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Highly fractionated chromium isotopes in Mesoproterozoic-aged shales and atmospheric oxygen

The history of atmospheric oxygen through the Mesoproterozoic Era is uncertain, but may have played a role in the timing of major evolutionary developments among eukaryotes. Previous work using chromium isotopes in sedimentary rocks has suggested that Mesoproterozoic Era atmospheric oxygen levels we...

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Detalles Bibliográficos
Autores principales: Canfield, Donald E., Zhang, Shuichang, Frank, Anja B., Wang, Xiaomei, Wang, Huajian, Su, Jin, Ye, Yuntao, Frei, Robert
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6054612/
https://www.ncbi.nlm.nih.gov/pubmed/30030422
http://dx.doi.org/10.1038/s41467-018-05263-9
Descripción
Sumario:The history of atmospheric oxygen through the Mesoproterozoic Era is uncertain, but may have played a role in the timing of major evolutionary developments among eukaryotes. Previous work using chromium isotopes in sedimentary rocks has suggested that Mesoproterozoic Era atmospheric oxygen levels were too  low in concentration (<0.1% of present-day levels (PAL)) for the expansion of eukaryotic algae and for the evolution of crown-group animals that occurred later in the Neoproterozoic Era. In contrast, our new results on chromium isotopes from Mesoproterozoic-aged sedimentary rocks from the Shennongjia Group from South China is consistent with atmospheric oxygen concentrations of >1% PAL and thus the possibility that a permissive environment existed long before the expansion of various eukaryotic clades.