Pub Date : 2025-02-01DOI: 10.1016/j.orggeochem.2024.104902
Minkai Du , Miao Li , Weijie Liu , Mingming Shi , Xiaoqian Li , Xinli Xing , Shihua Qi
Soil and groundwater pollution from industrial and agricultural activities has become a global concern. This study therefore investigates the occurrence, sources, and transport mechanisms of polycyclic aromatic hydrocarbons (PAHs) in the soil-groundwater system of a closed refinery. Field investigations and laboratory column experiments revealed widespread PAH contamination in both groundwater and soil, with higher concentrations near the groundwater level (6.45–8.75 m). PAHs in soil and groundwater were predominantly low and medium molecular weight compounds (LMW and MMW), originated from petroleum leakage and coal combustion. The region’s soil, primarily composed of loess and gravel with low total organic carbon (TOC) content (mean 0.07%), showed a positive correlation between PAH concentration and TOC/clay content, while sand content had no significant impact. Groundwater fluctuations influence PAH accumulation at the soil-groundwater interface (SGI), which may suggest potential for increased migration under varying hydraulic conditions. This vertical migration offers new insights into contaminant transport models in groundwater systems, particularly for arid regions, and could inform future remediation strategies for similar contamination scenarios.
{"title":"Field and laboratory study on the distribution, fate and transport of polycyclic aromatic hydrocarbons in the loess porous medium at a refinery polluted site: Understanding the soil-groundwater interface","authors":"Minkai Du , Miao Li , Weijie Liu , Mingming Shi , Xiaoqian Li , Xinli Xing , Shihua Qi","doi":"10.1016/j.orggeochem.2024.104902","DOIUrl":"10.1016/j.orggeochem.2024.104902","url":null,"abstract":"<div><div>Soil and groundwater pollution from industrial and agricultural activities has become a global concern. This study therefore investigates the occurrence, sources, and transport mechanisms of polycyclic aromatic hydrocarbons (PAHs) in the soil-groundwater system of a closed refinery. Field investigations and laboratory column experiments revealed widespread PAH contamination in both groundwater and soil, with higher concentrations near the groundwater level (6.45–8.75 m). PAHs in soil and groundwater were predominantly low and medium molecular weight compounds (LMW and MMW), originated from petroleum leakage and coal combustion. The region’s soil, primarily composed of loess and gravel with low total organic carbon (TOC) content (mean 0.07%), showed a positive correlation between PAH concentration and TOC/clay content, while sand content had no significant impact. Groundwater fluctuations influence PAH accumulation at the soil-groundwater interface (SGI), which may suggest potential for increased migration under varying hydraulic conditions. This vertical migration offers new insights into contaminant transport models in groundwater systems, particularly for arid regions, and could inform future remediation strategies for similar contamination scenarios.</div></div>","PeriodicalId":400,"journal":{"name":"Organic Geochemistry","volume":"200 ","pages":"Article 104902"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176263","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}
Pub Date : 2025-02-01DOI: 10.1016/j.orggeochem.2024.104922
Lauren K. Olinger , Wendy K. Strangman , Steven E. McMurray , Ralph N. Mead , Joseph R. Pawlik
With the decline of reef-building corals, other organisms are taking over Caribbean reefs, including sponges and benthic cyanobacterial mats (BCM). Sponges take up dissolved organic matter (DOM), but the sources and chemical characteristics of DOM taken up by sponges are unknown. One likely DOM source is benthic autotrophs, including BCM, which are prolific producers of DOM. We tested the hypothesis that sponges take up BCM-derived DOM using laboratory experiments in which seawater samples were collected before and after sequential incubations of BCM and small individuals of the giant barrel sponge Xestospongia muta. The concentration of DOC and relative abundance of individual features in the high resolution mass spectra using untargeted metabolomics were determined for each sample. There was a significant increase in DOC after BCM incubations, followed by a significant decrease after sponge incubations. These changes were mirrored in single feature relative abundances, with 2101 out of 3667 features significantly enriched during BCM incubations, and 54% of these (1142) depleted during sponge incubations. Among BCM-enriched and sponge-depleted features, many were halogenated, some were known BCM-derived secondary metabolites (e.g., carriebowmide, barbamide), and others matched unidentified sponge-depleted features from seawater samples collected on the reef. To our knowledge, this is the first report that sponges take up BCM exudates, including some that were detectable in reef DOM, revealing a path of molecules from source to sink through their environment. The BCM exudates taken up by sponges may be used as a food source or incorporated into sponge secondary metabolites for holobiont maintenance or chemical defenses.
