Nitrogen and organic carbon isotope record in Tremadocian highly metalliferous black shales from Baltica

Tremadocian highly metalliferous black shales and associated grey shales from the Aseri PH012B drill core (NE Estonia) in the innermost part of the Baltic Palaeobasin were targeted to record their nitrogen and organic carbon isotope variance combined with the total organic carbon and total nitrogen...

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Bibliographic Details
Main Authors: Mawo Ndiaye, Merlin Liiv, Toivo Kallaste, Sophie Graul, Rutt Hints
Format: Article
Language:English
Published: Estonian Academy Publishers 2023-06-01
Series:Estonian Journal of Earth Sciences
Subjects:
Online Access:https://kirj.ee/wp-content/plugins/kirj/pub/earth-1-2023-78-81_20230612122227.pdf
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Summary:Tremadocian highly metalliferous black shales and associated grey shales from the Aseri PH012B drill core (NE Estonia) in the innermost part of the Baltic Palaeobasin were targeted to record their nitrogen and organic carbon isotope variance combined with the total organic carbon and total nitrogen record. The obtained molar C/N ratios of black shales from 26 to 52 indicate a considerable loss of N compared to primary biomass. The recorded δ15N values from â2.5 to 0.2â° likely evolved due to isotopic fractionation related to N2 fixation by primary producers, superimposed by later anoxic ammonium oxidation processes within the uppermost sediments. The high net primary productivity, which controlled the accumulation of organic-rich shallow-water complexes, was fuelled by the internal cycling of P in the sea basin and combined with intensive N exchange between marine and atmospheric pools.
ISSN:1736-4728
1736-7557