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| Titel |
The potential of carbon and nitrogen isotopes to conservatively discriminate between subsoil sediment sources |
| VerfasserIn |
J. Patrick Laceby, Jon Olley |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250075106
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| Zusammenfassung |
| Moreton Bay, in South East Queensland, Australia, is a Ramsar wetland of international
significance. A decline of the bay’s ecosystem health has been primarily attributed to
sediments and nutrients from catchment sources. Sediment budgets for three catchments
indicated gully erosion dominates the supply of sediment in Knapp Creek and the
Upper Bremer River whereas erosion from cultivated soils is the primary sediment
source in Blackfellow Creek. Sediment tracing with fallout-radionuclides confirmed
subsoil erosion processes dominate the supply of sediment in Knapp Creek and the
Upper Bremer River whereas in Blackfellow Creek cultivated and subsoil sources
contribute >90% of sediments. Other sediment properties are required to determine the
relative sediment contributions of channel bank, gully and cultivated sources in these
catchments.
The potential of total organic carbon (TOC), total nitrogen (TN), and carbon and nitrogen
stable isotopes (δ13C, δ15N) to conservatively discriminate between subsoil sediment sources
is presented. The conservativeness of these sediment properties was examined through
evaluating particle size variations in depth core soil samples and investigating whether they
remain constant in source soils over two sampling occasions. Varying conservative behavior
and source discrimination was observed. TN in the |
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