{"title":"The giant barrel sponge Xestospongia muta takes up dissolved organic matter from benthic cyanobacterial mats","authors":"Lauren K. Olinger , Wendy K. Strangman , Steven E. McMurray , Ralph N. Mead , Joseph R. Pawlik","doi":"10.1016/j.orggeochem.2024.104922","DOIUrl":"10.1016/j.orggeochem.2024.104922","url":null,"abstract":"<div><div>With the decline of reef-building corals, other organisms are taking over Caribbean reefs, including sponges and benthic cyanobacterial mats (BCM). Sponges take up dissolved organic matter (DOM), but the sources and chemical characteristics of DOM taken up by sponges are unknown. One likely DOM source is benthic autotrophs, including BCM, which are prolific producers of DOM. We tested the hypothesis that sponges take up BCM-derived DOM using laboratory experiments in which seawater samples were collected before and after sequential incubations of BCM and small individuals of the giant barrel sponge <em>Xestospongia muta</em>. The concentration of DOC and relative abundance of individual features in the high resolution mass spectra using untargeted metabolomics were determined for each sample. There was a significant increase in DOC after BCM incubations, followed by a significant decrease after sponge incubations. These changes were mirrored in single feature relative abundances, with 2101 out of 3667 features significantly enriched during BCM incubations, and 54% of these (1142) depleted during sponge incubations. Among BCM-enriched and sponge-depleted features, many were halogenated, some were known BCM-derived secondary metabolites (e.g., carriebowmide, barbamide), and others matched unidentified sponge-depleted features from seawater samples collected on the reef. To our knowledge, this is the first report that sponges take up BCM exudates, including some that were detectable in reef DOM, revealing a path of molecules from source to sink through their environment. The BCM exudates taken up by sponges may be used as a food source or incorporated into sponge secondary metabolites for holobiont maintenance or chemical defenses.</div></div>","PeriodicalId":400,"journal":{"name":"Organic Geochemistry","volume":"200 ","pages":"Article 104922"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176286","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}
Pub Date : 2025-02-01DOI: 10.1016/j.orggeochem.2025.104928
Felipe Stanchak , Julie N. Richey , Amanda Gerotto , Amelia Shevenell , Marcia C. Bícego , Felipe A. Toledo , Michel M. de Mahiques , Renata H. Nagai
The paleothermometer based on the alkenone unsaturation index () is often used to reconstruct past sea surface temperatures (SST). In the SW Atlantic Ocean, however, a limited understanding of the seasonal and depth distribution of coccolithophores, which generates the signal preserved in ocean sediments, hinders accurate estimates of past regional SSTs. We analyzed 45 core-top sediment samples from the continental shelf of the South Brazilian Bight (SBB, 23 °S to 28 °S) to assess regional spatial -SST gradients and improve SST estimates. The data were converted to SST using six published paleotemperature equations and compared to modern observational SST data from the World Ocean Atlas (2018) data set. Data indicate that the signal is produced during the austral summer and autumn when regional episodic upwelling events occur over the inner-shelf and the nutricline shoals at the slope. Our analysis of core-top data shows that SST estimates derived from most calibration equations closely align with modern observed temperatures but are skewed toward warmer months associated with upwelling-derived nutrients. Our findings underscore the importance of considering regional and seasonal biases to improve the accuracy of paleotemperature reconstructions. Understanding the factors influencing the SBB signal enables a more meaningful comparison between regional paleoceanographic studies, improving our understanding of past changes in the SW Atlantic Ocean and our ability to predict regional SST response to ongoing and future warming.
