堆積物形成過程における有機物の変化 [in Japanese] Change in chemical properties of organic matter during the formation of the lake sediment [in Japanese]
Access this Article
As a part of a study of diagenesis in the lake sediment, total organic carbon, carbohydrate, protein and amino acid, fat (lipid) and humic acid were determined in the core samples with 1.5 m and 200 m length from Lake Suwa and Lake Biwa respectively. It was found that fat shows the great decrease with depth followed by protein and amino acid and then carbohydrate in the surface to subsurface layers of the sediment whereas much slow vertical decrease in these organic materials occurs in further depths of the sediment. The decomposition reaction of the organic matter in the sediment was found to be first order. The decay rate constant was calculated to be n×10<sup>-5</sup> yr.<sup>-1</sup>. Monosaccharide and fatty acid compositions of the sediment from Lake Suwa were deter- mined. It was found that marked change in the composition of these organic materials with depth occurs in the surface to 50 cm depth. To make clear the vertical change in organic materials and their composition, the surface sediment of Lake Suwa was allowed to incubate with or without sodium chloride and carbon dioxide, methane and ammonia produced were measured. The results obtained indicate that decarboxylation and deamination reactions play an important role for the decomposition of organic matter in the surface layer of the lake sediment.
Chikyukagaku 7.8(1), 66-74, 1974
The Geochemical Society of Japan