John M. Eiler’s research while affiliated with Planetary Science Institute and other places

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Publications (596)


Inferring relative sediment fluxes and landscape evolution trends from C, O and clumped isotopes and mineral composition in detrital carbonate
  • Article

December 2024

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12 Reads

Earth and Planetary Science Letters

Ravid Hagbi

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Liran Goren

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John M. Eiler

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Location map of the Ganga and Brahmaputra rivers and the extents of Tethyan‐, Greater‐, and Lesser‐Himalayan thrust sheets. Dots mark the location of sampled bedrock (black), river sediments (white) and Bengal Fan cores (orange) retrieved during IODP expedition 354 (France‐Lanord et al., 2016), and R/V SONNE expedition SO93 (Hübscher et al., 1997). Numbers are TΔ47 (°C) values of detrital calcite in river sediment samples.
Stable isotope measurements of calcite minerals in Himalayan bedrock (gray background), Ganga River sediments (green background) and Bengal Fan turbidite (red background) or hemiplegic/shelf deposits (blue background). Black line is a mixing model prediction between an integrated Himalayan‐bedrock endmember and a river‐authigenic endmember; assuming end‐member values of δ¹⁸O = −14‰, δ¹³C = 0‰ and TΔ47 = 184°C for Himalayan‐bedrock and δ¹⁸O = −10‰ δ¹³C = −2‰ and TΔ47 = 19°C for authigenic calcite. Numbers are the percent of the latter component. (a) TΔ47 versus δ¹⁸O; and (b) TΔ47 versus δ¹³C.
(a) TΔ47 values of detrital calcite in Bay of Bengal turbidite deposits. (b) Calcite and total carbonate contents in turbidite deposits of IODP 354 cores based on acetic acid leaching (Tachambalath et al., 2023, red dots), and coulometry (France‐Lanord et al., 2016, cyan dots), respectively. (c) Weathering intensity proxy K/Si* calculated after Lupker et al. (2012) from bulk sediment XRF measurements in turbidite deposits of IODP 354 cores (France‐Lanord et al., 2016). Depositional ages in A–C are from, Reilly et al. (2020), Lenard et al. (2020) and Cruz et al. (2021). Gray rectangle marks the proposed interval in which Lesser Himalaya became a significant source for detrital carbonate in Himalayan river systems.
Carbonate clumped isotope temperatures of detrital calcite in Miocene‐Holocene turbidite deposits in the Bengal Fan plotted versus calcite/Σcarbonate ratio. Gray line is model prediction for the effect of changing Himalayan carbonate bedrock provenance from 100% Tethyan and Greater Himalaya at the Early Miocene to 63% Tethyan Himalaya and 37% Lesser Himalaya at the Present. Mixing model details are available in Note S1 in Supporting Information S1.
Late Miocene Uplift and Exhumation of the Lesser Himalaya Recorded by Clumped Isotope Compositions of Detrital Carbonate
  • Article
  • Full-text available

November 2024

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183 Reads

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1 Citation

U. Ryb

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[...]

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J. M. Eiler

The Himalaya orogen evolved since the Eocene as the Tethyan‐, Greater‐, Lesser‐ and Sub‐Himalaya thrust sheets were uplifted and exhumed in sequence. Reconstructing the provenance of sediment in Himalayan River systems can inform on stages in the tectonic history of the orogen. Here, we analyze the oxygen, carbon and “clumped” isotope compositions of carbonate minerals from Himalayan bedrock, Ganga River sediments and Bengal Fan turbidite deposits. We demonstrate that river sediments consist of a mixture of Himalayan‐derived and authigenic calcite precipitated in the river system. The relative abundance and clumped isotope apparent temperatures of detrital calcite in turbidite deposits decreased between the Late Miocene and Pliocene, while chemical weathering intensity did not increase during this interval. Considered together, these results reflect the establishment of the Lesser Himalaya as an important carbonate sediment source for Himalayan rivers, driven by the uplift and exhumation of this thrust sheet.