{"title":"Validation of the U37K′ paleotemperature proxy in the South Brazilian Bight from core-top sediments","authors":"Felipe Stanchak , Julie N. Richey , Amanda Gerotto , Amelia Shevenell , Marcia C. Bícego , Felipe A. Toledo , Michel M. de Mahiques , Renata H. Nagai","doi":"10.1016/j.orggeochem.2025.104928","DOIUrl":"10.1016/j.orggeochem.2025.104928","url":null,"abstract":"<div><div>The paleothermometer based on the alkenone unsaturation index (<span><math><msubsup><mtext>U</mtext><mrow><mtext>37</mtext></mrow><msup><mrow><mtext>K</mtext></mrow><mo>′</mo></msup></msubsup></math></span>) is often used to reconstruct past sea surface temperatures (SST). In the SW Atlantic Ocean, however, a limited understanding of the seasonal and depth distribution of coccolithophores, which generates the <span><math><msubsup><mtext>U</mtext><mrow><mtext>37</mtext></mrow><msup><mrow><mtext>K</mtext></mrow><mo>′</mo></msup></msubsup></math></span> signal preserved in ocean sediments, hinders accurate estimates of past regional SSTs. We analyzed 45 core-top sediment samples from the continental shelf of the South Brazilian Bight (SBB, 23 °S to 28 °S) to assess regional spatial <span><math><msubsup><mtext>U</mtext><mrow><mtext>37</mtext></mrow><msup><mrow><mtext>K</mtext></mrow><mo>′</mo></msup></msubsup></math></span>-SST gradients and improve SST estimates. The <span><math><msubsup><mtext>U</mtext><mrow><mtext>37</mtext></mrow><msup><mrow><mtext>K</mtext></mrow><mo>′</mo></msup></msubsup></math></span> data were converted to SST using six published paleotemperature equations and compared to modern observational SST data from the World Ocean Atlas (2018) data set. Data indicate that the <span><math><msubsup><mtext>U</mtext><mrow><mtext>37</mtext></mrow><msup><mrow><mtext>K</mtext></mrow><mo>′</mo></msup></msubsup></math></span> signal is produced during the austral summer and autumn when regional episodic upwelling events occur over the inner-shelf and the nutricline shoals at the slope. Our analysis of core-top data shows that SST estimates derived from most calibration equations closely align with modern observed temperatures but are skewed toward warmer months associated with upwelling-derived nutrients. Our findings underscore the importance of considering regional and seasonal biases to improve the accuracy of paleotemperature reconstructions. Understanding the factors influencing the SBB <span><math><msubsup><mtext>U</mtext><mrow><mtext>37</mtext></mrow><msup><mrow><mtext>K</mtext></mrow><mo>′</mo></msup></msubsup></math></span> signal enables a more meaningful comparison between regional paleoceanographic studies, improving our understanding of past changes in the SW Atlantic Ocean and our ability to predict regional SST response to ongoing and future warming.</div></div>","PeriodicalId":400,"journal":{"name":"Organic Geochemistry","volume":"200 ","pages":"Article 104928"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176265","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}
Pub Date : 2025-02-01DOI: 10.1016/j.orggeochem.2024.104899
Yuqi Wu , Tao Hu , Fujie Jiang , Jing Guo , Feilong Wang , Zhenguo Qi , Renda Huang , Zhou Fang , Xiaowei Zheng , Di Chen
The Paleocene-Eocene thermal maximum (PETM, ∼ 56 Ma) was driven by global carbon release and temperature increases. Studies of marine strata have indicated that volcanic activity during the PETM led to significant carbon emissions. However, the impact of volcanic activity on terrestrial strata and whether this activity was regional remain unclear. Here, we conducted astrochronological analysis, polycyclic aromatic hydrocarbons (PAHs) analysis, organic petrological identification, and paleo-environmental proxies to identify lacustrine records of PETM from the Miaoxi Depression in the Bohai Bay Basin, eastern China. The analysis of natural gamma-ray (GR) series indicates that PETM occurred at 56.06 Ma and lasted approximately 0.58 Ma within the formation. Significant GR series changes, carbon isotope excursions, and red bed sedimentation were observed during the PETM. Paleo-environmental proxy changes, including decreased paleo-productivity, arid paleo-climate, increased paleo-salinity that promoted strongly reducing conditions, and decreased lake level, were correlated with the GR series and δ13CVPDB excursions. The duration of the PETM event suggests that terrigenous sediments may record climate events in great detail. The PETM corresponds to a peak in 405 kyr eccentricity, but other changes in the astronomical cycle do not align with the paleo-environment data, indicating that astronomical forcing may not be the primary driver of the PETM. Increased PAHs and volcanic proxies suggest enhanced volcanic activity during this period, indicating that the PETM event was associated with regional volcanic activity.
