Detrital neodymium and (radio)carbon as complementary sedimentary bedfellows? The Western Arctic Ocean as a testbed
| Autor: | H. Rodger Harvey, Jörg Rickli, Negar Haghipour, Robie W. Macdonald, Timothy I. Eglinton, Melissa S. Schwab |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Total organic carbon
chemistry.chemical_classification geography Provenance geography.geographical_feature_category 010504 meteorology & atmospheric sciences Earth science Sediment Western Arctic Ocean Organic carbon Carbon-14 Neodymium isotopes Strontium isotopes Detrital sediments 010502 geochemistry & geophysics 01 natural sciences Continental margin Arctic chemistry 13. Climate action Geochemistry and Petrology Sea ice Environmental science Organic matter Sedimentary rock 14. Life underwater 0105 earth and related environmental sciences |
| Zdroj: | Geochimica et Cosmochimica Acta, 315 |
| ISSN: | 0016-7037 |
| Popis: | Interactions between organic and detrital mineral phases strongly influence both the dispersal and accumulation of terrestrial organic carbon (OC) in continental margin sediments. Yet the complex interplay among biological, chemical, and physical processes limits our understanding of how organo-mineral interactions evolve during sediment transfer and burial. In particular, diverse OC sources and complex hydrodynamic processes hinder the assessment of how the partnership of organic matter and its mineral host evolves during supply and dispersal over continental margins. In this study, we integrate new and compiled sedimentological (grain size, surface area), organic (%OC, OC-δ13C, OC-F14C), and inorganic isotopic (εNd, 87Sr/86Sr) geochemical data for a broad suite of surface sediments spanning the Western Arctic Ocean from the Bering Sea to the Mackenzie River Delta that capture diverse sources and ages of both terrestrial and marine material deposited in contrasting shelf and slope settings. Spatial gradients in sediment properties were used to delineate regional sources and transport processes influencing the dispersion and persistence of OC-mineral particle associations during export and burial. We found strong relationships between physical parameters, aluminum content, and OC-14C suggesting that terrestrial OC remains tightly associated with its detrital mineral carrier during source-to-sink transport. Notably, carbon and neodymium isotopic data yield consistent information regarding organic matter provenance. Results obtained highlight the potential for coupled organic-inorganic tracer measurements to elucidate sediment sources and to constrain physical and geochemical processes during sediment mobilization and transport in the Western Arctic Ocean. Tandem measurements of carbon and Nd isotopes may provide a new way to identify large-scale biogeochemical and ecological changes in the sources, nature, and fate of OC stemming from predicted increases in sea ice loss and fluvial inputs of dissolved and particulate OC to this complex and dynamic high latitude marginal sea. ISSN:0016-7037 ISSN:1872-9533 |
| Databáze: | OpenAIRE |
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