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Acetate exchanges hydrogen isotopes with water at a temperature-dependent rate
A Arrhenius plot of hydrogen isotope exchange rates with a linear regression through experiments at 60 °C (n = 3), 100 °C (n = 1), 150 °C (n = 2) and 200 °C (n = 2) (solid circles). Extrapolated reaction rates are projected to 25 °C (open circle). Shaded region represents 2 RMSD. B Carbon and hydrogen isotope composition of acetate from Kidd Creek and Birchtree mines. Shaded regions represent δ¹³C of total organic carbon from the metasedimentary rocks of the Kidd Creek formation³⁴. Error bars reflect standard deviation on analytical triplicates.
Theoretical calculations and empirical results confirm that acetate in subsurface fracture fluids is in isotopic disequilibrium with the ambient water
A Observed isotope effect between acetate and water throughout a three-day 200 °C exchange experiment with water at either −50‰ or +110‰. Dashed line represents the calculated EIE between acetate and pure water. Error bars represent standard deviation on analytical replicates (n = 3). B Hydrogen isotope fractionation between acetate and water (²εacetate/water) at both sites. Solid line is the calculated EIE between the Ca-acetate complex and brine water. Dashed line is the EIE between free acetate and brine water as a function of temperature. Error bars are covered by the data points and represent standard deviation on analytical replicates (n = 3).
Acetate cycling could theoretically support microbial communities in the continental subsurface
Theoretical cell densities for sulfate reducers (left) and acetoclastic methanogens (right) that could be supported in the fracture fluids over a range of acetate production rates.
Isotopic evidence of acetate turnover in Precambrian continental fracture fluids

October 2024

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191 Reads

The deep continental crust represents a vast potential habitat for microbial life where its activity remains poorly constrained. Organic acids like acetate are common in these ecosystems, but their role in the subsurface carbon cycle - including the mechanism and rate of their turnover - is still unclear. Here, we develop an isotope-exchange ‘clock’ based on the abiotic equilibration of H-isotopes between acetate and water, which can be used to define the maximum in situ acetate residence time. We apply this technique to the fracture fluids in Birchtree and Kidd Creek mines within the Canadian Precambrian crust. At both sites, we find that acetate residence times are <1 million years and calculated a rate of turnover that could theoretically support microbial life. However, radiolytic water-rock reactions could also contribute to acetate production and degradation, a process that would have global relevance for the deep biosphere. More broadly, our study demonstrates the utility of isotope-exchange clocks in determining residence times of biomolecules with possible applications to other environments.


Fig. 1. Map showing (a) global coal bed methane resources and the location of southern Qinshui Basin and (b) the CBM sampling sites in this study. The CBM resource data in (a) from previous studies (see in Supplementary Text 1). The Tcm represents trillion m3. PZ and ZH represent the Panzhuang and Zhengzhuang block, respectively.
Fig. 2. Genetic diagrams of CBM from Qinshui. (a). Methane bulk isotope compositions, δ13C-CH4vs. δD-CH4 (b). C1/(C2 + C3) vs. δ13C-CH4. (c). δ13C-CO2 vs. δ13CCH4. (d). Hydrogen isotope fractionation between methane and water (DεCH4(g)-H2O(l), also reported as εmethane/water) vs. carbon isotope fractionation between methane and CO2 (13εCH4(g)-CO2(g)). The gas genetic fields in a–d are from Bernard et al. (1976), Whiticar (1999), Milkove and Etiope (2018) and Whiticar (2020) with standardized notations (SM—secondary microbial, biod.—biodegradation, CR–CO2 reduction, F—methyl-type fermentation). The primary microbial including methyl-type fermentation and CO2 reduction. The solid black curve in (d) represents 13ε and Dε thermodynamic isotopic equilibrium from Turner et al. (2021); Turner et al. (2022). The methane bulk isotopes of δ13C and δD are reported in the Vienna Peedee belemnite (VPDB) and Vienna standard mean ocean water (VSMOW) reference framework.
Fig. 3. Methane clumped isotope compositions in Qinshui Basin and other natural gas reservoirs. The black line represents the calculated thermodynamic equilibrium of dual methane isotopologues (Young et al., 2017). The shaded cross represents the equilibrium clumped isotopic ranges at the ambient temperatures (coal bed water: 16.0–35.5 ◦C). Error bars are shown in 1σ level of uncertainty. Other natural gas data from previous studies (see in Supplementary Text 4).
Fig. 4. Relationship between CBM production and microbial contribution. (a). Δ12CH2D2vs. Δ13CH3D plot with microbial contribution and gas production as variables. (b). Gas production vs. CBM microbial contribution from Qinshui Basin. A negative correlation (r2 = 0.72, p = 0.002) between microbial contribution and annual gas production is observed. The gray bands are the 95 % confidence and prediction interval for the linear regression.
Clumped isotopes constrain thermogenic and secondary microbial methane origins in coal bed methane

