(87)Sr/(86)Sr evidence from the epeiric Martin Ridge Basin for enhanced carbonate weathering during the Hirnantian

A pronounced positive δ(13)C excursion in the Hirnantian Age has been documented globally, reflecting large perturbations of carbon cycling in the Late Ordovician oceans. Increased organic-carbon burial or enhanced carbonate weathering during glacioeustatic sea-level regression has been proposed to...

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Detalles Bibliográficos
Autores principales: Hu, Dongping, Zhang, Xiaolin, Zhou, Lian, Finney, Stanley C., Liu, Yongsheng, Shen, Danielle, Shen, Megan, Huang, Wei, Shen, Yanan
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2017
Materias:
Article
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5595791/
https://www.ncbi.nlm.nih.gov/pubmed/28900275
http://dx.doi.org/10.1038/s41598-017-11619-w
Descripción
Sumario:A pronounced positive δ(13)C excursion in the Hirnantian Age has been documented globally, reflecting large perturbations of carbon cycling in the Late Ordovician oceans. Increased organic-carbon burial or enhanced carbonate weathering during glacioeustatic sea-level regression has been proposed to account for this anomalous C-isotope excursion. To test the two competing hypotheses, we measured (87)Sr/(86)Sr and δ(13)C of carbonates from the Copenhagen Canyon section in Nevada, USA. Our data reveal two rapid negative (87)Sr/(86)Sr shifts that coincide with two prominent positive δ(13)C excursions and glacial advances. Numerical model simulations suggest that enhanced weathering of carbonates driven by glacio-eustatically controlled sea-level fall is required to produce the observed drops of (87)Sr/(86)Sr and the coeval large positive δ(13)C excursions, possibly with or without increased organic carbon burial.

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