bulk and position-specific carbon isotopic distributions of propane in natural gas will help elucidate its formation and evolution. We used octadecane and squalane as model compounds that give simple precursors for gas production in gold-tube isothermal pyrolysis experiments to study the variations in intermolecular and intramolecular distributions of
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Quantification of allochthonous and autochthonous organic carbon in large and shallow Lake Wuliangsu based on distribution patterns and δ13C signatures of n-alkanes Org. Geochem. (IF 3.0) Pub Date : 2024-02-06 Qingfeng Zhao, Aifeng Zhou, Yuxin He
Identification and quantification of allochthonous and autochthonous organic carbon (OC) in large and shallow lakes are crucial for knowledge of OC burial and recycling behaviors, as well as sustainable management practices. However, quantitative methods to estimate the contributions from various OC sources are still limited. In this study, we analyzed distribution patterns and δC signatures of mid-
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Variations in microbial residue carbon and its contribution to soil organic carbon after vegetation restoration on farmland: The case of Guinan County Org. Geochem. (IF 3.0) Pub Date : 2024-02-01 Na Li, Yalin Wang, Lin Wei, Xungang Wang, Qian Zhang, Tongqing Guo, Xianli Xu, Na Zhao, Shixiao Xu
Microbial residue carbon (C) serves as a significant source of soil organic carbon (SOC). However, the contribution of microbial residue C to SOC accumulation after the restoration of farmland vegetation remains unclear, making it challenging to comprehend the role of microorganisms in the accumulation and transformation of SOC after vegetation restoration on farmland. Based on field investigations
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Geochemistry Articles – December 2023 Org. Geochem. (IF 3.0) Pub Date : 2024-01-23
Abstract not available
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GEOCHEMISTRY ARTICLES – November 2023 Org. Geochem. (IF 3.0) Pub Date : 2024-01-23
Abstract not available
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Intramolecular carbon isotopic rollover in propane from natural gas reservoirs of the Santanghu Basin: Insights into chemical structure of kerogen Org. Geochem. (IF 3.0) Pub Date : 2024-01-23 Peng Liu, Xiaofeng Wang, Changjie Liu, Ying Lin, Ruiliang Guo, Wenhui Liu
An intramolecular isotopic study was conducted on natural gases from the Santanghu Basin in China. Propane samples spanned a wide range of ΔC-T (δ13Ccentral-δ13Cterminal) values from –8.4 to 8.5 ‰, δ13Ccentral and δ13Cterminal values varied from –37.3 to –25.8 ‰ and –35.7 to –28.9 ‰, respectively. During thermal maturation, the position-specific carbon isotopic composition of propane shifted from
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Molecular transformations of heteroatomic organic compounds in crude oils caused by biodegradation and subsequent thermal maturation: Insights from ESI FT-ICR MS Org. Geochem. (IF 3.0) Pub Date : 2024-01-20 Bin Jiang, Weimin Liu, Yuhong Liao, Ping'an Peng
The Tarim and Junggar basins are major petroliferous sedimentary deposits in China. Some oil reservoirs in these basins experienced superimposed secondary alterations including early biodegradation followed by thermal maturation/alteration (SSA-B&M). Heteroatomic polar organic compounds in crude oil are significantly influenced by SSA-B&M, which play a vital role in understanding the evolutionary history
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The bacterial influencing mechanisms of salinity fluctuations in a brackish-water lake on the dissolved organic matter characteristics of pore water Org. Geochem. (IF 3.0) Pub Date : 2024-01-20 Lei Xie, Dezhi Zuo, Yushen Ma, Xiang Zhu, Bin Xu, Fei He, Qingqing Pang, Longmian Wang, Fuquan Peng, Lixiao Ni, Wenjuan Jiang, Haibo Dong
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Seasonal temperature dependency of aquatic branched glycerol dialkyl glycerol tetraethers: A mesocosm approach Org. Geochem. (IF 3.0) Pub Date : 2024-01-17 Fatemeh Ajallooeian, Longhui Deng, Mark Alexander Lever, Cindy De Jonge
BrGDGTs, membrane-spanning lipids produced by bacteria, are at the basis of the MBT’, a biomarker ratio that has been used as a paleotemperature proxy. However, the response of the MBT’ to temperature changes, particularly in freshwater systems, remains incompletely understood. In this study, oxic mesocosms are used to assess the temperature sensitivity of brGDGTs and their producers, sampled from
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First report of Early Permian Tasmanite oil shales in northern Pangea with global implications Org. Geochem. (IF 3.0) Pub Date : 2024-01-13 Ruijie Zhang, Jian Cao, Wenxuan Hu, Lizeng Bian, Yuce Wang, Bin Zhang, Liuwen Xia, Suping Yao, Yong Tang
During the Late Paleozoic Ice Age (LPIA; particularly early Permian), organic material of the alga Tasmanites was extensively deposited in sediments of southern Gondwana, which formed the Tasmanite oil shales that have only been identified in Tasmania, Australia. It remains unclear whether other analogous geological records exist worldwide that formed at the same time, and the origin is enigmatic.
