Bulk characteristics, lipid quantification and compound-specific carbon isotope ratios of Mackenzie Delta lake sediments
The Arctic is undergoing accelerated changes in response to ongoing modifications to the climate system, and there is a need for local to regional scale records of past climate variability in order to put these changes into context. The Mackenzie delta region in northern Canada is populated by numer...
| Main Authors: | , , , , , |
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| Format: | Other/Unknown Material |
| Language: | English |
| Published: |
PANGAEA
2020
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| Subjects: | |
| Online Access: | https://doi.pangaea.de/10.1594/PANGAEA.924201 https://doi.org/10.1594/PANGAEA.924201 |
| Summary: | The Arctic is undergoing accelerated changes in response to ongoing modifications to the climate system, and there is a need for local to regional scale records of past climate variability in order to put these changes into context. The Mackenzie delta region in northern Canada is populated by numerous small shallow lakes. They are classified as no-, low- and high-closure (NC, LC, HC, respectively) lakes, reflecting varying degrees of connection to the river main stem, and have different sedimentation characteristics. This study examines sedimentological (mineral surface area, grain size), carbon isotopic (bulk and molecular-level) and inorganic isotopic (neodymium) characteristics of sediment cores from three lakes representing each class. We find that HC lake sediments exhibit strikingly different properties from the other lake sediments. Specifically, they are characterized by higher organic carbon loadings per unit mineral surface area and with relatively minor influence from allochthonous, petrogenic (rock-derived) organic carbon. In contrast, LC and NC lakes, have the potential to record basin-scale climatic changes at a high resolution by virtue of enhanced detrital sedimentation. Overall the delta have the capacity to bury about 2 MtC yr-1, with little changes since 200 years. |
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