Pub Date : 2026-03-14DOI: 10.1016/j.gca.2026.03.019
Xuechao Wu, Qingzhen Hao, Slobodan B. Marković, Xinbo Gao, Long Han, Yu Fu, Yang Song, Zhipeng Wu, Shouye Yang, Zhengtang Guo
{"title":"Grain-size-specific Sr–Nd isotopic evidence for the dominant role of fluvial sediments in Danube loess formation","authors":"Xuechao Wu, Qingzhen Hao, Slobodan B. Marković, Xinbo Gao, Long Han, Yu Fu, Yang Song, Zhipeng Wu, Shouye Yang, Zhengtang Guo","doi":"10.1016/j.gca.2026.03.019","DOIUrl":"https://doi.org/10.1016/j.gca.2026.03.019","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"100 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147447932","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}
Pub Date : 2026-03-14DOI: 10.1016/j.gca.2026.03.014
Daniel R. Dunlap, Julia A. Cartwright, Piers Koefoed, Evgenii Krestianinov, Stephen J. Romaniello, Carl Agee, Yuri Amelin, Meenakshi Wadhwa
The chronology of ungrouped achondrites provides key insights into the timeline of igneous activity in the early Solar System. Two ungrouped achondrites – Northwest Africa (NWA) 11119 (andesite-dacite) and NWA 8486 and its pair NWA 7325 (olivine gabbro) – are the focus of this study, where their chronologies are investigated using multiple high-resolution techniques. Here we report the lead-lead (207Pb-206Pb) and manganese-chromium (53Mn-53Cr) systematics of NWA 11119, as well as the 207Pb-206Pb systematics of NWA 8486 alongside aluminum-magnesium (26Al-26Mg) systematics for NWA 7325. The U-corrected 207Pb-206Pb ages of NWA 11119 and the combined ages of NWA 7325/8486 are 4566.4 ± 0.8 Ma and 4563.8 ± 1.9 Ma, respectively. Additionally, we report the 53Mn-53Cr age of NWA 11119 to be 4564.4 ± 2.5 Ma and the 26Al-26Mg age of NWA 7325/8486 to be 4563.1 ± 0.3 Ma.
{"title":"Chronology of ungrouped achondrites Northwest Africa 11119 and 7325/8486: implications for early evolution of a heterogeneous crust on a differentiated planetesimal","authors":"Daniel R. Dunlap, Julia A. Cartwright, Piers Koefoed, Evgenii Krestianinov, Stephen J. Romaniello, Carl Agee, Yuri Amelin, Meenakshi Wadhwa","doi":"10.1016/j.gca.2026.03.014","DOIUrl":"https://doi.org/10.1016/j.gca.2026.03.014","url":null,"abstract":"The chronology of ungrouped achondrites provides key insights into the timeline of igneous activity in the early Solar System. Two ungrouped achondrites – Northwest Africa (NWA) 11119 (andesite-dacite) and NWA 8486 and its pair NWA 7325 (olivine gabbro) – are the focus of this study, where their chronologies are investigated using multiple high-resolution techniques. Here we report the lead-lead (<ce:sup loc=\"post\">207</ce:sup>Pb-<ce:sup loc=\"post\">206</ce:sup>Pb) and manganese-chromium (<ce:sup loc=\"post\">53</ce:sup>Mn-<ce:sup loc=\"post\">53</ce:sup>Cr) systematics of NWA 11119, as well as the <ce:sup loc=\"post\">207</ce:sup>Pb-<ce:sup loc=\"post\">206</ce:sup>Pb systematics of NWA 8486 alongside aluminum-magnesium (<ce:sup loc=\"post\">26</ce:sup>Al-<ce:sup loc=\"post\">26</ce:sup>Mg) systematics for NWA 7325. The U-corrected <ce:sup loc=\"post\">207</ce:sup>Pb-<ce:sup loc=\"post\">206</ce:sup>Pb ages of NWA 11119 and the combined ages of NWA 7325/8486 are 4566.4 ± 0.8 Ma and 4563.8 ± 1.9 Ma, respectively. Additionally, we report the <ce:sup loc=\"post\">53</ce:sup>Mn-<ce:sup loc=\"post\">53</ce:sup>Cr age of NWA 11119 to be 4564.4 ± 2.5 Ma and the <ce:sup loc=\"post\">26</ce:sup>Al-<ce:sup loc=\"post\">26</ce:sup>Mg age of NWA 7325/8486 to be 4563.1 ± 0.3 Ma.","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"11 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147465118","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}
Pub Date : 2026-03-14DOI: 10.1016/j.gca.2026.03.023
Zhiyu Zeng, Yilun Xu, Weiqi Yao