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Archaeal lipid biomarkers in near-surface sediments at a giant colony of the bivalve Calyptogena: Molecular records of a massive methane release event associated with methane hydrate dissociation Org. Geochem. (IF 3.0) Pub Date : 2024-01-12 Susumu Sakata, Urumu Tsunogai, Masahiro Oba, Tomomi Ujiie, Manabu Tanahashi
To investigate the possibility that dissociation of subsurface methane hydrate (MH) in the eastern Nankai Trough, offshore of Japan, led to the formation of a giant colony of the bivalve Calyptogena (currently mostly dead), the carbon isotope ratios (δ13C) of archaeal lipids and methane were measured in near-surface core sediments at Daini-Tenryu Knoll. The irregular variation of porewater methane
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High abundances of degraded triterpenoids in Miocene turbiditic sediments of south-central Hokkaido, Japan Org. Geochem. (IF 3.0) Pub Date : 2024-01-06 Hiroyasu Asahi, Ken Sawada
Aliphatic and aromatic degraded triterpenoids (TTs), including des-A and des-E TTs, were investigated in turbiditic and hemipelagic mudstones from the Miocene Kawabata Formation (Ishikari basin) and Abetsu and Nibutani formations (Hodaka basin) of south-central Hokkaido, Japan. des-A TTs with carbon skeletons of oleanane, ursane, and lupane are derived from angiosperms, while des-E TTs with hopane
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Paleoceanographic importance of tri- and di-unsaturated alkenones through the early phase of Cretaceous Oceanic Anoxic Event 2 from southern high latitudes of the proto-Indian Ocean Org. Geochem. (IF 3.0) Pub Date : 2023-12-26 Takashi Hasegawa, Akiko S. Goto
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The occurrence and geochemical origin of 9-alkyl HDBTs substituted by long isoprenoid alkyl chains in crude oil Org. Geochem. (IF 3.0) Pub Date : 2023-12-22 Jianxun Wu, Abdelrahman A. Hamid, Weilai Zhang, Shuofan Li, Yahe Zhang, Yuhong Liao, Quan Shi
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Robert Alexander Obituary died 28th July 2023 (82 years) Org. Geochem. (IF 3.0) Pub Date : 2023-12-21
Abstract not available
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Possible application of bicyclic sesquiterpanes to evaluate the thermal maturity of oils. A study of Kamchatka and Chukotka oils from Cenozoic deposits, Russia Org. Geochem. (IF 3.0) Pub Date : 2023-12-15 Irina Konopleva
The distribution of bicyclic sesquiterpanes in crude oils was studied to assess the applicability of the sesquiterpane ratios as maturity parameters. GC–MS analysis was conducted on ten oil samples that were generated in Miocene-Paleogene deposits located within the Kamchatka Peninsula and southeast Chukotka, the Russian Far East. During catagenesis, there is a shift in the distribution of sesquiterpanes
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Geochemistry Articles – September 2023 Org. Geochem. (IF 3.0) Pub Date : 2023-12-12
Abstract not available
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Does leaf wax isotopic characterisation of gymnosperms and angiosperms capture environmental gradients in Himalayas? Org. Geochem. (IF 3.0) Pub Date : 2023-12-10 Deepak Kumar Jha, Pranav Hirave, Sambit Ghosh, Bibhasvata Dasgupta, Prasanta Sanyal
The responses of angiosperms and gymnosperms to environmental variables (e.g., rainfall [MAP], temperature [MAT] and pCO2) remain ambiguous and require systematic investigation. This study monitored the plants' responses to changing environments and measured variations in molecular n-alkane indices, δ13Cbulk, δ13Cn-alkanes, and δ2Hn-alkanes values in woody gymnosperms (n = 36) and angiosperms (n = 17)
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GEOCHEMISTRY ARTICLES – October 2023 Org. Geochem. (IF 3.0) Pub Date : 2023-12-06
Abstract not available
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Source and significance of Cretaceous oil seepage in the northern Ordos Basin, China Org. Geochem. (IF 3.0) Pub Date : 2023-12-08 Mai Zhang, Daofu Song, Tieguan Wang, Faqi He, Wei Zhang, Chuan An, Anliang Liu, Jiadong Yan
