Title :

Major Early-Middle Devonian oceanic oxygenation linked to early land plant evolution detected using high-resolution U isotopes of marine limestones

Author(s) :

Elrick, Maya [Auteur]
The University of New Mexico [Albuquerque]
Gilleaudeau, Geoffrey [Auteur]
George Mason University [Fairfax]
Romaniello, Stephen [Auteur]
The University of Tennessee [Knoxville]
Algeo, Thomas [Auteur]
University of Cincinnati [UC]
Morford, Jennifer [Auteur]
Sabbatino, Monia [Auteur]
Università degli studi di Trieste = University of Trieste
Goepfert, Tyler [Auteur]
Cleal, Christopher [Auteur]
Cascales Minana, Francisco De Borja [Auteur]
Évolution, Écologie et Paléontologie (Evo-Eco-Paleo) - UMR 8198 [Evo-Eco-Paléo (EEP)]
Chernyavskiy, Pavel [Auteur]

Journal title :

Earth and Planetary Science Letters

Pages :

117410

Publisher :

Elsevier

Publication date :

2022

ISSN :

0012-821X

English keyword(s) :

euxinia
seawater redox
middle Paleozoic
terrestrialization

HAL domain(s) :

Planète et Univers [physics]/Océan, Atmosphère
Planète et Univers [physics]/Sciences de la Terre/Climatologie
Planète et Univers [physics]/Sciences de la Terre/Paléontologie

English abstract : [en]

The middle Paleozoic (∼420-350 Myr) records a major increase in ocean-atmosphere oxygen levels; however, the timing and pattern of oxygenation are poorly constrained. Two well-dated North American locations in Nevada and ...
Show more >The middle Paleozoic (∼420-350 Myr) records a major increase in ocean-atmosphere oxygen levels; however, the timing and pattern of oxygenation are poorly constrained. Two well-dated North American locations in Nevada and Illinois were used to generate a high-resolution U-isotopic profile (δ 238 U) spanning ∼70 Myr of the middle Paleozoic. Stratigraphic and geochemical data support the interpretation that the Nevada profile represents a near-primary record of global-ocean redox variations. First-order δ 238 U trends indicate strongly reducing oceans during the late Silurian and Early Devonian, terminated by a major oxygenation event near the Emsian-Eifelian boundary (∼395 Ma). More oxic seawater conditions persisted for the next 30+ Myr, but were punctuated by multiple Myr-scale anoxic events during the Middle-Late Devonian and Early Mississippian that correlate with known global biotic crises, positive δ 13 C excursions, and widespread organic-rich facies deposition. The timing of the ∼395 Ma oxygenation event suggests that the O 2 rise was the result of increased photosynthesis and organic carbon burial linked to diversification of late Silurian to earliest Middle Devonian terrestrial plants, rather than to subsequent Devonian increases in terrestrial plant root depth, tree height, lignin content, or seed reproduction. These findings demonstrate that early colonization of continents by relatively small, shallowly rooted plants with geographically limited ranges was sufficient to drive long-term oxygenation of the ocean-atmosphere system, paving the way for the evolution of large, mobile animals that have dominated the Earth's surface since the middle Paleozoic.Show less >

Language :

Anglais

Popular science :

Non

ANR Project :

Comprendre le verdissement de la Terre primitive

Collections :

• Évolution, Écologie et Paléontologie (Evo Eco Paleo) - UMR 8198

Source :

Harvested from HAL