October 2024

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194 Reads

Earth and Planetary Science Letters

Methane is an economic energy resource and potent greenhouse gas. Distinguishing secondary microbial methane from thermogenic gas is important for natural gas exploration and consideration of subsurface microbial activity in the global carbon cycle, but remains challenging. To understand controls on methane origins in natural gas systems, we investigated the methane clumped isotopologue distributions in the Qinshui Basin high-thermal maturity coal bed methane (CBM) reservoir. Here, near-equilibrium clumped isotopologues distribution (Δ13CH3D and Δ12CH2D2) inferred a temperature interval of 21.6–252.3 °C. The high-temperature thermodynamic equilibrium most likely represents original thermogenic CBM characteristics during coalification. The low-temperature equilibrium clumped isotopologue distributions suggest microbial alteration to CH4 isotopic bond ordering by increased enzymatically catalyzed isotopic exchange. The independent constraints from clumped isotopes, integrated with other geochemical and genomic evidence, confirm notable secondary microbial methane from biodegradation in the highly mature reservoir. Thus, methane clumped isotopes can be used as unequivocal tracers to distinguish secondary microbial methane from thermogenic gases and hence provide the ability to incorporate them separately into global methane budgets.



Reconstruction of Phanerozoic climate using carbonate clumped isotopes and implications for the oxygen isotopic composition of seawater

August 2024

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285 Reads

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1 Citation

Proceedings of the National Academy of Sciences

The oxygen isotope ratio ¹⁸ O/ ¹⁶ O (expressed as a δ ¹⁸ O VSMOW value) in marine sedimentary rocks has increased by ~8‰ from the early Paleozoic to modern times. Interpretation of this trend is hindered by ambiguities in the temperature of formation of the carbonate, the δ ¹⁸ O seawater , and the effects of postdepositional diagenesis. Carbonate clumped isotope measurements, a temperature proxy, offer constraints on this problem. This thermometer is thermodynamically controlled in cases where carbonate achieves an equilibrium internal distribution of isotopes and is independent of the δ ¹⁸ O of the water from which the carbonate grew; therefore, it has a relatively rigorous chemical–physics foundation and can be applied to settings where the δ ¹⁸ O of the water is not known. We apply this technique to an exceptionally well-preserved Ordovician carbonate record from the Baltic Basin and present a framework for interpreting clumped isotope results and for reconstructing past δ ¹⁸ O seawater . We find that the seawater in the Ordovician had lower δ ¹⁸ O seawater values than previously estimated, highlighting the need to reassess climate records based on oxygen-isotopes, particularly where interpretations are based on assumptions regarding either the δ ¹⁸ O seawater or the temperature of deposition or diagenesis. We argue that an increase in δ ¹⁸ O seawater contributed to the long-term rise in the δ ¹⁸ O of marine sedimentary rocks since the early Paleozoic. This rise might have been driven by a change in the proportion of high- versus low-temperature water–rock interaction in the earth’s hydrosphere as a whole.