It has long been believed that the region on the north of the Dongsheng gas field has only limited exploration potential due to the lack of effective source rocks. However, several areas of Cretaceous oil seepage have been discovered in the area and their sources are unclear. In this study, the organic geochemical characteristics of these oil seepages and potential source rocks (coals and carbonaceous
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Distribution, occurrence and identification of dibenzofuran, benzo[b]naphthofurans and their alkyl derivatives in Gippsland Basin source rocks Org. Geochem. (IF 3.0) Pub Date : 2023-12-08 Lian Jiang, Hans P. Nytoft, Inna Kampoli, Simon C. George
Dibenzofuran, benzo[b]naphthofurans and a series of their alkylated isomers were identified in coal, coaly shale, and shale extracts from the Gippsland Basin (Victoria, Australia). The dibenzofuran series include C0-C4 dibenzofurans, and the benzo[b]naphthofuran series are composed of benzo[b]naphthofuran, methylbenzo[b]naphthofurans, and possible dimethylbenzo[b]naphthofurans. Seventeen C2 dibenzofurans
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The molecular composition of leaf lipids changes with seasonal gradients in temperature and light among deciduous and evergreen trees in a sub-humid ecosystem Org. Geochem. (IF 3.0) Pub Date : 2023-12-06 Zhao Wang, Joseph D. White, William C. Hockaday
Forest canopy structure is a fundamental ecosystem attribute affecting regional and global climate through primary production by CO2 drawdown and evapotranspirative feedback. Environmental changes in temperature and light affect leaf physiology and thus canopy functioning. Leaf physiological changes may be reflected in expressed chemical compounds (e.g., leaf lipid biomarkers), that offer opportunities
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The biological source and paleoenvironment implication of rare short-chain lanostanes in alkaline lacustrine sediments Org. Geochem. (IF 3.0) Pub Date : 2023-11-21 Dongyong Wang, Meijun Li, Jianfa Chen, Hong Xiao, Xianli Zou, Lu Yang, Haochen Chen, Huiqiang Qin
Highly mature organic-rich source rocks in the Early Permian Fengcheng Formation, Mahu Sag, Junggar Basin, northwestern China, were deposited in an alkaline lacustrine environment. Analysis of extracts of eight core samples by gas chromatography–mass spectrometry detected a series of short-chain lanostanes (C23–C25) lanostanes. The relative abundance of short-chain lanostanes has a strong positive
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The impact of soil chemistry, moisture and temperature on branched and isoprenoid GDGTs in soils: A study using six globally distributed elevation transects Org. Geochem. (IF 3.0) Pub Date : 2023-11-22 Cindy De Jonge, Jingjing Guo, Petter Hällberg, Marco Griepentrog, Hamdi Rifai, Andreas Richter, Edson Ramirez, Xinbao Zhang, Rienk H. Smittenberg, Francien Peterse, Pascal Boeckx, Gerd Dercon
Glycerol dialkyl glycerol tetraethers (GDGTs) are microbial membrane-spanning lipids that are produced in a variety of environments. To better understand the potentially confounding effect of soil chemistry on the temperature relationship of branched GDGTs (brGDGTs), isoprenoid GDGTs (isoGDGTs) and GDGT-based proxies MBT’5ME and TEX86, soils from 6 elevation transects (mean annual air temperature 0
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GEOCHEMISTRY ARTICLES – August 2023 Org. Geochem. (IF 3.0) Pub Date : 2023-11-14
Abstract not available
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Reproducibility of Rock-Eval® thermal analysis for soil organic matter characterization Org. Geochem. (IF 3.0) Pub Date : 2023-11-08 Lorenza Pacini, Thierry Adatte, Pierre Barré, Mohammed Boussafir, Nicolas Bouton, Lauric Cécillon, Violaine Lamoureux-Var, David Sebag, Eric Verrecchia, Adrien Wattripont, François Baudin
Rock-Eval® (RE) is a thermal analysis technique increasingly used to characterise soil organic matter. To interpret the results, particularly when investigating differences between samples, it is necessary to know the expected ranges of analytical error associated with the RE measurements. Moreover, the RE analyzer is now at its seventh version (RE7) while most literature results were produced using
