Geochimica et Cosmochimica Acta最新文献

{"title":"Sulfur isotope fractionation during metal–silicate equilibration and implications for Earth’s mantle","authors":"Lucas Calvo,Jabrane Labidi,Anat Shahar,Edith Kubik,Julien Siebert","doi":"10.1016/j.gca.2026.09.042","DOIUrl":"https://doi.org/10.1016/j.gca.2026.09.042","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"26 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149091087","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":"Molybdenum redistribution and extreme isotope fractionation in a Barremian weathering profile revealed by scientific drilling","authors":"Qin Lin,Philip A.E. Pogge von Strandmann,Ming-Dao Sun,Peng-Li He,Le Zhang,Man Li,Yi-Jun Xiong,Jin-Long Ma,Jie Li,Yi-Gang Xu","doi":"10.1016/j.gca.2026.10.014","DOIUrl":"https://doi.org/10.1016/j.gca.2026.10.014","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"42 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209729","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":"Simultaneous formation of DNA and RNA nucleosides in shock-recovery experiments","authors":"Jiawen Zhao,Koichi Mimura","doi":"10.1016/j.gca.2026.10.020","DOIUrl":"https://doi.org/10.1016/j.gca.2026.10.020","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"14 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209731","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":"A new view of Xe and Ne in the Paleoarchean atmosphere from paired noble gas isotopic and trace element analyses of Barberton cherts","authors":"K.A. Woody,R. Parai,D.A. Fike,C. Jones,G. Avice,M.H. Barickman,J.B. Rodriguez,X.J. Zhang,A.H. Knoll","doi":"10.1016/j.gca.2026.10.015","DOIUrl":"https://doi.org/10.1016/j.gca.2026.10.015","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"18 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209726","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":"Lead isotopes trace interhemispheric transport of water masses and pollution to the tropical western North Atlantic Ocean","authors":"Hui Xu,Tina van de Flierdt,Arianna Olivelli,Yee-Lap Leung,Alex Griffiths,Katharina Kreissig,Barry J. Coles,Dominik J. Weiss,Rebekah E.T. Moore,Rob Middag,Mark Rehkämper","doi":"10.1016/j.gca.2026.10.008","DOIUrl":"https://doi.org/10.1016/j.gca.2026.10.008","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"478 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149209734","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":"Hydrothermal experiments reveal methanol, ammonia, and methylamines as tracers of pH and temperature with potential application to Enceladus, Europa, and other icy ocean worlds","authors":"Kirtland J. Robinson, Everett L. Shock, Sean P. Sylva, Jeffrey S. Seewald","doi":"10.1016/j.gca.2026.09.013","DOIUrl":"https://doi.org/10.1016/j.gca.2026.09.013","url":null,"abstract":"Icy ocean worlds in our solar system are prime targets in the search for extraterrestrial life. Enceladus and Europa are icy moons with evidence of global subsurface oceans in contact with rocky interiors, which may provide habitable environments for chemotrophic life. However, the interaction between water and rock and any changes in fluid chemistry are poorly constrained because the icy shells of these moons inhibit direct sampling of subsurface aqueous environments. Characterization of subseafloor processes may depend on chemical signatures in materials that are transported to accessible sampling locations near the surfaces of these icy ocean worlds. Here we present a theoretical framework where organic compounds likely to be present at icy ocean worlds can be utilized as tracers of geochemistry if they approach metastable equilibrium abundances, which we test with laboratory experiments. We use thermodynamic calculations of aqueous solutions to demonstrate that abundances of methanol, ammonia, and methylamines (compounds selected based on Enceladus’ plume data) should approach steady state ratios based on reversible substitution reactions that are systematically controlled by pH and temperature. We test these calculations by performing laboratory hydrothermal experiments ranging in temperature (175-325℃) and pH (∼3.5–7.0), demonstrating that chemical concentration measurements alone can be used in predictive models to accurately constrain the different conditions across experimental systems. As examples, with experiments conducted at 250℃, we demonstrate that the chemical tracers in a pH ∼ 3.5 solution predict a pH ≤ ∼5.0 and a temperature of ∼ 225-250℃, while the tracers in a solution at pH ∼ 7.0 predict a pH of ∼ 6.0–7.5 and a temperature of ∼ 200-275℃. Notably, all of our high-temperature experiments are cooled to room temperature prior to analysis, indicating that the hydrothermal signal (i.e., the ratio of chemical species) is preserved due to the slowing of reaction kinetics at lower temperatures, which may be analogous to hydrothermal fluids that vent into icy oceans. Similarly, we also performed a partial-cooling experiment that shows a tracer signal produced at 325℃ remains largely preserved for a year after the experiment was cooled to 175℃. We compare experimental results from gold reaction vessels to experiments previously conducted in glass vessels to assess the effects of experimental vessel type and find only minor differences in product distributions over time. Overall, our findings provide additional motivation to target small organic molecules for analysis on future missions to icy ocean worlds in order to constrain subsurface geochemical parameters critical to habitability","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"36 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148980600","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":"Time-resolved Mo isotopes track source evolution from recycled slab components to a coherent OIB-type mantle source","authors":"Dongjing Xu,Xiu-Zheng Zhang,Yue Qi,Jie Li,Bing Chen,Pei-Na Guo,Tao Du,Qiang Wang","doi":"10.1016/j.gca.2026.09.030","DOIUrl":"https://doi.org/10.1016/j.gca.2026.09.030","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"7 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149049768","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":"The importance of deep reactions between ascending komatiite and pre-existing protocratonic lithosphere for the chemistry of Archaean peridotites and greenstone belt volcanics: insights from reaction experiments","authors":"Rodrigo Freitas Rodrigues,Balz S. Kamber,Gregory M. Yaxley,Emma L. Tomlinson,Sandra Piazolo,Nathan R. Daczko","doi":"10.1016/j.gca.2026.09.009","DOIUrl":"https://doi.org/10.1016/j.gca.2026.09.009","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"59 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148933538","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":"Mercury isotopes in coral skeletons as proxies for marine Hg cycling: assessing fidelity and fractionation during biomineralization","authors":"Fei Cao,Yongquan Zhang,Ruoyu Sun,Larissa Schneider,Songjing Li,Rui Zhang,Pengfei Li,Wang Zheng,Jiubin Chen,Yi Liu","doi":"10.1016/j.gca.2026.09.025","DOIUrl":"https://doi.org/10.1016/j.gca.2026.09.025","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"166 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149049328","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":"Acceptance Speech for Treibs Award 2026 to Steven John Rowland by Professor emeritus Steven Rowland (University of Plymouth, England)","authors":"","doi":"10.1016/j.gca.2026.08.007","DOIUrl":"https://doi.org/10.1016/j.gca.2026.08.007","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"1 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-08-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148717646","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}