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Carbon cycling with...
Carbon cycling within an East African lake revealed by the carbon isotope composition of diatom silica: a 25-ka record from Lake Challa, Mt. Kilimanjaro
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Barker, Philip A. (author)
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Hurrell, Elizabeth R. (author)
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Leng, Melanie J. (author)
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Plessen, Birgit (author)
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Wolff, Christian (author)
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- Conley, Daniel (author)
- Lund University,Lunds universitet,Kvartärgeologi,Geologiska institutionen,Naturvetenskapliga fakulteten,Quaternary Sciences,Department of Geology,Faculty of Science
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Keppens, Eddy (author)
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Milne, Isla (author)
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Cumming, Brian F. (author)
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Laird, Kathleen R. (author)
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Kendrick, Chris P. (author)
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Wynn, Peter M. (author)
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Verschuren, Dirk (author)
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(creator_code:org_t)
- Elsevier BV, 2013
- 2013
- English.
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In: Quaternary Science Reviews. - : Elsevier BV. - 0277-3791. ; 66, s. 55-63
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https://doi.org/10.1...
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Abstract
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- The carbon cycle of a lake is a balance between supply from the atmosphere and catchment, and the net demand exerted by primary producers, minus losses back to the atmosphere and to sediment storage. Evaluating the sum of these processes and reconstructing them from sediment records of lake history requires a range of methods and a multi-proxy approach. One promising technique is to explore the carbon-isotope composition (delta C-13(diatom)) of organic matter incorporated within the silica frustules of diatom algae. Here we present a 25,000-year record of delta C-13(diatom) from the sediments of crater Lake Challa on the eastern flank of Mt. Kilimanjaro, and along with other proxy data we make inferences about the three major phases in the history of the lake's carbon cycle. From 25 ka to 15.8 ka years BP, delta C-13(diatom) is positively correlated with the delta C-13 of bulk sediment organic matter (delta C-13(bulk)), indicating that high diatom productivity, as recorded by high % biogenic silica at this time, was preferentially removing C-12 and enriching the delta C-13 of lake-water dissolved inorganic carbon. From 15.8 to 5.5 ka the correlation between delta C-13(diatom) and delta C-13(bulk) breaks down, suggesting carbon supply to the lake satisfied or exceeded the demand from productivity. From 5.5 ka BP the positive correlation resumes, indicating an increase in the internal demand for carbon relative to external supply. Diatom frustule-bound carbon isotopes offer an original tool in examining long-term fluctuations in a lake's carbon budget and how the balance between supply and demand has changed through time. (C) 2012 Elsevier Ltd. All rights reserved.
Subject headings
- NATURVETENSKAP -- Geovetenskap och miljövetenskap -- Geologi (hsv//swe)
- NATURAL SCIENCES -- Earth and Related Environmental Sciences -- Geology (hsv//eng)
Keyword
- Diatom frustule carbon
- Carbon isotopes
- Lake carbon cycle
- Lake Challa
- East Africa
- Palaeoclimate
Publication and Content Type
- art (subject category)
- ref (subject category)
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- By the author/editor
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Barker, Philip A ...
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Hurrell, Elizabe ...
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Leng, Melanie J.
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Plessen, Birgit
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Wolff, Christian
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Conley, Daniel
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show more...
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Keppens, Eddy
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Milne, Isla
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Cumming, Brian F ...
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Laird, Kathleen ...
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Kendrick, Chris ...
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Wynn, Peter M.
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Verschuren, Dirk
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show less...
- About the subject
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- NATURAL SCIENCES
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NATURAL SCIENCES
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and Earth and Relate ...
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and Geology
- Articles in the publication
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Quaternary Scien ...
- By the university
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Lund University