{"title":"Lacustrine records of Paleocene-Eocene Thermal Maximum (PETM) triggered by volcanic activity","authors":"Yuqi Wu , Tao Hu , Fujie Jiang , Jing Guo , Feilong Wang , Zhenguo Qi , Renda Huang , Zhou Fang , Xiaowei Zheng , Di Chen","doi":"10.1016/j.orggeochem.2024.104899","DOIUrl":"10.1016/j.orggeochem.2024.104899","url":null,"abstract":"<div><div>The Paleocene-Eocene thermal maximum (PETM, ∼ 56 Ma) was driven by global carbon release and temperature increases. Studies of marine strata have indicated that volcanic activity during the PETM led to significant carbon emissions. However, the impact of volcanic activity on terrestrial strata and whether this activity was regional remain unclear. Here, we conducted astrochronological analysis, polycyclic aromatic hydrocarbons (PAHs) analysis, organic petrological identification, and paleo-environmental proxies to identify lacustrine records of PETM from the Miaoxi Depression in the Bohai Bay Basin, eastern China. The analysis of natural gamma-ray (GR) series indicates that PETM occurred at 56.06 Ma and lasted approximately 0.58 Ma within the formation. Significant GR series changes, carbon isotope excursions, and red bed sedimentation were observed during the PETM. Paleo-environmental proxy changes, including decreased paleo-productivity, arid paleo-climate, increased paleo-salinity that promoted strongly reducing conditions, and decreased lake level, were correlated with the GR series and δ<sup>13</sup>C<sub>VPDB</sub> excursions. The duration of the PETM event suggests that terrigenous sediments may record climate events in great detail. The PETM corresponds to a peak in 405 kyr eccentricity, but other changes in the astronomical cycle do not align with the paleo-environment data, indicating that astronomical forcing may not be the primary driver of the PETM. Increased PAHs and volcanic proxies suggest enhanced volcanic activity during this period, indicating that the PETM event was associated with regional volcanic activity.</div></div>","PeriodicalId":400,"journal":{"name":"Organic Geochemistry","volume":"200 ","pages":"Article 104899"},"PeriodicalIF":2.6,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143176266","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}
Pub Date : 2025-01-27DOI: 10.1016/j.orggeochem.2025.104945
Jenan Kharbush , Raisha Rahman , Ann Pearson , Alice Zhou
Compound-specific isotope analysis of amino acids (AAs) can reveal the sources and transformations of nitrogen in ecological and environmental studies. However, there is limited information on microbial patterns of 15N distributions in AAs and the intracellular biochemical processes that determine these patterns. This leads to gaps in understanding the underlying mechanisms that determine the 15N content of key N-containing biomarkers. Here we measured δ15N values of both free and protein-bound amino acids in metabolically flexible Rhodopseudomonas palustris grown photomixotrophically under anoxic conditions. Patterns of 15N distribution in protein-bound amino acids of R. palustris resemble aerobic phototrophs, implying these microbial groups may be indistinguishable in environmental samples. Intriguingly, free amino acids consistently are ca. 5 ‰ enriched in 15N relative to protein-bound amino acids; this pattern may provide a new window to understanding intracellular fractionating processes during metabolite recycling and protein synthesis.
{"title":"Nitrogen stable isotope patterns in free and protein-bound amino acids of the anoxygenic phototroph, Rhodopseudomonas palustris","authors":"Jenan Kharbush , Raisha Rahman , Ann Pearson , Alice Zhou","doi":"10.1016/j.orggeochem.2025.104945","DOIUrl":"10.1016/j.orggeochem.2025.104945","url":null,"abstract":"<div><div>Compound-specific isotope analysis of amino acids (AAs) can reveal the sources and transformations of nitrogen in ecological and environmental studies. However, there is limited information on microbial patterns of <sup>15</sup>N distributions in AAs and the intracellular biochemical processes that determine these patterns. This leads to gaps in understanding the underlying mechanisms that determine the <sup>15</sup>N content of key N-containing biomarkers. Here we measured δ<sup>15</sup>N values of both free and protein-bound amino acids in metabolically flexible <em>Rhodopseudomonas palustris</em> grown photomixotrophically under anoxic conditions. Patterns of <sup>15</sup>N distribution in protein-bound amino acids of <em>R. palustris</em> resemble aerobic phototrophs, implying these microbial groups may be indistinguishable in environmental samples. Intriguingly, free amino acids consistently are <em>ca.</em> 5 ‰ enriched in <sup>15</sup>N relative to protein-bound amino acids; this pattern may provide a new window to understanding intracellular fractionating processes during metabolite recycling and protein synthesis.</div></div>","PeriodicalId":400,"journal":{"name":"Organic Geochemistry","volume":"201 ","pages":"Article 104945"},"PeriodicalIF":2.6,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145072","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}
Pub Date : 2025-01-22DOI: 10.1016/j.orggeochem.2025.104943
Chun Zhu , Clifford C. Walters , J. Alex Zumberge , Marlene Madincea