The Oceanic Anoxic Event 2 (OAE2) represents the episode of large-scale ocean oxygen loss under extreme warmth in the late Cretaceous. The initiation of the OAE2 has been attributed to massive volcanic carbon emissions related to the emplacement of Large Igneous Provinces (LIPs), accompanied by significant perturbations in biogeochemical cycles of carbon, oxygen, and sulfur. Given the lower sulfate concentration in the Cretaceous ocean than it is today, its residence time was shorter under comparable fluxes, increasing the likelihood of spatial heterogeneity in the marine sulfur cycle. Since most existing data of seawater sulfate S-isotope ratio (δ34S) for the OAE2 are reported from localities distant from LIPs, our understanding of the effects of volcanism on regional sulfur cycling and climate warming remains poorly constrained. In this study, we present marine barite δ34S and TEX86-derived sea-surface temperature (SST) records across the OAE2 from the Mentelle Basin, which was proximal to the active Kerguelen LIP (KLIP) in Southern high latitudes. Our result shows a basin-scale ∼5‰ decrease in seawater sulfate δ34S during the OAE2, followed by a recovery to the higher-than-pre-excursion value in the post-OAE2. The simple box model attributes the δ34S decline to a volcanic pulse of 6.96 × 1012 mol isotopically light sulfur released into the ocean within 50 thousand years, which is approximately threefold of the background flux. The subsequent δ34S overshoot requires a coeval increase in pyrite burial flux by 10%, indicating a modest expansion of anoxia in the Mentelle Basin. Meanwhile, the TEX86-derived SST documents prolonged warmth persisting into the post-OAE2, providing an independent constraint on thermal forcing during the recovery phase. Sustained elevated SST in the high-latitude Southern Hemisphere would not only have promoted basin-scale deoxygenation and pyrite burial beyond the initial volcanic perturbation, but also reduced the meridional SST gradient and efficiency of poleward heat redistribution, thereby acting as positive feedback that helped sustain global warming. These findings reveal the response of basin-scale sulfur cycling and persistent warmth to volcanic activities in the high-latitude ocean across the OAE2.
{"title":"Basin-scale sulfur cycling driven by volcanism in Southern high latitudes during the Oceanic Anoxic Event 2","authors":"Zhiyu Zeng, Yilun Xu, Weiqi Yao","doi":"10.1016/j.gca.2026.03.023","DOIUrl":"https://doi.org/10.1016/j.gca.2026.03.023","url":null,"abstract":"The Oceanic Anoxic Event 2 (OAE2) represents the episode of large-scale ocean oxygen loss under extreme warmth in the late Cretaceous. The initiation of the OAE2 has been attributed to massive volcanic carbon emissions related to the emplacement of Large Igneous Provinces (LIPs), accompanied by significant perturbations in biogeochemical cycles of carbon, oxygen, and sulfur. Given the lower sulfate concentration in the Cretaceous ocean than it is today, its residence time was shorter under comparable fluxes, increasing the likelihood of spatial heterogeneity in the marine sulfur cycle. Since most existing data of seawater sulfate S-isotope ratio (δ<ce:sup loc=\"post\">34</ce:sup>S) for the OAE2 are reported from localities distant from LIPs, our understanding of the effects of volcanism on regional sulfur cycling and climate warming remains poorly constrained. In this study, we present marine barite δ<ce:sup loc=\"post\">34</ce:sup>S and TEX<ce:inf loc=\"post\">86</ce:inf>-derived sea-surface temperature (SST) records across the OAE2 from the Mentelle Basin, which was proximal to the active Kerguelen LIP (KLIP) in Southern high latitudes. Our result shows a basin-scale ∼5‰ decrease in seawater sulfate δ<ce:sup loc=\"post\">34</ce:sup>S during the OAE2, followed by a recovery to the higher-than-pre-excursion value in the post-OAE2. The simple box model attributes the δ<ce:sup loc=\"post\">34</ce:sup>S decline to a volcanic pulse of 6.96 × 10<ce:sup loc=\"post\">12</ce:sup> mol isotopically light sulfur released into the ocean within 50 thousand years, which is approximately threefold of the background flux. The subsequent δ<ce:sup loc=\"post\">34</ce:sup>S overshoot requires a coeval increase in pyrite burial flux by 10%, indicating a modest expansion of anoxia in the Mentelle Basin. Meanwhile, the TEX<ce:inf loc=\"post\">86</ce:inf>-derived SST documents prolonged warmth persisting into the post-OAE2, providing an independent constraint on thermal forcing during the recovery phase. Sustained elevated SST in the high-latitude Southern Hemisphere would not only have promoted basin-scale deoxygenation and pyrite burial beyond the initial volcanic perturbation, but also reduced the meridional SST gradient and efficiency of poleward heat redistribution, thereby acting as positive feedback that helped sustain global warming. These findings reveal the response of basin-scale sulfur cycling and persistent warmth to volcanic activities in the high-latitude ocean across the OAE2.","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"11 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147465117","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}
