Low-phosphorus concentrations and important ferric hydroxide scavenging in Archean seawater.

Autor:	Rego ES; Instituto de Geociências, Departamento de Mineralogia e Geotectônica, Universidade de São Paulo, Rua do Lago 562, Cidade Universitária, São Paulo, 05508-080, Brasil.; Géosciences Montpellier, Pl. Eugène Bataillon, Campus Triolet, Université de Montpellier, CNRS, Université des Antilles, 34095, Montpellier, France., Busigny V; Université Paris Cité, Institut de physique du globe de Paris, CNRS, 1 Rue Jussieu, 75238 Paris cedex 05, France., Lalonde SV; CNRS-UMR6538 Laboratoire Geo-Ocean, Institut Universitaire Européen de la Mer, Université de Bretagne Occidentale, Technopôle Brest-Iroise, Rue Dumont d'Urville, 29280, Plouzané, France., Rossignol C; Dipartimento di Scienze Chimiche e Geologiche, Università degli Studi di Cagliari, Str. interna Policlinico Universitario, 09042 Monserrato, Cagliari, Italia., Babinski M; Instituto de Geociências, Departamento de Mineralogia e Geotectônica, Universidade de São Paulo, Rua do Lago 562, Cidade Universitária, São Paulo, 05508-080, Brasil., Philippot P; Géosciences Montpellier, Pl. Eugène Bataillon, Campus Triolet, Université de Montpellier, CNRS, Université des Antilles, 34095, Montpellier, France.; Departamento de Geofísica, Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Universidade de São Paulo, Rua do Matão 1226, Cidade Universitária, São Paulo, 05508-090, Brasil.
Jazyk:	angličtina
Zdroj:	PNAS nexus [PNAS Nexus] 2023 Feb 08; Vol. 2 (3), pp. pgad025. Date of Electronic Publication: 2023 Feb 08 (Print Publication: 2023).
DOI:	10.1093/pnasnexus/pgad025
Abstrakt:	The availability of nutrients in seawater, such as dissolved phosphorus (P), is thought to have regulated the evolution and activity of microbial life in Earth's early oceans. Marine concentrations of bioavailable phosphorus spanning the Archean Eon remain a topic of debate, with variable estimates indicating either low (0.04 to 0.13 μM P) or high (10 to 100 μM P) dissolved P in seawater. The large uncertainty on these estimates reflects in part a lack of clear proxy signals recorded in sedimentary rocks. Contrary to some recent views, we show here that iron formations (IFs) are reliable recorders of past phosphorus concentrations and preserved a primary seawater signature. Using measured P and iron (Fe) contents in Neoarchean IF from Carajás (Brazil), we demonstrate for the first time a clear partitioning coefficient relationship in the P-Fe systematics of this IF, which, in combination with experimental and Archean literature data, permits us to constrain Archean seawater to a mean value of 0.063 ± 0.05 μM dissolved phosphorus. Our data set suggests that low-phosphorus conditions prevailed throughout the first half of Earth's history, likely as the result of limited continental emergence and marine P removal by iron oxyhydroxide precipitation, supporting prior suggestions that changes in ancient marine P availability at the end of the Archean modulated marine productivity, and ultimately, the redox state of Earth's early oceans and atmosphere. Classification: Physical Sciences, Earth, Atmospheric and Planetary Sciences. (© The Author(s) 2023. Published by Oxford University Press on behalf of National Academy of Sciences.)
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu