Arctic Deltaic Lake Sediments As Recorders of Fluvial Organic Matter Deposition ...

• Main Authors: Vonk, Jorien, Dickens, Angela F., Giosan, Liviu, Hussain, Zainab A., Kim, Bokyung, Zipper, Samuel C., Holmes, Robert M., Montluçon, Daniel B., Galy, Valier, Eglinton, Timothy I.
• Format: Article in Journal/Newspaper
• Language: English
• Published: ETH Zurich 2016
• Subjects: Lignin; Biomarkers; Carbon isotopes; Lake sediments; Arctic; Mackenzie Delta; Mackenzie river
• Online Access: https://dx.doi.org/10.3929/ethz-b-000121285; http://hdl.handle.net/20.500.11850/121285

Arctic deltas are dynamic and vulnerable regions that play a key role in land-ocean interactions and the global carbon cycle. Delta lakes may provide valuable historical records of the quality and quantity of fluvial fluxes, parameters that are challenging to investigate in these remote regions. Here we study lakes from across the Mackenzie Delta, Arctic Canada, that receive fluvial sediments from the Mackenzie River when spring flood water levels rise above natural levees. We compare downcore lake sediments with suspended sediments collected during the spring flood, using bulk (% organic carbon, % total nitrogen, δ^13C, Δ^14C) and molecular organic geochemistry (lignin, leaf waxes). High-resolution age models (^137Cs, ^210Pb) of downcore lake sediment records (n = 11) along with lamina counting on high-resolution radiographs show sediment deposition frequencies ranging between annually to every 15 years. Down-core geochemical variability in a representative delta lake sediment core is consistent with ... : Frontiers in Earth Science, 4 ...