Determination of carbonate and organic matter in calcareous sediments and sedimentary rocks by loss on ignition; comparison with other methods
01 Mar 1974-Journal of Sedimentary Research (Society for Sedimentary Geology)-Vol. 44, Iss: 1, pp 242-248
TL;DR: In this article, a modified ignition loss method is described for determining organic and carbonate carbon in calcareous sedimentary materials using equipment found in most laboratories and has been found to equal or excel the accuracy and precision of other methods tested and has the advantage of being considerably faster if large numbers of samples are to be analyzed.
Abstract: A modified ignition loss method is described for determining organic and carbonate carbon in calcareous sedimentary materials using equipment found in most laboratories. The method has been found to equal or excel the accuracy and precision of other methods tested and has the advantage of being considerably faster if large numbers of samples are to be analyzed.
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TL;DR: In this paper, five test runs were performed to assess possible bias when performing the loss on ignition (LOI) method to estimate organic matter and carbonate content of lake sediments.
Abstract: Five test runs were performed to assess possible bias when performing the loss on ignition (LOI) method to estimate organic matter and carbonate content of lake sediments. An accurate and stable weight loss was achieved after 2 h of burning pure CaCO3 at 950 °C, whereas LOI of pure graphite at 530 °C showed a direct relation to sample size and exposure time, with only 40-70% of the possible weight loss reached after 2 h of exposure and smaller samples losing weight faster than larger ones. Experiments with a standardised lake sediment revealed a strong initial weight loss at 550 °C, but samples continued to lose weight at a slow rate at exposure of up to 64 h, which was likely the effect of loss of volatile salts, structural water of clay minerals or metal oxides, or of inorganic carbon after the initial burning of organic matter. A further test-run revealed that at 550 °C samples in the centre of the furnace lost more weight than marginal samples. At 950 °C this pattern was still apparent but the differences became negligible. Again, LOI was dependent on sample size. An analytical LOI quality control experiment including ten different laboratories was carried out using each laboratory's own LOI procedure as well as a standardised LOI procedure to analyse three different sediments. The range of LOI values between laboratories measured at 550 °C was generally larger when each laboratory used its own method than when using the standard method. This was similar for 950 °C, although the range of values tended to be smaller. The within-laboratory range of LOI measurements for a given sediment was generally small. Comparisons of the results of the individual and the standardised method suggest that there is a laboratory-specific pattern in the results, probably due to differences in laboratory equipment and/or handling that could not be eliminated by standardising the LOI procedure. Factors such as sample size, exposure time, position of samples in the furnace and the laboratory measuring affected LOI results, with LOI at 550 °C being more susceptible to these factors than LOI at 950 °C. We, therefore, recommend analysts to be consistent in the LOI method used in relation to the ignition temperatures, exposure times, and the sample size and to include information on these three parameters when referring to the method.
4,163 citations
Cites background or methods from "Determination of carbonate and orga..."
...Again, higher loss of structural water, volatile salts or inorganic carbon due to warmer temperatures in the centre of the furnace and quicker heating of smaller samples are deemed to be the most likely explanation for the differential weight loss due to positioning of samples in the furnace and to…...
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...Sequential loss on ignition (LOI) is a common and widely used method to estimate the organic and carbonate content of sediments (e.g., Dean, 1974; Bengtsson & Enell, 1986)....
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...…time and sample size In the first two test runs, we exposed samples of pure graphite (Merck #104206, Merck KgaA, Darmstadt, Germany) and of pure calcium carbonate (CaCO 3 , Merck #102064) to 530 and 950 °C to assess if the reactions are complete within the 2 h we previously used for LOI analysis....
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01 Jan 2002
TL;DR: The organic matter content of lake sediments provides a variety of indicators, or proxies, that can be used to reconstruct paleoenvironments of lakes and their watersheds and to infer histories of regional climate changes as mentioned in this paper.
Abstract: The organic matter content of lake sediments provides a variety of indicators, or proxies, that can be used to reconstruct paleoenvironments of lakes and their watersheds and to infer histories of regional climate changes. Organic matter constitutes a minor but important fraction of lake sediments. It originates from the complex mixture of lipids, carbohydrates, proteins, and other organic matter components produced by organisms that have lived in and around the lake (e.g., Meyers, 1997; Rullkotter, 2000). As an accumulation of “geochemical fossils”, the organic matter content of lake sediments provides information that is important to interpretations of both natural and human-induced changes in local and regional ecosystems.
807 citations
Cites background from "Determination of carbonate and orga..."
...Weight loss on ignition (LOI) is also sometimes used to estimate how much organic matter is present in sediments ( Dean, 1974 )....
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TL;DR: In this article, the authors presented the most up-to-date information about the physical environment of the Kongsfjord system and identified important gaps in knowledge, focusing on steep physical gradients along the main fjord axis, as well as seasonal environmental changes.