Gymnosperm and angiosperm are sister clades of seed-plants thriving on land since the Carboniferous and Cretaceous, respectively. Both biosynthesize specific terpenoids whose diagenetic hydrocarbon skeletons are preserved in geological samples as molecular fossils of seed-plants. Although the radiation of seed-plants has been well established, the temporal distributions of their biomarkers in geological samples remain poorly characterized. We defined angiosperm and gymnosperm ratios to quantify the relative abundances of seed-plant terpanes and examined the relationship between these ratios and geological age via well-studied, world-wide, petroleum samples deposited in various environments. Although angiosperm ratios show broad ranges in the Cretaceous – Tertiary samples, the Epoch-maxima increase from Early Cretaceous to Paleocene, and from Paleocene to Eocene-Miocene. Gymnosperm ratios remain low pre-Jurassic; however, the Period-maxima significantly increase from pre-Jurassic to Jurassic, and further increase from Jurassic to Cretaceous-Tertiary. These patterns are consistent with seed-plant evolution. We propose three age indicators: 1) O/(O + 29Ts) − an oleanane-based angiosperm ratio to distinguish age of Early Cretaceous or younger vs. Paleocene or younger vs. Eocene or younger; 2) Retene/(Retene + DBT) − a retene-based gymnosperm ratio to differentiate Jurassic or younger vs. Cretaceous or younger; and 3) under marine influence (DBT/P > 0.05), enrichment of retene [Retene/(Retene + DBT) > 0.3] and absence of oleanane [O/(O + 29Ts) < 0.04] indicative of Jurassic – Early Cretaceous. The three new age indicators improve age resolution of published age biomarkers from Era to Period level for oil age differentiation, a critical factor in de-risking petroleum systems.
{"title":"The temporal distributions of seed-plant terpanes in petroleum samples: Implications as oil age-diagnostic biomarkers for crude oils","authors":"Chun Zhu , Clifford C. Walters , J. Alex Zumberge , Marlene Madincea","doi":"10.1016/j.orggeochem.2025.104943","DOIUrl":"10.1016/j.orggeochem.2025.104943","url":null,"abstract":"<div><div>Gymnosperm and angiosperm are sister clades of seed-plants thriving on land since the Carboniferous and Cretaceous, respectively. Both biosynthesize specific terpenoids whose diagenetic hydrocarbon skeletons are preserved in geological samples as molecular fossils of seed-plants. Although the radiation of seed-plants has been well established, the temporal distributions of their biomarkers in geological samples remain poorly characterized. We defined angiosperm and gymnosperm ratios to quantify the relative abundances of seed-plant terpanes and examined the relationship between these ratios and geological age via well-studied, world-wide, petroleum samples deposited in various environments. Although angiosperm ratios show broad ranges in the Cretaceous – Tertiary samples, the Epoch-maxima increase from Early Cretaceous to Paleocene, and from Paleocene to Eocene-Miocene. Gymnosperm ratios remain low pre-Jurassic; however, the Period-maxima significantly increase from pre-Jurassic to Jurassic, and further increase from Jurassic to Cretaceous-Tertiary. These patterns are consistent with seed-plant evolution. We propose three age indicators: 1) O/(O + 29Ts) − an oleanane-based angiosperm ratio to distinguish age of Early Cretaceous or younger vs. Paleocene or younger vs. Eocene or younger; 2) Retene/(Retene + DBT) − a retene-based gymnosperm ratio to differentiate Jurassic or younger vs. Cretaceous or younger; and 3) under marine influence (DBT/P > 0.05), enrichment of retene [Retene/(Retene + DBT) > 0.3] and absence of oleanane [O/(O + 29Ts) < 0.04] indicative of Jurassic – Early Cretaceous. The three new age indicators improve age resolution of published age biomarkers from Era to Period level for oil age differentiation, a critical factor in de-risking petroleum systems.</div></div>","PeriodicalId":400,"journal":{"name":"Organic Geochemistry","volume":"201 ","pages":"Article 104943"},"PeriodicalIF":2.6,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145153","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}
Pub Date : 2025-01-17DOI: 10.1016/j.orggeochem.2025.104933
Dorota Staneczek, Leszek Marynowski
This study employs an integrated approach to investigate the thermal maturity of sedimentary rocks within the Central Carpathian Paleogene Basin (CCPB) by combining biomarker and non-biomarker parameters. The research primarily applies biomarker ratios based on the distribution of aliphatic and aromatic hydrocarbons and compares them with other paleotemperature indicators such as Rock-Eval pyrolysis. The results reveal a notable thermal gradient across the CCPB. The highest maturity levels are recorded in the Spiš Basin with calculated vitrinite reflectance values exceeding 2.0 %, and the least mature in the Orava Basin and Šariš Upland. The latter two contain unsaturated compounds, indicating immature organic matter. The variations in the paleotemperature pattern emerge from the changing thickness of overlying rocks in these areas. The findings suggest that the calculated vitrinite reflectance derived from the methylphenanthrene index (MPI1) is the most appropriate method for characterizing the broadest maturity range. When comparing the results of the illite/smectite-derived paleotemperatures with biomarker-derived ones, there is a good agreement in the results of the rocks with a higher degree of maturity. In contrast, at lower maturities, the illite/smectite-derived paleotemperatures appear to be overestimated. This study highlights the limitations of using a single maturity indicator and argues for a comprehensive approach combining different parameters to accurately reconstruct paleotemperatures. These results advance our understanding of the geological evolution of the CCPB and provide valuable information for future hydrocarbon exploration in the region. The CCPB is an excellent testing ground for comparing different maturity parameters.