Fig. 4 | Evidence for aqueous alteration of the asteroid Ryugu revealed by dicarboxylic acids and molecular tautomerism of malonic acid. A Dicarboxylic acid profiles (i.e., C 2 , oxalic acid; C 3 , malonic acid; C 4 , succinic acid; C 5 , glutaric acid; C 6 , aspartic acid; C 7 , pimelic acid; and C 8 , suberic acid) for the Ryugu (A0106 and C0107) and CM types (Murchison and Murray) normalized by oxalic acid as 100%.
Fig. 6 | Summary of integrated observations of Ryugu with CI type (Ivuna) and CM type (Murchison and Murray) for aqueous alteration processes throughout their history. A Hydroxy acids, dicarboxylic and tricarboxylic acids, and other newly identified hydrophilic molecules for comparison between Ryugu (this study) and CM (Murchison and Murray; this study) type at the ppb scale. The Ryugu values on the horizontal axis are shown as the average of A0106 and C0107 (Table S1). B Amino acids for the comparison between CI type (Ivuna) and CM type (Murchison and Murray) based on compilation 39 . Please see the individual molecular
Fig. 7 | Carbon, nitrogen, hydrogen and sulfur abundances and their isotopic profiles before and after the solvent extraction processes from the organic matter facies. A The 15 N-nitrogen isotopic depletion between the supernatant and IOM residue during sequential solvent extraction for the Ryugu (A0106 and C0107) and Orgueil samples. The pinkish color originates from formic acid extract #9, and the yellowish color originates from HCl extract #10. The other chemical profiles are shown in Figs. S6, S7, and S8. Please also see the residue of IOM (black color) on the bottom of the vial 78 . Unique brownish colloidal-colored fractions (#4 MeOH extract, #5 water extract) were observed for A0106 and C0107 (cf. Figs. S5, S9).
Fig. 8 | Aqueous alteration of primordial hydrophilic organic molecules and minerals during parent body processing of asteroid (162173) Ryugu. The left panel represents the initial primary mineral assemblage and fluid veins in the early stage of interaction between water, organics, and rock within the bedrock. The right panel represents altered secondary mineral assemblages (i.e., porous and physically fragile), desiccated veins, and precipitates in the late stage and ongoing stage with dehydration processes at Ryugu 47,50 . Within cold hydrothermalism 15 ,
Fig. 9 | Photographs showing representative altered aqueous signatures, desiccated veins, and spatial cross-sections of Ryugu samples. A Representative photographs of the chamber A sample series and (B) chamber C sample series, showing the cross-sectional areas that are past fluid veins and/or hydrothermally
Primordial aqueous alteration recorded in water-soluble organic molecules from the carbonaceous asteroid (162173) Ryugu

July 2024

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218 Reads

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3 Citations

We report primordial aqueous alteration signatures in water-soluble organic molecules from the carbonaceous asteroid (162173) Ryugu by the Hayabusa2 spacecraft of JAXA. Newly identified low-molecular-weight hydroxy acids (HO-R-COOH) and dicarboxylic acids (HOOC-R-COOH), such as glycolic acid, lactic acid, glyceric acid, oxalic acid, and succinic acid, are predominant in samples from the two touchdown locations at Ryugu. The quantitative and qualitative profiles for the hydrophilic molecules between the two sampling locations shows similar trends within the order of ppb (parts per billion) to ppm (parts per million). A wide variety of structural isomers, including α- and β-hydroxy acids, are observed among the hydrophilic molecules. We also identify pyruvic acid and dihydroxy and tricarboxylic acids, which are biochemically important intermediates relevant to molecular evolution, such as the primordial TCA (tricarboxylic acid) cycle. Here, we find evidence that the asteroid Ryugu samples underwent substantial aqueous alteration, as revealed by the presence of malonic acid during keto–enol tautomerism in the dicarboxylic acid profile. The comprehensive data suggest the presence of a series for water-soluble organic molecules in the regolith of Ryugu and evidence of signatures in coevolutionary aqueous alteration between water and organics in this carbonaceous asteroid.



