C. Tiraboschi, C. McCammon, A. Rohrbach, S. Klemme, J. Berndt, C. Sanchez‐Valle
{"title":"Preferential mobilisation of oxidised iron by slab-derived hydrous silicate melts","authors":"C. Tiraboschi, C. McCammon, A. Rohrbach, S. Klemme, J. Berndt, C. Sanchez‐Valle","doi":"10.7185/geochemlet.2304","DOIUrl":"https://doi.org/10.7185/geochemlet.2304","url":null,"abstract":"","PeriodicalId":12613,"journal":{"name":"Geochemical Perspectives Letters","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45220531","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}
N. Malaspina, G. Borghini, S. Zanchetta, L. Pellegrino, M. Corti, S. Tumiati
{"title":"Geochemical evolution of melt/peridotite interaction at high pressure in subduction zones","authors":"N. Malaspina, G. Borghini, S. Zanchetta, L. Pellegrino, M. Corti, S. Tumiati","doi":"10.7185/geochemlet.2305","DOIUrl":"https://doi.org/10.7185/geochemlet.2305","url":null,"abstract":"","PeriodicalId":12613,"journal":{"name":"Geochemical Perspectives Letters","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2023-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48646044","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":"K-Ca dating and Ca isotope composition of the oldest Solar System lava, Erg Chech 002","authors":"W. Dai, F. Moynier, L. Fang, J. Siebert","doi":"10.7185/geochemlet.2302","DOIUrl":"https://doi.org/10.7185/geochemlet.2302","url":null,"abstract":"","PeriodicalId":12613,"journal":{"name":"Geochemical Perspectives Letters","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44903771","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 dual role of methane seepage intensity on calcium isotopic fractionation","authors":"J. Wei, T. Wu, X. Miao","doi":"10.7185/geochemlet.2303","DOIUrl":"https://doi.org/10.7185/geochemlet.2303","url":null,"abstract":"","PeriodicalId":12613,"journal":{"name":"Geochemical Perspectives Letters","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44604274","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}
R. Bronner, K. Thompson, C. Dreher, E. Runge, E. Voggenreiter, J. Shuster, B. Wan, P. Joshi, S. Fischer, J. Duda, A. Kappler, M. Mansor
{"title":"Co-reduction of Fe(III) and S0 drives Fe-S biomineral formation and phosphate mobilisation","authors":"R. Bronner, K. Thompson, C. Dreher, E. Runge, E. Voggenreiter, J. Shuster, B. Wan, P. Joshi, S. Fischer, J. Duda, A. Kappler, M. Mansor","doi":"10.7185/geochemlet.2301","DOIUrl":"https://doi.org/10.7185/geochemlet.2301","url":null,"abstract":"","PeriodicalId":12613,"journal":{"name":"Geochemical Perspectives Letters","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41716761","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}
Zircon trace element and isotopic analysis for an increasing number of isotopic systems provide valuable insights into magma crystallisation, and evolution of the continental crust. Zirconium stable isotopes have been measured recently and shown to vary by several per mille on Earth. Both positive and negative shifts of δ94/90Zr have been found in zircons and melts, and equilibrium isotopic fractionations are found to be small. We here employ and further develop a zircon crystallisation programme with two moving boundaries targeting zircon crystallisation in the presence of other minerals. We reproduce positive, negative, and inverse δ94/90Zr, Zr/Hf, and other compatible trace element variations in zircon and surrounding melt that can be entirely explained by the boundary layer processes during kinetics of zircon crystallisation in a realistic set of geologic conditions. Progressively lower δ94/90Zr values in zircon develop during rapid crystallisation, lower melt water contents, crystallisation in the lower temperature range, and whilst co-crystallising with the Zr-poor phase. Given large (multi-per mille) kinetic Zr isotope fractionations discovered, zircon may serve as a monitor of magmatic crystallisation conditions, but is unlikely to serve as a diagnostic tool for the bigger set of petrological problems (e.g., evolution of the continental crust) without proper context.