{"title":"Application of biomarker and non-biomarker parameters to assess maturity using the Central Carpathian Paleogene Basin as a case study","authors":"Dorota Staneczek, Leszek Marynowski","doi":"10.1016/j.orggeochem.2025.104933","DOIUrl":"10.1016/j.orggeochem.2025.104933","url":null,"abstract":"<div><div>This study employs an integrated approach to investigate the thermal maturity of sedimentary rocks within the Central Carpathian Paleogene Basin (CCPB) by combining biomarker and non-biomarker parameters. The research primarily applies biomarker ratios based on the distribution of aliphatic and aromatic hydrocarbons and compares them with other paleotemperature indicators such as Rock-Eval pyrolysis. The results reveal a notable thermal gradient across the CCPB. The highest maturity levels are recorded in the Spiš Basin with calculated vitrinite reflectance values exceeding 2.0 %, and the least mature in the Orava Basin and Šariš Upland. The latter two contain unsaturated compounds, indicating immature organic matter. The variations in the paleotemperature pattern emerge from the changing thickness of overlying rocks in these areas. The findings suggest that the calculated vitrinite reflectance derived from the methylphenanthrene index (MPI1) is the most appropriate method for characterizing the broadest maturity range. When comparing the results of the illite/smectite-derived paleotemperatures with biomarker-derived ones, there is a good agreement in the results of the rocks with a higher degree of maturity. In contrast, at lower maturities, the illite/smectite-derived paleotemperatures appear to be overestimated. This study highlights the limitations of using a single maturity indicator and argues for a comprehensive approach combining different parameters to accurately reconstruct paleotemperatures. These results advance our understanding of the geological evolution of the CCPB and provide valuable information for future hydrocarbon exploration in the region. The CCPB is an excellent testing ground for comparing different maturity parameters.</div></div>","PeriodicalId":400,"journal":{"name":"Organic Geochemistry","volume":"201 ","pages":"Article 104933"},"PeriodicalIF":2.6,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143145152","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}
Pub Date : 2025-01-16DOI: 10.1016/j.orggeochem.2025.104934
Bowen Xiao , Dënë Cheecham-Uhrich , David C. Eickmeyer , Linda E. Kimpe , Vilmantas Prėskienis , E. Henriikka Kivilä , Meiling Man , Myrna J. Simpson , Irena Creed , Milla Rautio , Jules M. Blais
We conducted an analysis of n-alkanes, lignin-derived phenols, and other sediment markers from 19 lakes across four ecoregions in Saskatchewan, Canada, spanning from Prairie Grassland to Boreal Upland. Our goal was to establish whether these biomarkers relate to different ecoregions and land cover types (herbaceous plants vs trees) in the catchments of these lakes. Our findings revealed a significant inverse correlation between the proportion of herbaceous plants to trees in a lake’s catchment and the proportion of aquatic n-alkanes Paq (C23 + C25)/(C23 + C25 + C29 + C31) indicating that aquatic plants contributed proportionally more to sedimentary n-alkanes when the catchments were mostly in Boreal forest. We also observed significant positive correlations between the proportion of herbaceous plants to trees in a lake’s catchment and the n-alkane composition ratios C31/(C27 + C31) and C31/(C27 + C29 + C31), reflecting higher relative inputs of C31 from herbaceous vegetation. These findings suggest that these ratios could potentially be utilized to infer historical land cover composition based on dated sediment records. Moreover, variations in the C31/(C27 + C31) alkane ratio were observed among ecoregions, particularly between Prairie Grassland and the forest-dominated areas. We found no correlations between chlorophyll-a concentrations in lake water and the above-mentioned n-alkane ratios in sediment, suggesting that these ratios primarily reflect land cover composition rather than autochthonous production in the lakes. Additionally, the C/N ratio and δ13C were not effective in distinguishing ecoregions or land cover composition, likely due to influences from algal production and perhaps agricultural activities in surrounding farmland. In contrast, lignin-derived phenols in sediments showed relatively little association with their respective ecoregions and appeared to be influenced by decomposition as evidenced by high ratios of carboxylic acids relative to aldehydes (Ad/Al). Overall, our research highlights the potential of n-alkanes as biomarkers for tracking distinct land cover types due to their strong associations with the proportion of grasses and trees.