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Distributions of vanadyl and nickel porphyrins in the Woodford Shale and selective chelation of metal species by different tetrapyrrole configurations Org. Geochem. (IF 3.0) Pub Date : 2023-11-08 Derek R. Parks, Xiao-Lei Liu
Abundant vanadyl (VO) and nickel (Ni) porphyrins were detected in the Late Devonian–Early Mississippian Woodford formation shales using a recently developed reverse-phase liquid chromatography quadrupole time-of-flight mass spectrometry with electrospray ionization (RPLC-ESI-qTOF-MS) method. This Woodford shale sequence is characterized by the presence of sustained photic zone euxinia (PZE), as indicated
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Branched GDGT source shift identification allows improved reconstruction of an 8,000-year warming trend on Sumatra Org. Geochem. (IF 3.0) Pub Date : 2023-11-03 Petter L. Hällberg, Frederik Schenk, Guillermo Jarne-Bueno, Yolanda Schankat, Qiong Zhang, Hamdi Rifai, Marcus Phua, Rienk H. Smittenberg
Branched Glycerol Dialkyl Glycerol Tetraethers (brGDGTs) in sedimentary archives are increasingly used for paleotemperature reconstructions due to their strong correlation with mean annual air temperature. However, environmental factors can influence the brGDGT producing bacterial community, potentially affecting the brGDGT-temperature relationship and introducing fundamental errors in reconstructions
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Characteristics of bound biomarkers released from pyrobitumens generated from the cracking of different types of crude oils Org. Geochem. (IF 3.0) Pub Date : 2023-10-28 Xinyan Fang, Liangliang Wu, Ansong Geng, Yun Li, Wenmin Jiang, Bin Cheng, Shufen Liu, Pufan Wang
Pyrobitumen has attracted significant attention from petroleum geologists and geochemists due to its close relationship with crude oil and natural gas. Generally, the analysis of free biomarkers in pyrobitumen is of limited use, because these biomarkers can be easily modified by biodegradation and thermal alteration. The utilization of bound biomarkers in pyrobitumen appears to be a viable solution
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Genetic significance of carbon isotope curve types of methane, ethane, and propane in natural gas Org. Geochem. (IF 3.0) Pub Date : 2023-10-29 Lixin Pei, Wenhui Liu, Qiang Guo, Xiaofeng Wang, Houyong Luo, Qingtao Wang
The carbon isotope curve (δ13Cn versus 1/n) is often used to evaluate the origin and secondary alteration of hydrocarbon gases, but the factors that influence the carbon isotope curve are not fully understood, limiting its practical application. We define a carbon isotope curve index (CICI) to quantitatively characterize the curve type. Four general curve types are defined: a Normal (δ13C1 < δ13C2 < δ13C3)
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Biodegradation effects on the distribution of aromatic carotenoids in crude oils Org. Geochem. (IF 3.0) Pub Date : 2023-10-27 Tian Xia, Yongge Sun
In this study, we use a previously confirmed group of progressively biodegraded oils to investigate the biodegradation effects on the distribution of aromatic carotenoids. The results clearly show that compared to the saturated C40 β-carotane, all aromatic carotenoids detected in crude oils were affected by biodegradation. Significant changes mainly occur after moderate biodegradation and trace or
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Natural and laboratory-induced maturation of kerogen from the Vaca Muerta Formation: A comparison study Org. Geochem. (IF 3.0) Pub Date : 2023-10-06 Jorge Andrés Donadelli, Juan Pineda, Marcos Comerio, Clara Smal, Georgina Erra, Rodolfo Hector Acosta, Gerardo Martinez Delfa
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Thermal maturity calculation in Type II-S source rocks using the alkyl dibenzothiophenes Org. Geochem. (IF 3.0) Pub Date : 2023-10-06 Poorna Srinivasan, David Jacobi, Estefania Michelle Endara Arguello, Ibrahim Atwah, Harald Karg, Abdulhameed Azzouni
