Fourier transform infrared spectroscopy as a tracer of organic matter sources in lake sediments

dc.contributor.authorMaxson IV, C.
dc.contributor.authorTibby, J.
dc.contributor.authorMarshall, J.
dc.contributor.authorKent, M.
dc.contributor.authorTyler, J.
dc.contributor.authorBarr, C.
dc.contributor.authorMcGregor, G.
dc.contributor.authorCadd, H.
dc.contributor.authorSchulz, C.
dc.contributor.authorLomax, B.H.
dc.date.issued2021
dc.description.abstractThe source of sedimentary organic matter in lakes can help to elucidate climate and catchment variation and processes that reflect lake development. Common techniques for tracing sediment organic matter sources, such as the stable isotopes and elemental concentrations of C and N, can be too imprecise to identify the specific provenance of organic matter. By contrast, organic geochemical techniques such as gas or liquid chromatography and nuclear magnetic resonance provide detailed organic molecular characterisation but are both expensive and time consuming. Fourier Transform Infrared (FTIR) spectroscopy is a rapid, non-destructive, and well-established method for determining the constituents of lake sediments. However, the potential for identifying the sources of organic matter in lake sediments has not been fully explored. In this study, we assess the extent to which FTIR can be used to identify varying organic matter sources through analysis of modern autotrophs from Blue Lake, North Stradbroke Island, Australia. We investigated spectral processing techniques to identify the approach that could most accurately classify autotroph samples. Three autotroph groups (i.e algae, aquatic macrophytes, and terrestrial) were correctly classified 90% of the time. Processed spectra then became the basis of a model that used multivariate random forests to estimate sediment organic matter composition source from a sediment record from Blue Lake that spans the last 7500 years. FTIR-based estimates suggested that throughout the history of the lake, algae contributed the highest amount of organic matter to the sediment samples. These results allow a refinement of a previous study of C:N and δ¹³C from the same core and suggests that alterations in C:N and, particularly, δ¹³C reflect chemical changes in algae through time. This study demonstrates that FTIR spectroscopy is a promising tool to elucidate sources of sediment organic matter in lake sediments.
dc.description.statementofresponsibilityCharles Maxson, John Tibby, Jonathan Marshall, Matthew Kent, Jonathan Tyler, Cameron Barr, Glenn McGregor, Haidee Cadd, Cameron Schulz, Barry H. Lomax
dc.identifier.citationPalaeogeography, Palaeoclimatology, Palaeoecology, 2021; 581:110622-1-110622-11
dc.identifier.doi10.1016/j.palaeo.2021.110622
dc.identifier.issn0031-0182
dc.identifier.issn1872-616X
dc.identifier.orcidMaxson IV, C. [0000-0003-0092-7802]
dc.identifier.orcidTibby, J. [0000-0002-5897-2932]
dc.identifier.orcidTyler, J. [0000-0001-8046-0215]
dc.identifier.orcidBarr, C. [0000-0003-0436-8702]
dc.identifier.orcidCadd, H. [0000-0001-5770-3557]
dc.identifier.urihttps://hdl.handle.net/2440/133568
dc.language.isoen
dc.publisherElsevier BV
dc.relation.granthttp://purl.org/au-research/grants/arc/DP150103875
dc.relation.granthttp://purl.org/au-research/grants/arc/DP190102782
dc.relation.granthttp://purl.org/au-research/grants/arc/LP0990124
dc.rights© 2021 Elsevier B.V. All rights reserved.
dc.source.urihttps://doi.org/10.1016/j.palaeo.2021.110622
dc.titleFourier transform infrared spectroscopy as a tracer of organic matter sources in lake sediments
dc.typeJournal article
pubs.publication-statusPublished

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