Abstract: Kongsfjorden-Krossfjorden and the adjacent West Spitsbergen Shelf meet at the common mouth of the two fjord arms. This paper presents our most up-to-date information about the physical environment of this fjord system and identifies important gaps in knowledge. Particular attention is given to the steep physical gradients along the main fjord axis, as well as to seasonal environmental changes. Physical processes on different scales control the large-scale circulation and small-scale (irreversible) mixing of water and its constituents. It is shown that, in addition to the tide, run-off (glacier ablation, snowmelt, summer rainfall and ice calving) and local winds are the main driving forces acting on the upper water masses in the fjord system. The tide is dominated by the semi-diurnal component and the freshwater supply shows a marked seasonal variation pattern and also varies interannually. The wind conditions are characterized by prevailing katabatic winds, which at times are strengthened by the geostrophic wind field over Svalbard. Rotational dynamics have a considerable influence on the circulation patterns within the fjord system and give rise to a strong interaction between the fjord arms. Such dynamics are also the main reason why variations in the shelf water density field, caused by remote forces (tide and coastal winds), propagate as a Kelvin wave into the fjord system. This exchange affects mainly the intermediate and deep water, which is also affected by vertical convection processes driven by cooling of the surface and brine release during ice formation in the inner reaches of the fjord arms. Further aspects covered by this paper include the geological and geomorphological characteristics of the Kongsfjorden area, climate and meteorology, the influence of glaciers, freshwater supply, sea ice conditions, sedimentation processes as well as underwater radiation conditions. The fjord system is assumed to be vulnerable to possible climate changes, and thus is very suitable as a site for the demonstration and investigation of phenomena related to climate change.
781 citations
Book•
01 Jan 2002
TL;DR: The second edition of the Rosetta Stone has been published by as discussed by the authors, which is used to calibrate indicators to environmental variables using surface-sediment training sets, such as ozone depletion, acid rain, and climatic warming.
Abstract: Preface to the second edition. About the author. 1 There is no substitute for water. 2 How long is long?. 3 Sediments: an ecosystem's memory. 4 Retrieving the sedimentary archive and establishing the geochronological clock: collecting and dating sediment cores. 5 Reading the records stored in sediments: the present is a key to the past. 6 The paleolimnologist's Rosetta Stone: calibrating indicators to environmental variables using surface-sediment training sets. 7 Acidification: finding the "smoking gun". 8 Metals, technological development, and the environment. 9 Persistent organic pollutants: industrially synthesized chemicals "hopping" across the planet. 10 Mercury - "the metal that slipped away". 11 Eutrophication: the environmental consequences of over-fertilization. 12 Erosion: tracking the accelerated movement of material from land to water. 13 Species invasions, biomanipulations, and extirpations. 14 Greenhouse gas emissions and a changing atmosphere: tracking the effects of climatic change on water resources. 15 Ozone depletion, acid rain, and climatic warming: the problems of multiple stressors. 16 New problems, new challenges. 17 Paleolimnology: a window on the past, a key to our future. Glossary. References. Index
673 citations
TL;DR: In this article, a 6-year balance computed from continuous net ecosystem CO2 exchange (NEE), regular instantaneous measurements of methane (CH4) emissions, and export of dissolved organic C (DOC) from a northern ombrotrophic bog is presented.
Abstract: Northern peatlands contain up to 25% of the world’s soil carbon (C) and have an estimated annual exchange of CO2-C with the atmosphere of 0.1–0.5 Pg yr � 1 and of CH4-C of 10–25 Tg yr � 1 . Despite this overall importance to the global C cycle, there have been few, if any, complete multiyear annual C balances for these ecosystems. We report a 6-year balance computed from continuous net ecosystem CO2 exchange (NEE), regular instantaneous measurements of methane (CH4) emissions, and export of dissolved organic C (DOC) from a northern ombrotrophic bog. From these observations, we have constructed complete seasonal and annual C balances, examined their seasonal and interannual variability, and compared the mean 6-year contemporary C exchange with the apparent C accumulation for the last 3000 years obtained from C density and agedepth profiles from two peat cores. The 6-year mean NEE-C and CH4-C exchange, and net DOC loss are � 40.2 � 40.5 (� 1 SD), 3.7 � 0.5, and 14.9 � 3.1 g m � 2 yr � 1 , giving a 6-year mean balance of � 21.5 � 39.0 g m � 2 yr � 1 (where positive exchange is a loss of C from the ecosystem). NEE had the largest magnitude and variability of the components of the C balance, but DOC and CH4 had similar proportional variabilities and their inclusion is essential to resolve the C balance. There are large interseasonal and interannual ranges to the exchanges due to variations in climatic conditions. We estimate from the largest and smallest seasonal exchanges, quasi-maximum limits of the annual C balance between 50 and � 105 g m � 2 yr � 1 . The net C accumulation rate obtained from the two peatland cores for the interval 400–3000 BP (samples from the anoxic layer only) were 21.9 � 2.8 and 14.0 � 37.6 g m � 2 yr � 1 , which are not significantly different from the 6-year mean con
627 citations
Cites methods from "Determination of carbonate and orga..."
...Samples (1 cm3) of fresh peat were dried at 105 1C, weighed, and ignited at 600 1C, to determine density and organic matter content (Dean, 1974; Beaudoin, 2003)....
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...Samples (1 cm(3)) of fresh peat were dried at 105 1C, weighed, and ignited at 600 1C, to determine density and organic matter content (Dean, 1974; Beaudoin, 2003)....
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