A comparative study between loss on ignition and total carbon analysis on Late Glacial sediments from Atteköps mosse, southwestern Sweden, and their tentative correlation with the GRIP event stratigraphy

Abstract

Popular abstract: In this study, several sediment core from Atteköps mosse, southwestern Sweden, were investigated with respect to lithostratigraphy, loss on ignition analysis, grain size distribution, magnetic susceptibility, total carbon analysis and 14C dating. The first part of the study foccuses on a detailed analysis of the above mentioned sediment parameters. The results revealed a characteristic pattern with several dominantly minerogenic units separated by units with high organic content. These alternations very likely reflect changing climatic conditions and their impact on the former lake and its catchment, The available radiocarbon dates, comparisons with an earlier, unpublished investigation of Atteköps mosse and correlations with other published sited from southwestern Sweden imply that the investigated sequence was deposited during the Late Glacial and the early Holocene. By correlating the distinct lithological changes to the GRIP event stratigraphy, and assuming that climatic changes in southern Sweden and on Greenland occured more or less synchronous, a tentative chronology for the sequence in Atteköps mosse could be established. Based on the chronological framework, the Late Glacial and early Holocene environmental development of the site is discussed. The second part of the study deals with a comparison between orgaic and carbonate content determinations based on loss on ignition and step-wise total carbon analysis, and a correlation to grain-size. Although loss on ignition can generally be regarded as an accurate measure of the organic matter content of a sediment, the amount of the fine fraction in the sediments is a limiting factor for an absolute organic carbon determination and influences directly the correction factor. The same holds true for carbonate content determinations based on loss on ignition. In order to provide accurate organic and carbonate content determinations for a sediment, loss on ignition data must be corroborated by standard total carbon analysis.

Abstract

In this study, a high resolution loss on ignition analysis was performed over the Late Weichselian lacustrine sediments retrieved from Atteköps mosse, southwestern Sweden. The data set was complemented by grain-size measurements, total carbon analysis, magnetic susceptibility and AMS 14C dates. The analyzed data set reveals a characteristic pattern in lithology and the loss on ignition curve, where several distinct minerogenic units are overlain by organic rich horizons. In order to derive a chronology for the studied sediments, the down-core fluctuations in loss on ignition were compared to earlier analysed, close-by sites on Kullen Peninsula, and tentatively to the GRIP event stratigraphy. These correlations imply that sediments started to accumulate during late GS-2, that the studied sequence extends up to the early holocene and that all major Late Glacial climate fluctuations are represented. Based on the investigated parameters, changes in the lake ecosystem, as response to the climate fluctuations are discussed. Although the absolute values of loss on ignition are subject to several uncertainties, relative down-core changes are useful in interpreting the impact of climatic changes through the sediment sequence. However, if absolute organic determinations are to be made, loss on ignition data must be supported by independent total carbon datermination. Carbonate content determination by means of loss on ignition seems to be strongly influenced by fine sediment fractions. Care must therefore be taken when the ”carbonate content” via loss on ignition is interpreted in terms of a palaeoenvironmental indicator.

Abstract (Swedish)

I denna undersökning har en stratigrafiskt högupplösande glödförluststudie utförts på senglaciala och tidigholocena sjösediment från Atteköps mosse i nordvästra Skåne. Studien har kompletterats med kornstorleksanalyser, kolanalyser, mätningar av magnetisk susceptibilitet och AMS 14C-dateringar.
Undersökningen påvisar ett karaktäristiskt mönster i sedimentens sammansättning och i glödförlustkurvan, på så sätt att ett flertal minerogena enheter överlagras av horisonter rika på
organiskt material. För att upprätta en kronologi över de studerade sedimenten har glödförlustkurvan jämförts med motsvarande kurva för en tidigare studerad och närbelägen lokal på Kullaberg. Glödförlustkurvan har dessutom hypotetiskt korrelerats med den grönländska GRIP-iskärnans händelsestratigrafi. Dessa korreleringar visar att sedimenten i
Atteköps mosse började avsättas under en sen fas av GS-2 under senglacial tid, och att den undersökta delen av lagerföljden tidsmässigt sträcker sig en bit in i tidigholocen tid.
Undersökningen visar också att alla mera omfattande senglaciala klimatfluktuationer finns representerade i lagerföljden. Slutligen diskuteras de senglaciala klimatfluktuationernas påverkan på fornsjöns ekosystem.

• author: Veres, Daniel-Stefan
• supervisor: Barbara Wohlfarth; Svante Björck
• organization: Department of Geology
• alternative title: En jämförande undersökning av glödförlust- och totalkolanalys av senglaciala sediment från Atteköps mosse, sydvästra Sverige, och en möjlig korrelation med GRIP-händelsestratigrafin
• year: 2001
• type: H1 - Master's Degree (One Year)
• subject: Earth and Environmental Sciences
• keywords: Atteköps mosse, limnic sediments, Late Glacial, loss on ignition, total carbon
• publication/series: Dissertations in Geology at Lund University
• report number: 145
• language: English
• id: 2343570
• date added to LUP: 2012-12-04 13:22:53
• date last changed: 2012-12-04 13:22:53