Marine Carbonates in the Mantle Source of Oceanic Basalts: Pb Isotopic Constraints

Abstract For almost fifty years, geochemists have been interpreting the clues from Pb isotopic ratios concerning mantle composition and evolution separately. The Pb isotopes of ocean island basalts (OIB) indicate that their mantle source is heterogeneous, most likely due to the presence of end-compo...

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Autores principales:	P. R. Castillo, C. MacIsaac, S. Perry, J. Veizer
Formato:	article
Lenguaje:	EN
Publicado:	Nature Portfolio 2018
Materias:	Oceanic Basalts Marine Carbonate Magma Generation Processes Carbonatite Melt Archaean Carbonates Medicine R Science Q
Acceso en línea:	https://doaj.org/article/72d1a946582a48388f37ba121587d48c
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spelling	oai:doaj.org-article:72d1a946582a48388f37ba121587d48c2021-12-02T15:08:01ZMarine Carbonates in the Mantle Source of Oceanic Basalts: Pb Isotopic Constraints10.1038/s41598-018-33178-42045-2322https://doaj.org/article/72d1a946582a48388f37ba121587d48c2018-10-01T00:00:00Zhttps://doi.org/10.1038/s41598-018-33178-4https://doaj.org/toc/2045-2322Abstract For almost fifty years, geochemists have been interpreting the clues from Pb isotopic ratios concerning mantle composition and evolution separately. The Pb isotopes of ocean island basalts (OIB) indicate that their mantle source is heterogeneous, most likely due to the presence of end-components derived from recycled crust and sediment. Some OIB have unusually high 206Pb/204Pb coming from one of the end-components with a long time-integrated high 238U/204Pb or μ (HIMU). Most OIB and many mid-ocean ridge basalts (MORB) also have high 206Pb/204Pb, indicating a HIMU-like source. Moreover, measured 232Th/238U (κ) for most MORB are lower than those deduced from their 208Pb/204Pb and 206Pb/204Pb. Such high μ and low κ features of oceanic basalts are inconsistent with the known geochemical behavior of U, Pb and Th and temporal evolution of the mantle; these have been respectively termed the 1st and 2nd Pb paradox. Here we show that subducted marine carbonates can be a source for HIMU and a solution to the Pb paradoxes. The results are consistent with the predictions of the marine carbonate recycling hypothesis that posits the Pb isotopes of oceanic basalts indicate a common origin and/or magma generation process.P. R. CastilloC. MacIsaacS. PerryJ. VeizerNature PortfolioarticleOceanic BasaltsMarine CarbonateMagma Generation ProcessesCarbonatite MeltArchaean CarbonatesMedicineRScienceQENScientific Reports, Vol 8, Iss 1, Pp 1-7 (2018)
institution	DOAJ
collection	DOAJ
language	EN
topic	Oceanic Basalts Marine Carbonate Magma Generation Processes Carbonatite Melt Archaean Carbonates Medicine R Science Q
spellingShingle	Oceanic Basalts Marine Carbonate Magma Generation Processes Carbonatite Melt Archaean Carbonates Medicine R Science Q P. R. Castillo C. MacIsaac S. Perry J. Veizer Marine Carbonates in the Mantle Source of Oceanic Basalts: Pb Isotopic Constraints
description	Abstract For almost fifty years, geochemists have been interpreting the clues from Pb isotopic ratios concerning mantle composition and evolution separately. The Pb isotopes of ocean island basalts (OIB) indicate that their mantle source is heterogeneous, most likely due to the presence of end-components derived from recycled crust and sediment. Some OIB have unusually high 206Pb/204Pb coming from one of the end-components with a long time-integrated high 238U/204Pb or μ (HIMU). Most OIB and many mid-ocean ridge basalts (MORB) also have high 206Pb/204Pb, indicating a HIMU-like source. Moreover, measured 232Th/238U (κ) for most MORB are lower than those deduced from their 208Pb/204Pb and 206Pb/204Pb. Such high μ and low κ features of oceanic basalts are inconsistent with the known geochemical behavior of U, Pb and Th and temporal evolution of the mantle; these have been respectively termed the 1st and 2nd Pb paradox. Here we show that subducted marine carbonates can be a source for HIMU and a solution to the Pb paradoxes. The results are consistent with the predictions of the marine carbonate recycling hypothesis that posits the Pb isotopes of oceanic basalts indicate a common origin and/or magma generation process.
format	article
author	P. R. Castillo C. MacIsaac S. Perry J. Veizer
author_facet	P. R. Castillo C. MacIsaac S. Perry J. Veizer
author_sort	P. R. Castillo
title	Marine Carbonates in the Mantle Source of Oceanic Basalts: Pb Isotopic Constraints
title_short	Marine Carbonates in the Mantle Source of Oceanic Basalts: Pb Isotopic Constraints
title_full	Marine Carbonates in the Mantle Source of Oceanic Basalts: Pb Isotopic Constraints
title_fullStr	Marine Carbonates in the Mantle Source of Oceanic Basalts: Pb Isotopic Constraints
title_full_unstemmed	Marine Carbonates in the Mantle Source of Oceanic Basalts: Pb Isotopic Constraints
title_sort	marine carbonates in the mantle source of oceanic basalts: pb isotopic constraints
publisher	Nature Portfolio
publishDate	2018
url	https://doaj.org/article/72d1a946582a48388f37ba121587d48c
work_keys_str_mv	AT prcastillo marinecarbonatesinthemantlesourceofoceanicbasaltspbisotopicconstraints AT cmacisaac marinecarbonatesinthemantlesourceofoceanicbasaltspbisotopicconstraints AT sperry marinecarbonatesinthemantlesourceofoceanicbasaltspbisotopicconstraints AT jveizer marinecarbonatesinthemantlesourceofoceanicbasaltspbisotopicconstraints
_version_	1718388322128101376

Marine Carbonates in the Mantle Source of Oceanic Basalts: Pb Isotopic Constraints

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