{"title":"Long chain n-alkanes in lake sediment track differences in adjacent land vegetation.","authors":"Bowen Xiao , Dënë Cheecham-Uhrich , David C. Eickmeyer , Linda E. Kimpe , Vilmantas Prėskienis , E. Henriikka Kivilä , Meiling Man , Myrna J. Simpson , Irena Creed , Milla Rautio , Jules M. Blais","doi":"10.1016/j.orggeochem.2025.104934","DOIUrl":"10.1016/j.orggeochem.2025.104934","url":null,"abstract":"<div><div>We conducted an analysis of <em>n</em>-alkanes, lignin-derived phenols, and other sediment markers from 19 lakes across four ecoregions in Saskatchewan, Canada, spanning from Prairie Grassland to Boreal Upland. Our goal was to establish whether these biomarkers relate to different ecoregions and land cover types (herbaceous plants vs trees) in the catchments of these lakes. Our findings revealed a significant inverse correlation between the proportion of herbaceous plants to trees in a lake’s catchment and the proportion of aquatic <em>n</em>-alkanes <em>P</em><sub>aq</sub> (C<sub>23</sub> + C<sub>25</sub>)/(C<sub>23</sub> + C<sub>25</sub> + C<sub>29</sub> + C<sub>31</sub>) indicating that aquatic plants contributed proportionally more to sedimentary <em>n</em>-alkanes when the catchments were mostly in Boreal forest. We also observed significant positive correlations between the proportion of herbaceous plants to trees in a lake’s catchment and the <em>n</em>-alkane composition ratios C<sub>31</sub>/(C<sub>27</sub> + C<sub>31</sub>) and C<sub>31</sub>/(C<sub>27</sub> + C<sub>29</sub> + C<sub>31</sub>), reflecting higher relative inputs of C<sub>31</sub> from herbaceous vegetation. These findings suggest that these ratios could potentially be utilized to infer historical land cover composition based on dated sediment records. Moreover, variations in the C<sub>31</sub>/(C<sub>27</sub> + C<sub>31</sub>) alkane ratio were observed among ecoregions, particularly between Prairie Grassland and the forest-dominated areas. We found no correlations between chlorophyll-<em>a</em> concentrations in lake water and the above-mentioned <em>n</em>-alkane ratios in sediment, suggesting that these ratios primarily reflect land cover composition rather than autochthonous production in the lakes. Additionally, the C/N ratio and δ<sup>13</sup>C were not effective in distinguishing ecoregions or land cover composition, likely due to influences from algal production and perhaps agricultural activities in surrounding farmland. In contrast, lignin-derived phenols in sediments showed relatively little association with their respective ecoregions and appeared to be influenced by decomposition as evidenced by high ratios of carboxylic acids relative to aldehydes (Ad/Al). Overall, our research highlights the potential of <em>n</em>-alkanes as biomarkers for tracking distinct land cover types due to their strong associations with the proportion of grasses and trees.</div></div>","PeriodicalId":400,"journal":{"name":"Organic Geochemistry","volume":"202 ","pages":"Article 104934"},"PeriodicalIF":2.6,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143395821","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}
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