Fig. 1. N 2 O production via NO detoxification under anoxic conditions may explain environmental SP values. (A) Measured in situ SP values for environmental sources (Soil, Marine, Freshwater) vs. in vitro measurements of N 2 O-producing biogenic end-members (bacterial and fungal denitrification, AOB, AOA) and N 2 O-producing abiotic reactions; black line shows median; blue lines show end-member values for AOB (8). Histogram height is normalized to each category; see SI Appendix, Fig. S11 for outlier values and more details. (B) Number of bacterial genomes hits at the phylum level for flavohemoglobin protein (Fhp) and nitrous oxide reductase (NorBC) alone or in combination from Annotree (9); minimum amino acid sequence similarity of 30% was used. See SI Appendix, Fig. S1 and Tables S2 and S3 for phylogenetic distribution. (C) Relevant N-oxide pathways of P. aeruginosa UCBPP-PA14 (Pa), the model organism used in this study. Pa possesses the full denitrification pathway as well as Fhp. (D) SP of N 2 O produced by Pa and mutant strains with fhp and/or nosZ genes deleted (ΔnosZΔfhp; ΔnosZ) in denitrifying conditions sampled at late-exponential or late-stationary growth phases; see SI Appendix, Fig. S2 for more details. (E) N 2 O SP of Pa strains with rhamnose-induced expression of norBCD (iNOR) or fhp (iFhp) alone as well as A. baumannii and S. aureus, which only have Fhp. P value was calculated via Welch's t test. Each data point in (D and E) represents an individual biological replicate.
Widespread detoxifying NO reductases impart a distinct isotopic fingerprint on N2O under anoxia

June 2024

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11 Reads

Proceedings of the National Academy of Sciences

Nitrous oxide (N 2 O), a potent greenhouse gas, can be generated by multiple biological and abiotic processes in diverse contexts. Accurately tracking the dominant sources of N 2 O has the potential to improve our understanding of N 2 O fluxes from soils as well as inform the diagnosis of human infections. Isotopic “Site Preference” (SP) values have been used toward this end, as bacterial and fungal nitric oxide reductases (NORs) produce N 2 O with different isotopic fingerprints, spanning a large range. Here, we show that flavohemoglobin (Fhp), a hitherto biogeochemically neglected yet widely distributed detoxifying bacterial NO reductase, imparts a distinct SP value onto N 2 O under anoxic conditions (~+10‰) that correlates with typical environmental N 2 O SP measurements. Using Pseudomonas aeruginosa as a model organism, we generated strains that only contained Fhp or the dissimilatory NOR, finding that in vivo N 2 O SP values imparted by these enzymes differ by over 10‰. Depending on the cellular physiological state, the ratio of Fhp:NOR varies significantly in wild-type cells and controls the net N 2 O SP biosignature: When cells grow anaerobically under denitrifying conditions, NOR dominates; when cells experience rapid, increased nitric oxide concentrations under anoxic conditions but are not growing, Fhp dominates. Other bacteria that only make Fhp generate similar N 2 O SP biosignatures to those measured from our P. aeruginosa Fhp-only strain. Fhp homologs in sequenced bacterial genomes currently exceed NOR homologs by nearly a factor of four. Accordingly, we suggest a different framework to guide the attribution of N 2 O biological sources in nature and disease.