Distributions of the alkyl dibenzothiophenes (DBT) are proven as effective proxies for the thermal maturity of bitumen extracts and oils expelled from marine source rocks containing Type II-S kerogen. Here we report on an expanded sample suite and DBT ratios to further refine these relationships. This study investigates the methyldibenzothiophenes (MDBT), dimethyldibenzothiophenes (DMDBT), and tri
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Environmental controls on the distribution of GDGT molecules in Lake Höglwörth, Southern Germany Org. Geochem. (IF 3.0) Pub Date : 2023-10-04 Sudip Acharya, Roland Zech, Paul Strobel, Marcel Bliedtner, Maximilian Prochnow, Cindy De Jonge
Tetraether lipids, such as glycerol dialkyl glycerol tetraethers (GDGTs), are an increasingly used proxy for reconstructing paleoclimatic and paleoenvironmental dynamics. On a global scale, environmental drivers controlling the distribution of GDGTs in lake systems have been described extensively. However, the drivers that control down-core sedimentary GDGT composition within single lake systems are
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Preservation, diagenetic transformation and paleoecological significance of fungal saccharides from lignites and fossil wood Org. Geochem. (IF 3.0) Pub Date : 2023-10-01 Leszek Marynowski, Justyna Smolarek-Lach, Prakash K. Singh, Bernd R.T. Simoneit
Fungi are a common component of terrestrial ecosystems, although their preservation as molecular fossils is relatively rare. Saccharides, such as arabitol, mannitol and trehalose, are important in biochemical processes, and are the dominant compounds in fungi, lichens and yeasts. Here we present gas chromatography–mass spectrometry (GC–MS) analysis of fungal saccharides in brown coal extracts and compare
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Determination and petroleum geochemical significance of short-chain alkylbenzenes in lacustrine source rocks Org. Geochem. (IF 3.0) Pub Date : 2023-09-28 Zhao-Wen Zhan, Guo-Xiang Wang, Yankuan Tian, Xin Zhan, Tian Liang, Yao-Ping Wang, Yan-Rong Zou, Ping'an Peng
The determination of short-chain alkylbenzenes (C0-4) in source rocks has always been a challenge due to potential losses during pretreatment processes such as solvent extraction of the soluble organic matter. This work proposes a method for analyzing short-chain alkylbenzenes in solid powder samples from source rocks by combining headspace (HS)-solid phase microextraction (SPME)-Arrow and gas chromatography-mass
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Phase behavior and GOR evolution using a natural maturity series of lacustrine oil-prone shale: Implications from compositional modelling Org. Geochem. (IF 3.0) Pub Date : 2023-09-26 Bo Liu, Nicolaj Mahlstedt, Brian Horsfield, Shansi Tian, Qiuli Huo, Zhigang Wen, Zhejun Pan
For the exploration of shale oil, there is still an urgent need to relate hydrocarbon generation reactions and changing phase behavior to exact levels of thermal maturity. Six organic-rich shale samples from the Cretaceous Qingshankou Formation, Songliao Basin spanning the maturity range with vitrinite reflectance (Ro) 0.58%–1.16% were studied for petroleum generation characteristics using the PhaseKinetics
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n-Alkane and terpenoid fingerprints of modern biomass producers unveil floral changes recorded in postglacial alpine lake sediments, Tatra Mountains, Slovakia Org. Geochem. (IF 3.0) Pub Date : 2023-09-17 Lucia Žatková, Rastislav Milovský, Achim Bechtel, Dušan Starek, Radovan Pipík, Juraj Šurka
Sediments of two alpine lakes in Tatra Mts., Slovakia, record the environmental history of their catchments from deglaciation in Late Glacial warming up to the Subboreal period. We present a biomarker-based reconstruction of changes in the surrounding biota of two contrasting lakes – a relic lake in open fen Trojrohé pleso (TROJ) and a tarn lake Batizovské pleso (BAT). Taking advantage of young unaltered
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Characteristics of n-alkyl lipids in cultivated Sphagnum and their preservation potential in the topsoil of Sphagnum farmlands in southwest China Org. Geochem. (IF 3.0) Pub Date : 2023-09-17 Qianbei Gao, Guang Yang, Jiantao Xue, Xianyu Huang
