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Characteristics of n-alkanes and hopanes in paleosol layers in the sediment core from Lake Suwa (central Japan) (Supplementary Information)

journal contribution
posted on 2023-09-09, 05:13 authored by Ryosuke Fukuchi, Nozomi Hatano, Hiroyasu Asahi, Ken Sawada

Paleosols are the soils formed on land in the past. Soil profile reflects source materials, microtopography, and climatic and environmental conditions. Although most charactersistics of paleosols have been lost due to erosion and diagenesis, the information for paleoclimatic and paleoenvironmental reconstructions has been recorded in the paleosols. Recently, organic geochemical proxies including biomarkers have been applied to the paleosol study. However, there have been few reports for biomarker variations of paleosols in Japan. The sediment core from Lake Suwa contains some paleosols in lacustrine sediments. The n-alkane proxies such as carbon preference index (CPI) odd to even predominance (OEP) and aquatic plant indicator (Paq) were analyzed. The CPI and OEP values are lower in paleosol layers, but C30 ββ-hopane ratios, a hopanoid biomarker index, are higher. In particular, the CPI values are reversely correlated to the C30 ββ-hopane ratios. From these results, we suggest that n-alkanes with weak odd predominance were presumably derived from plant roots and microbial degradation of long chain, that is odd chain, n-alkanes, and increasing ββ-hopanes, which were fresh biological hopanoids derived from bacteria in the rhizosphere of paleosol layers.


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Title (in Japanese)

諏訪湖堆積物コア中の古土壌層におけるn-アルカン,ホパンの特徴 (Supplementary Information)

Manuscript title (in Japanese)


Authors (in Japanese)

福地 亮介 , 葉田野 希, 朝日 啓泰, 沢田 健


© 2023 日本有機地球化学会

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