{"title":"The rises and falls of zirconium isotopes during zircon crystallisation","authors":"I.N. Bindeman, O.E. Melnik","doi":"10.7185/geochemlet.2241","DOIUrl":"https://doi.org/10.7185/geochemlet.2241","url":null,"abstract":"Zircon trace element and isotopic analysis for an increasing number of isotopic systems provide valuable insights into magma crystallisation, and evolution of the continental crust. Zirconium stable isotopes have been measured recently and shown to vary by several per mille on Earth. Both positive and negative shifts of δ<sup>94/90</sup>Zr have been found in zircons and melts, and equilibrium isotopic fractionations are found to be small. We here employ and further develop a zircon crystallisation programme with two moving boundaries targeting zircon crystallisation in the presence of other minerals. We reproduce positive, negative, and inverse δ<sup>94/90</sup>Zr, Zr/Hf, and other compatible trace element variations in zircon and surrounding melt that can be entirely explained by the boundary layer processes during kinetics of zircon crystallisation in a realistic set of geologic conditions. Progressively lower δ<sup>94/90</sup>Zr values in zircon develop during rapid crystallisation, lower melt water contents, crystallisation in the lower temperature range, and whilst co-crystallising with the Zr-poor phase. Given large (multi-per mille) kinetic Zr isotope fractionations discovered, zircon may serve as a monitor of magmatic crystallisation conditions, but is unlikely to serve as a diagnostic tool for the bigger set of petrological problems (<em>e.g.</em>, evolution of the continental crust) without proper context.","PeriodicalId":12613,"journal":{"name":"Geochemical Perspectives Letters","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2022-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138531304","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}
Y. Yu, R. Xie, M. Gutjahr, G. Laukert, Z. Cao, E. Hathorne, C. Siebert, G. Patton, M. Frank
{"title":"High latitude controls on dissolved barium isotope distributions in the global ocean","authors":"Y. Yu, R. Xie, M. Gutjahr, G. Laukert, Z. Cao, E. Hathorne, C. Siebert, G. Patton, M. Frank","doi":"10.7185/geochemlet.2242","DOIUrl":"https://doi.org/10.7185/geochemlet.2242","url":null,"abstract":"","PeriodicalId":12613,"journal":{"name":"Geochemical Perspectives Letters","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42185216","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}
Phosphorus (P) concentrations in zircon have been used to discriminate their derivation from metaluminous versus strongly peraluminous granites (SPGs) based on the empirical observation of lower P concentrations in zircon from Phanerozoic metaluminous versus peraluminous granites. Higher P concentrations in zircon from Phanerozoic SPGs reflect enhanced apatite solubility in peraluminous melts and overall higher P concentrations in peraluminous granites. However, SPGs derived from partial melting of Precambrian sedimentary rocks have lower P concentrations compared to Phanerozoic metaluminous granites, reflecting lower P concentrations in Precambrian versus Phanerozoic sedimentary sources. We demonstrate that zircons from Precambrian SPGs also have lower P concentrations compared to Phanerozoic counterparts, likely reflecting lower P concentrations in their parental melts. Applying the P-in-zircon proxy to the detrital zircon record does not effectively discriminate between metaluminous and peraluminous sources and underestimates contributions from peraluminous granites. Although detrital zircons are an important early Earth archive, a uniformitarian perspective cannot always be applied when using trace element proxies developed on Phanerozoic samples.