Sphagnum, a crucial peat-forming plant, is essential for sustaining the ecosystem and counteracting climate change. In recent years, attempts have been made to cultivate Sphagnum commercially to reduce the environmental impacts of harvesting the natural Sphagnum. However, research on the distribution of lipids in cultivated Sphagnum and their potential for preservation potential in the underlying soil
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Hydrogen isotope biogeochemistry of plant waxes in paired lake catchments Org. Geochem. (IF 3.0) Pub Date : 2023-09-09 Mariliis Eensalu, Daniel B. Nelson, Anna Buczynska, Oliver Rach, Eric S. Klein, Justin P. Dodd, Anneli Poska, Nathan D. Stansell
Studies of plants in modern catchment systems can serve to improve the level of understanding of sedimentary plant wax hydrogen isotope (δ2H) data by directly investigating the link between local climate conditions, plant source water, leaf water, and plant lipids for individual plant species. Here we present such an application to compare two lake catchments with different basin morphologies in Estonia
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GEOCHEMISTRY ARTICLES – July 2023 Org. Geochem. (IF 3.0) Pub Date : 2023-09-07
Abstract not available
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Constraining multi-stage and protracted oil generation of alkaline lacustrine source rocks by heteroatomic compounds Org. Geochem. (IF 3.0) Pub Date : 2023-09-06 Jingkun Zhang, Jian Cao, Baoli Xiang, Ni Zhou, Wanyun Ma, Dan He
It is unclear whether source rocks deposited in ancient alkaline lakes undergo multiple stages of hydrocarbon generation, particularly of oils. In this study, the lower Permian Fengcheng Formation in the Junggar Basin, China, was investigated using the geochemistry of heteroatomic species, with a focus on N-containing compounds, by negative-ion electrospray high-resolution Fourier transform ion cyclotron
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Early decomposition and transformation of organic matter in natural and disturbed boreal forests Org. Geochem. (IF 3.0) Pub Date : 2023-09-07 Anjelica Kondratova, Irina Kotel'nikova, Elizaveta Susloparova, Tatiana Yurkova, Semyon Bryanin
The state of boreal larch forests near the southern permafrost margin in eastern Eurasia varies considerably, even on a local scale, as a result of anthropogenic disturbances (e.g., clear-cuts and fires) and uneven permafrost distribution. This study aimed to investigate whether various ecosystem conditions affect litter decomposition and organic matter (OM) transformation. Here, we present the results
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Impact of biodegradation on methyltrimethyltridecylchromans (MTTCs) in crude oils from the Bohai Bay Basin, China Org. Geochem. (IF 3.0) Pub Date : 2023-09-05 Xiaoyong Yang, Youjun Tang, Yi Yang, Haifeng Yang, Feilong Wang, Xiaoxia Lü
Methyltrimethyltridecylchromans (MTTCs), a class of aromatic hydrocarbon molecular marker compounds, provide an assessment of paleosalinity and maturity in sediments and crude oils. However, little is known about the effect of biodegradation on MTTCs. In this study, the saturated and aromatic fractions of a suite of oils from the Neogene Guantao (N1g) and Minghuazhen (N1m) Formation in the Miaoxi Depression
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Unusual 13C depletion in the central carbon of propane in the gases of Longmaxi shale in the Sichuan Basin Org. Geochem. (IF 3.0) Pub Date : 2023-08-24 Yanhua Shuai, Yongqiang Xiong, Jian Li, Wei Wu, Guoyi Hu
Abiotically synthesized hydrocarbons are significant in the fields of astrobiology, biosphere, energy, environment, and geology. Abiotic hydrocarbons have never been unambiguously proven to occur in common sediments partly because identifying these components in crustal settings is challenging as they share similar characteristics with hydrocarbons of biotic origin. In this study, we measured intramolecular