Citations (60)


... The maximum percentage of Tethys Himalayan detritus is identified in Upper Miocene strata, which is supported by the positive correlation between the percentage of carbonate content and the percentage of δ 18 O values >16 ‰ in turbidites (Fig. 4). This fully supports more significative supply from the Tethys Himalaya to Bengal Fan during the Late and Middle Miocene than during the Pliocene-Pleistocene, already documented by the higher detrital carbonate content of the Upper and Middle Miocene turbidites (Ryb et al., 2024;France-Lanord et al., 2016). No relationship is observed instead between Sr -Nd values and single-grain quartz δ 18 O values (Supplementary Figure S6ab). ...

Reference:

Single quartz δ18O: A new frontier in detrital provenance analysis (Bengal Fan, IODP Expedition 354)
Late Miocene Uplift and Exhumation of the Lesser Himalaya Recorded by Clumped Isotope Compositions of Detrital Carbonate

... parent body 21 compared with Bennu's, leading to their evaporation and/ or more extensive aqueous alteration, ultimately decomposing or altering carboxylic acids 28 . The structural diversity of carboxylic acids in Bennu is consistent with an origin through stochastic low-temperature free radical reactions on interstellar dust grains 26 . ...

Primordial aqueous alteration recorded in water-soluble organic molecules from the carbonaceous asteroid (162173) Ryugu

... To address these important scientific questions, the Hayabusa2 soluble organic matter (SOM) team 6 evaluated aggregate fine grain samples from the first and second touchdown sites (hereafter, TD1 and TD2); hence, the bulk chemistry data from these two sample collections are averaged representative values for the surface (A0106) and possibly subsurface (C0107) environments (i.e., TD2 was near the artificial crater, for which the depth was~1.7 meters below ground level 8 ) of Ryugu (Fig. 1). For further insight at the organic molecular level, the SOM team determined the first answers to these questions based on carbon (C), nitrogen (N), hydrogen (H), oxygen (O), sulfur (S) elements and their isotopic profiles 6,9,10 , monocarboxylic acids 6 , amino acids and their molecular chirality 6,11,12 , pyrimidine nucleobase and N-heterocycles 6,9 , primordial salts and sulfur-bearing labile molecules between the organic and inorganic interfaces 10 , aliphatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) 13,14 , comprehensive organic molecular profiles 6,15 , molecular growth signatures 16 , and sub-mm scale spatial imaging for organic homogeneity and heterogeneity in the mineral assemblage 6,17 . According to Fourier transform-ion cyclotron resonance mass spectrometry (FT-ICR/MS) analysis, the SOM from Ryugu samples contained highly diverse organic molecules (~20,000 species) in the solvent extracts 6,15 . ...

Enantioselective three-dimensional high-performance liquid chromatographic determination of amino acids in the Hayabusa2 returned samples from the asteroid Ryugu

Journal of Chromatography Open

... Observations of Io at (sub)millimeter wavelengths previously revealed the distribution of SO 2 , SO, and alkali gases using a variety of single-dish and interferometric facilities (Lellouch et al., 1990(Lellouch et al., , 1992(Lellouch et al., , 1996(Lellouch et al., , 2003Moullet et al., 2010Moullet et al., , 2013Roth et al., 2020;de Pater et al., 2020;Redwing et al., 2022;de Kleer et al., 2024). Moullet et al. (2008) made the first direct measurements of atmospheric winds in Io's SO 2 using the Institut de Radioastronomie Millimétrique (IRAM) Plateau de Bure Interferometer (PdBI). ...

Isotopic evidence of long-lived volcanism on Io
  • Citing Article
  • April 2024

Science

... While observations are at a relatively low spatial resolution (~350 km/pixel in the near-IR and~750 km/pixel in the mid-IR), infrared spectra have been obtained from 0.7 to 5.3 µm at high spectral resolution (λ/Δλ =~3000), obtaining spectra of gas emission from Io's most powerful volcanoes (de Pater et al. 2023). The Atacama Large (sub-)Millimeter Array (ALMA) can map molecular species in Io's atmosphere with high sensitivity to trace the composition of Io's bulk atmosphere as well as in plumes (de Pater et al. 2020;Redwing et al. 2022;de Kleer et al. 2024); planned upgrades to ALMA in the upcoming decades will increase its ability to map many species simultaneously, and may improve its sensitivity, which would enable detection of new species. ...