{"title":"Secular variability in zircon phosphorus concentrations prevents simple petrogenetic classification","authors":"C.E. Bucholz, J. Liebmann, C.J. Spencer","doi":"10.7185/geochemlet.2240","DOIUrl":"https://doi.org/10.7185/geochemlet.2240","url":null,"abstract":"Phosphorus (P) concentrations in zircon have been used to discriminate their derivation from metaluminous <em>versus</em> strongly peraluminous granites (SPGs) based on the empirical observation of lower P concentrations in zircon from Phanerozoic metaluminous <em>versus</em> peraluminous granites. Higher P concentrations in zircon from Phanerozoic SPGs reflect enhanced apatite solubility in peraluminous melts and overall higher P concentrations in peraluminous granites. However, SPGs derived from partial melting of Precambrian sedimentary rocks have lower P concentrations compared to Phanerozoic metaluminous granites, reflecting lower P concentrations in Precambrian <em>versus</em> Phanerozoic sedimentary sources. We demonstrate that zircons from Precambrian SPGs also have lower P concentrations compared to Phanerozoic counterparts, likely reflecting lower P concentrations in their parental melts. Applying the P-in-zircon proxy to the detrital zircon record does not effectively discriminate between metaluminous and peraluminous sources and underestimates contributions from peraluminous granites. Although detrital zircons are an important early Earth archive, a uniformitarian perspective cannot always be applied when using trace element proxies developed on Phanerozoic samples.","PeriodicalId":12613,"journal":{"name":"Geochemical Perspectives Letters","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2022-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138531331","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}
Y. Sano, D. Pinti, T. Escobar-Nakajima, N. Takahata, M. Zhang, D. Goto, B. Marty
{"title":"Sun flare activity may solve unknown source of helium-3 in the atmosphere","authors":"Y. Sano, D. Pinti, T. Escobar-Nakajima, N. Takahata, M. Zhang, D. Goto, B. Marty","doi":"10.7185/geochemlet.2237","DOIUrl":"https://doi.org/10.7185/geochemlet.2237","url":null,"abstract":"","PeriodicalId":12613,"journal":{"name":"Geochemical Perspectives Letters","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2022-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47777154","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}
A. Dickson, M. Davies, Marie-Laure Bagard, A. Cohen
The closure of seaways that connected the Arctic Ocean to the global ocean during the early Paleogene led to severe hydrographic restriction. We present new osmium isotope datafrom organic-rich sediments deposited in the central ArcticOcean during the Early – Middle Eocene. The new data show that the long term isotopic composition of osmium in Arctic seawater began to diverge from that of the global ocean at ∼ 54 Ma, after the Eocene Thermal Maximum 2 hyperthermal event. This divergence was prob-ablycausedbythegradualclosure of seaways connectingtheArcticOceantothe global ocean. The Os data are used to calculate water exchange rates between the Arctic and surrounding oceans and to calculate Arctic Ocean salinity during the Early Eocene. The results show that the development of severe, long term Arctic Basin restriction after ∼ 54 Ma occurred as open ocean seawater input decreased below ∼ 0.01 Sv, resulting in a mean basin salinity between 8 – 16 PSU, depending on model assumptions.
{"title":"Quantifying seawater exchange rates in the Eocene Arctic Basin using osmium isotopes","authors":"A. Dickson, M. Davies, Marie-Laure Bagard, A. Cohen","doi":"10.7185/geochemlet.2239","DOIUrl":"https://doi.org/10.7185/geochemlet.2239","url":null,"abstract":"The closure of seaways that connected the Arctic Ocean to the global ocean during the early Paleogene led to severe hydrographic restriction. We present new osmium isotope datafrom organic-rich sediments deposited in the central ArcticOcean during the Early – Middle Eocene. The new data show that the long term isotopic composition of osmium in Arctic seawater began to diverge from that of the global ocean at ∼ 54 Ma, after the Eocene Thermal Maximum 2 hyperthermal event. This divergence was prob-ablycausedbythegradualclosure of seaways connectingtheArcticOceantothe global ocean. The Os data are used to calculate water exchange rates between the Arctic and surrounding oceans and to calculate Arctic Ocean salinity during the Early Eocene. The results show that the development of severe, long term Arctic Basin restriction after ∼ 54 Ma occurred as open ocean seawater input decreased below ∼ 0.01 Sv, resulting in a mean basin salinity between 8 – 16 PSU, depending on model assumptions.","PeriodicalId":12613,"journal":{"name":"Geochemical Perspectives Letters","volume":null,"pages":null},"PeriodicalIF":4.9,"publicationDate":"2022-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43927460","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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