About this Research Topic
The nitrogen stable isotope composition in sedimentary rocks (δ15N) is increasingly used in deep-time studies for reconstructing changes in biogeochemical cycles and/or water column redox structure, both being intimately linked. Recent analytical advances in EA-IRMS systems have greatly decreased the δ15N measurement time, complexity, and detection limit, while allowing simultaneous δ13C measurements, making the δ15N proxy a standard procedure in paleo-environmental studies. It is thus timely to explore in greater detail the uncertainties that remain in its use. For example, many of our current interpretations of the sedimentary rock record rely heavily on analogies with the modern ocean, while only a handful of aquatic systems presenting analogies with deep-time environments have been investigated for their N-cycle and resulting sedimentary δ15N record. Another major knowledge gap is that, while it is well known that most deep-time sedimentary archives have undergone extensive post-depositional alteration, comparatively little is known about their putative impact on the preservation of primary δ15N signatures.
The aim of this Research Topic is to deepen our understanding of the potential of the δ15N proxy for paleo-environmental reconstructions, to better define its limits, to foster a greater awareness of analytical challenges, sampling representativity, post-depositional processes and other limitations, as well as the development of more nuanced interpretations and research questions.
We welcome submissions of Original Research, Methodology and Review articles that aim to further develop and refine the applicability of the δ15N isotope tool in sedimentary rocks for paleo-environmental reconstructions for time periods ranging from Cretaceous to Archean as well as for the understanding of post-depositional processes. Areas to be covered may include, but are not limited to:
• Case studies of δ15N coupled to other tracers in Archean to Mesozoic sedimentary series;
• Modern analogue studies investigating how different types of the N-cycle are recorded in their sediment δ15N;
• Studies addressing how post-depositional processes impact sediments δ15N;
• Methodological developments in δ15N measurements;
• Laboratory experiments investigating the N-isotope fractionation associated with metabolic or diagenetic processes;
• Models of the past N-biogeochemical cycle predicting sedimentary δ15N values.
The aim of this Research Topic is to deepen our understanding of the potential of the δ15N proxy for paleo-environmental reconstructions, to better define its limits, to foster a greater awareness of analytical challenges, sampling representativity, post-depositional processes and other limitations, as well as the development of more nuanced interpretations and research questions.
We welcome submissions of Original Research, Methodology and Review articles that aim to further develop and refine the applicability of the δ15N isotope tool in sedimentary rocks for paleo-environmental reconstructions for time periods ranging from Cretaceous to Archean as well as for the understanding of post-depositional processes. Areas to be covered may include, but are not limited to:
• Case studies of δ15N coupled to other tracers in Archean to Mesozoic sedimentary series;
• Modern analogue studies investigating how different types of the N-cycle are recorded in their sediment δ15N;
• Studies addressing how post-depositional processes impact sediments δ15N;
• Methodological developments in δ15N measurements;
• Laboratory experiments investigating the N-isotope fractionation associated with metabolic or diagenetic processes;
• Models of the past N-biogeochemical cycle predicting sedimentary δ15N values.
Keywords: nitrogen isotopes, paleobiosphere, paleoceanography, modern analogue, diagenesis
Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.