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Regional vs. global temperature calibrations for lacustrine BrGDGTs in the North American (sub)tropics: Implications for their application in paleotemperature reconstructions Org. Geochem. (IF 3.0) Pub Date : 2023-08-24 Yanyan Lei, Damara J. Strong, Margarita Caballero, Alex Correa-Metrio, Liseth Pérez, Antje Schwalb, Laura Macario-González, Sergio Cohuo, Socorro Lozano-García, Beatriz Ortega-Guerrero, Josef P. Werne
Branched glycerol dialkyl glycerol tetraethers (brGDGTs) have shown great promise in lacustrine temperature reconstructions across different continents. While brGDGTs have been reported from many different regions and global brGDGT-temperature calibrations have been developed with various methods, southern North America remains an understudied area with little available data. In this study, we analyzed
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Advancing chemical lability assessments of organic matter using a synthesis of FT-ICR MS data across diverse environments and experiments Org. Geochem. (IF 3.0) Pub Date : 2023-08-23 Juliana D'Andrilli, Carlos M. Romero, Phoebe Zito, David C. Podgorski, Robert A. Payn, Stephen D. Sebestyen, Andrew R. Zimmerman, Fernando L. Rosario-Ortiz
Patterns in Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) data provide perspective on how organic matter (OM) character is shaped by natural processes. Here, we reevaluate and update the molecular lability boundary (MLB) approach to assess OM lability using a synthesis of FT-ICR MS data. Now included are MLBL (biolability) indices (i.e., the OM proportion of hydrogen-to-carbon
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Molecular fossil chronicles and geochemical probes of Paleogene coals from Meghalaya, India Org. Geochem. (IF 3.0) Pub Date : 2023-08-20 Tushar Adsul, Molly D. O'Beirne, Santanu Ghosh, Josef P. Werne, Devleena Mani, Sudip Bhattacharyya, Atul Kumar Varma
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Geochemistry articles – June, 2023 Org. Geochem. (IF 3.0) Pub Date : 2023-08-10
Abstract not available
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Experimental evidence suggests dominance of species effect on the variability in hydrogen isotope fractionation between leaf wax compounds and source water Org. Geochem. (IF 3.0) Pub Date : 2023-08-03 Amrita Saishree, Shreyas Managave, Vijayananda Sarangi, Prasanta Sanyal
Quantifying the hydrogen isotope fractionation between leaf wax compounds and source water (εapp) is a prerequisite for hydrogen isotopic composition (δD) based paleo-hydrological studies. However, characterization of the εapp values, mostly done in field-based studies, are predominantly carried out in northern mid-latitude regions, as compared to that in the tropics. Further, the εapp values estimated
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Comparing extraction methods for analyzing n-alkyl lipids in shelf sediments from the China Sea Org. Geochem. (IF 3.0) Pub Date : 2023-07-24 Jiaming Zhou, Xiaoxiao Zhao, Xin Chen, Liang Dong
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A GC/C/IRMS-based method for position-specific carbon isotopic analysis of saturated long chain fatty acids Org. Geochem. (IF 3.0) Pub Date : 2023-07-22 Yu Zhao, Ran Ma, Yaoting Qi, Rong He, Zhenyu Zhu, Bo Wang, Ying Wang, Qiulin Yan, Maxime Julien, Youping Zhou
Intramolecular carbon isotope profiles (13C/12C) of mid- and long-chain saturated fatty acids represent a potentially rich source of pathway and flux information on fatty lipid biosynthesis. Accessing the PSIC-13C (position-specific carbon isotope composition) of saturated long chain fatty acids, however, proves a challenge as neither 13C NMR, nor online pyrolysis, can measure all carbons successfully
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Effect of salinity on the preservation of plant-derived n-alkyl compounds in the terrestrial-aquatic interface Org. Geochem. (IF 3.0) Pub Date : 2023-07-22 Santrupta Samantaray, Prasanta Sanyal
In sediments, plant biomolecules (n-alkanes and fatty acids) serve as robust proxies in paleoenvironmental studies. Although the factors controlling preservation and isotopic composition of plant biomolecules are understood in soil systems, the effect of changes in depositional environments in land-sea interfaces, especially in hypersaline environments, is not so well constrained. In this study, we