Pub Date : 2026-03-13DOI: 10.1016/j.gca.2026.03.018
Yadan Hu, Fei Zhang, Chen Chen, Ying Xie, Li Deng, Xiangying Li, Xiaolong Zhang, Guang Bao, Jinzhao Liu, Zhangdong Jin
{"title":"Lithium isotopes as a new indicator for change in hydrology","authors":"Yadan Hu, Fei Zhang, Chen Chen, Ying Xie, Li Deng, Xiangying Li, Xiaolong Zhang, Guang Bao, Jinzhao Liu, Zhangdong Jin","doi":"10.1016/j.gca.2026.03.018","DOIUrl":"https://doi.org/10.1016/j.gca.2026.03.018","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"127 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147447933","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}
Pub Date : 2026-03-13DOI: 10.1016/j.gca.2026.03.016
Caineng Zou, Yanjie Gong, Thomas J. Algeo, Jiubin Chen, Qingong Zhuo, Ruoyu Sun, Zhengfu Zhao, Weiyan Chen
{"title":"Late Triassic hyperwarming and its link to nitrogen-cycle climate feedbacks","authors":"Caineng Zou, Yanjie Gong, Thomas J. Algeo, Jiubin Chen, Qingong Zhuo, Ruoyu Sun, Zhengfu Zhao, Weiyan Chen","doi":"10.1016/j.gca.2026.03.016","DOIUrl":"https://doi.org/10.1016/j.gca.2026.03.016","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"51 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147447934","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}
Pub Date : 2026-03-13DOI: 10.1016/j.gca.2026.03.020
Bianka Babrián, Queenie H.S. Chan, Jens Najorka, James Malley, Lee F. White, Martin D. Suttle
{"title":"Permeability as the first-order control on the rate of aqueous alteration in carbonaceous chondrites","authors":"Bianka Babrián, Queenie H.S. Chan, Jens Najorka, James Malley, Lee F. White, Martin D. Suttle","doi":"10.1016/j.gca.2026.03.020","DOIUrl":"https://doi.org/10.1016/j.gca.2026.03.020","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"16 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147447935","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}
Pub Date : 2026-03-12DOI: 10.1016/j.gca.2026.03.015
Zachary A. Torrano, Michelle K. Jordan, Lori N. Willhite, Richard W. Carlson
{"title":"The neodymium and samarium isotope compositions and cosmic ray exposure history of B-type asteroid (101955) Bennu","authors":"Zachary A. Torrano, Michelle K. Jordan, Lori N. Willhite, Richard W. Carlson","doi":"10.1016/j.gca.2026.03.015","DOIUrl":"https://doi.org/10.1016/j.gca.2026.03.015","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"23 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147447940","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":"Interaction between ilmenite-bearing cumulates and lunar mantle: implications for the origin of intermediate and high-titanium lunar basalts","authors":"Himela Moitra, Sujoy Ghosh, Tamalkanti Mukherjee, Saibal Gupta, Kuljeet Kaur Marhas","doi":"10.1016/j.gca.2026.03.008","DOIUrl":"https://doi.org/10.1016/j.gca.2026.03.008","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"93 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147447941","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}
Pub Date : 2026-03-11DOI: 10.1016/j.gca.2026.03.013
Xia Zhang, Chunming Lin, Robert W. Dalrymple, Cheng Cao, Daidu Fan, Guyue Tan, Xin Li
{"title":"Assessing the fidelity of clay-size lithium isotopes as chemical-weathering tracers in detrital sedimentary successions","authors":"Xia Zhang, Chunming Lin, Robert W. Dalrymple, Cheng Cao, Daidu Fan, Guyue Tan, Xin Li","doi":"10.1016/j.gca.2026.03.013","DOIUrl":"https://doi.org/10.1016/j.gca.2026.03.013","url":null,"abstract":"","PeriodicalId":327,"journal":{"name":"Geochimica et Cosmochimica Acta","volume":"53 1","pages":""},"PeriodicalIF":5.0,"publicationDate":"2026-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147447944","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}
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