Geochimica et Cosmochimica Acta最新文献

{"title":"Structure-informed prediction of organic matter thermodynamics from quantum chemistry and machine learning","authors":"Thomas P. Sibille,&nbsp;Klaus-Holger Knorr,&nbsp;Oliver J. Lechtenfeld,&nbsp;Maximilian P. Lau","doi":"10.1016/j.gca.2026.08.034","DOIUrl":"10.1016/j.gca.2026.08.034","url":null,"abstract":"<div><div>Thermodynamic constraints shape the degradation and persistence of dissolved organic matter (DOM) in aquatic environments. Predicting the Gibbs energy of the oxidation half reaction per mole of carbon (ΔG^°₍<em>_Cox</em>₎) is therefore central to assessing the thermodynamic potential of organic matter degradation. A widely used approach is the linear relationship between nominal oxidation state of carbon (NOSC) and ΔG^°₍<em>_Cox</em>₎, introduced by LaRowe and Van Cappellen, which provides a convenient and versatile single-proxy estimate. However, NOSC is a stoichiometric descriptor and assigns identical ΔG^°₍<em>_Cox</em>₎ values to formulae that reflect structures differing by more than 90 kJ molC^-1. This underlying diversity of structures can be isomeric, but can also reflect variation in molecular size, heteroatom composition, hydrogen abundance, and level of unsaturation. Here we present a structure-informed Random Forest model for ΔG^°₍<em>_Cox</em>₎ trained on a curated set of over 3,500 quantum-chemically calculated DOM-relevant molecules spanning diverse elemental compositions and structures. The model was trained using formula-derived descriptors, including elemental ratios, molecular mass (M_r), double bond equivalence (DBE), heteroatom content, NOSC and others. Predictions are made at the molecular level and represent an average across potential isomers of a formula. It relies on ΔG^°₍<em>_Cox</em>₎ data derived with the Becke three-parameter Lee-Yang-Parr density functional (B3LYP) and captures thermodynamic variability that the NOSC-based linear relationship systematically misses. As proof of concept, the model was applied to ultra-high resolution mass spectrometry (UHR-MS) data for four benchmark DOM reference materials, yielding ΔG^°₍<em>_Cox</em>₎ distributions that are broader and multimodal compared to the NOSC-based estimates. These results demonstrate that machine learning models grounded in quantum chemical data provide a more differentiated thermodynamic representation of DOM formula space and support improved prediction of organic matter oxidation potential.</div></div>","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"431 ","pages":"Pages 247-259"},"PeriodicalIF":5.2,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148885179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of pressure and temperature on the fluid/melt partitioning of porphyry ore metals","authors":"Ivano Gennaro,Alexandra Tsay,Zoltán Zajacz","doi":"10.1016/j.gca.2026.09.039","DOIUrl":"https://doi.org/10.1016/j.gca.2026.09.039","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"16 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149091082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recycling of terrestrial mercury in modern subduction zones: constraints from Hg-Sr-Nd-B isotope systematics","authors":"Dian-Bing Wang,Ping-Ping Liu,Runsheng Yin","doi":"10.1016/j.gca.2026.09.040","DOIUrl":"https://doi.org/10.1016/j.gca.2026.09.040","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"17 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149091084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solubility of tholins in hexane, acetonitrile, and acrylonitrile: Implications for Titan’s lakes","authors":"Yohann Layssac,Troy L. Williams,Rohana Liyanage,Jackson O. Lay,Vincent F. Chevrier","doi":"10.1016/j.gca.2026.09.041","DOIUrl":"https://doi.org/10.1016/j.gca.2026.09.041","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"1 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149091080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Rapid changes to permeable, continental shelf sediment pore water geochemistry in response to olivine addition as a marine carbon dioxide removal technique","authors":"Matthew Quinan,Aaron Celestian,Nick Rollins,Zvi Steiner,William Berelson","doi":"10.1016/j.gca.2026.10.017","DOIUrl":"https://doi.org/10.1016/j.gca.2026.10.017","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"17 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multi-site Li diffusion and coupling to Cr, REE, and P in garnet: Experimental data and implications for interpreting diffusion profiles in natural systems","authors":"E.M. Bloch,A. Devoir,O. Müntener,R. Hervig,J.J. Barnes,M.J. Kohn","doi":"10.1016/j.gca.2026.10.010","DOIUrl":"https://doi.org/10.1016/j.gca.2026.10.010","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"12 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149151024","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Archaeal lipid hydrogen isotope fractionation reveals carbon and energy metabolism in seep ecosystems","authors":"Jiachen Fan,Hongxiang Guan,Zeji Wang,Xiaoyan Xu,Xiaoming Miao,Qi Li,Huaichun Wu,Sanzhong Li,Nengyou Wu","doi":"10.1016/j.gca.2026.10.006","DOIUrl":"https://doi.org/10.1016/j.gca.2026.10.006","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"9 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149091086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Behavior of major to trace elements, volatiles, and metals during basaltic arc magma differentiation: a slow-cooling experimental study at 1.5, 1.0, 0.7, and 0.4 GPa","authors":"Jia Chang,Andreas Audétat","doi":"10.1016/j.gca.2026.10.004","DOIUrl":"https://doi.org/10.1016/j.gca.2026.10.004","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"483 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149091088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diagenetic pathways and preservation of bulk and amino acid δ15N in bivalve shell organic matter across the Holocene to the Pliocene","authors":"Qian Huang,Kirsty E.H. Penkman,Ellie Nelson,Daniel Vigelius,Thomas Tütken,Lukas Fröhlich,Bernd R. Schöne","doi":"10.1016/j.gca.2026.09.036","DOIUrl":"https://doi.org/10.1016/j.gca.2026.09.036","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"199 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149091089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Apatite in chang’e-6 mare basalts reveals a heterogeneous distribution of chlorine in the moon","authors":"Sen Hu,Mengfan Qiu,Linxi Li,Hejiu Hui,Jialong Hao,Huicun He,Yubing Gao,Liang Gao,Zhan Zhou,Mahesh Anand,Wei Yang,Yangting Lin,Xian-Hua Li,Fu-Yuan Wu","doi":"10.1016/j.gca.2026.10.007","DOIUrl":"https://doi.org/10.1016/j.gca.2026.10.007","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"12 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149151023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}