Using Io's Sulfur Isotope Cycle to Understand the History of Tidal Heating

... In recent years, many scholars have found that CBM can be produced by in situ microorganisms in coal (Tao et al. 2007;Flores et al. 2008;Hamilton et al. 2014;Sechman et al. 2017). The formation and accumulation of biogenic methane in coal seams results from a series of biogeochemical processes facilitated by microorganisms , which are manifested as the synergistic action of living bacteria or fungi and archaea within three major metabolic steps (Susilawati et al. 2015):(1) hydrolysis and fermentation bacteria degrade large components of coal into small molecules, such as fatty acids; (2) vinegar-producing bacteria convert fatty acids, alcohols, some aromatics and amino acids into acetic acid, methanol, H 2 and CO 2 ; (3) simple molecules such as acetic acid are subsequently converted to CH 4 by methanogenic archaea (Wang et al. 2024). Certain methanogenic thermophilic micrococci can directly convert methoxyaromatic compounds (MACs) from coal to CH 4 (Akimbekov et al. 2024). ...

Biogenic methane clumped isotope signatures: Insights from microbially enhanced coal bed methane
  • Citing Article
  • March 2024

Fuel

... In carbonaceous chondrites, insoluble organic matter (IOM) accounts for 70% of all organic matter [39]. Its origin, besides interstellar radical synthesis, might be related to impact-induced reduction reactions, promoted by metal droplets or minerals [40,41]. These metals could act as reductive agents, originating reduced forms of organic matter (e.g., aromatic rings, extensive conjugation, and CO 2 reduction) [42,43]. ...

Polycyclic aromatic hydrocarbons in samples of Ryugu formed in the interstellar medium
  • Citing Article
  • December 2023

Science

... The supersonic expansion technique introduced the gas-phase molecular complexes into the spectrometer, forming a supersonic molecular beam crucial for well-defined rotational spectra Nasrollahzadeh et al., 2018). Pulsed microwave excitation-induced rotational transitions, and Fourier Transform Infrared (FTIR) detection probed the resulting molecular states, providing information about vibrational and rotational characteristics (Chimiak & Eiler, 2024;Mani, 2018;. The high-resolution capabilities of the PNFTIR spectrometer, both in the time and frequency domains, enabled precise determination of transition frequencies and intensities (Shinggu et nozzle Fourier transform microwave spectroscopy and computational analysis. ...

Prebiotic synthesis on meteorite parent bodies: Insights from hydrogen and carbon isotope models
  • Citing Article
  • November 2023

Chemical Geology

... Δ 47-CDES25 = 0.655 ‰ for TV04 and Δ 47-CDES25 = 0.405 ‰ for Carrara (Mangenot et al., 2024). The error related to the standards was used (± 0.014 ‰, 1σ) for samples without 3 replicates. ...

Diagenetic history of calcite fractures in Vaca Muerta shales (Argentina) inferred from paired Δ47 and fluid inclusion geothermometry
  • Citing Article
  • November 2023

Marine and Petroleum Geology

... It could therefore aid in the identification of potential terrestrial contaminants in samples brought back to Earth. Current research also focuses on utilizing ultrahigh-resolution mass spectrometry for stable isotope analysis of larger molecules ( 34 ) providing the possibility for reconstruction of positionspecific and multiply substituted (clumped) isotope abundances, which can give critical insights into the origins of organic materials. ...

Natural Abundance Isotope Ratio Measurements of Organic Molecules Using 21 T FTICR MS
  • Citing Article
  • November 2023

Analytical Chemistry