Organic geochemical features of an extremely acid crater lake(Yugama) of Kusatsu-Shirane Volcano in Japan.
Organic geochemical features of an extremely acid crater lake(Yugama) of Kusatsu-Shirane Volcano in Japan.
复制标题
日本草津白根火山极酸性火山口湖（汤伽玛）的有机地球化学特征。
DOI：
10.2343/geochemj.26.117
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发表时间：
1992
影响因子：
0.8
通讯作者：
K. Watanuki
中科院分区：
文献类型：
--
作者：
G. Matsumoto;K. Watanuki
对日本草津shirane活火山极酸性火山口湖（Yugama, pH = 1.2）进行了有机地球化学研究，以阐明与生物活性有关的有机组分特征和来源。湖泊悬浮物（≥0.60 μm）、硫团聚体、表层沉积物和湖泊周围土壤中，正构烷烃分布范围从n-C15到n-C36，以长链（n-C20-n-C36）正构烷烃为主，且以n-C27、n-C29和n-C31居多，同时还含有原烷、植烷、角鲨烷、甾烷和/或三萜烷。在所有样品中均发现了以偶碳数为主的n-C8 ~ n-C32型正烷酸，以及正烷酸的顺式和反式异构体[n-C16:1 （Δ7和δ9）和n-C18:1 （Δ9和Δ11）]、异烷酸和前异烷酸（C14-C17）和环丙基烷酸（C17和C19）]。然而，在所有样品中均未发现多烯酸。正常3-羟基酸（n-C10-n-C18）在n-C14位点最大，异-羟基酸和前异-3-羟基酸（C12-C18）最大。湖泊水体和沉积物中有机成分的特征表明，除了某些未培养的细菌外，它们可能是细菌，如硫氧化硫杆菌，并受到湖泊周围含有维管植物碎屑的侵蚀和/或风运物质的影响。低浓度的脂肪酸主要反映了湖泊中光合生产者的缺乏和小的活生物量。较高的反式/顺式- c16:1烯酸比值（0.24 ~ 0.52）可能是由于湖泊环境不利于微生物活动所致。（20S/20R）-24-乙基-5α(H)、14 - α(H)、-17α(H)-胆甾烷比值（0.49 ~ 0.77）和(22S/22R)-17α(H)、21β(H)-30-高藿烷比值（1.0 ~ 1.4）的热成熟参数均未达到平衡值，但可能受到过去热液活动的显著影响。
Organic geochemical study on an extremely acid crater lake (Yugama, pH = 1.2) of an active Kusatsu-Shirane Volcano in Japan has been carried out to clarify the features and sources of organic components in relation to biological activity. Generally, n-alkanes ranging from n-C15 to n-C36 with a predominance of long-chain (n-C20–n-C36) n-alkanes maximizing at n-C27, n-C29 or n-C31 were detected in suspended solids (≥0.60 μm), sulfur aggregate and surface sediments of the lake, and soils in the surroundings of the lake, together with pristane, phytane, squalane, steranes and/or triterpanes. A series of n-alkanoic acids ranging from n-C8 to n-C32 with a predominance of even-carbon numbers were found in all the samples, along with cis- and trans-isomers of n-alkenoic acids [n-C16:1 (Δ7 and δ9) and n-C18:1 (Δ9 and Δ11)], iso- and anteiso-alkanoic acids (C14–C17), and cyclopropyl alkanoic acids (C17 and C19). No polyenoic alkenoic acids were, however, found in all the samples. Normal 3-hydroxy acids (n-C10–n-C18) mainly maximizing at n-C14 were detected, together with iso- and anteiso-3-hydroxy acids (C12–C18). The features of organic components in the lake waters and sediments indicate that they can be attributed to bacteria, such as Thiobacillus thiooxidans in addition to certain uncultured bacteria, with some influences of eroded, and/or wind-transported materials containing vascular plant debris from the surroundings of the lake. Low concentrations of fatty acids mainly reflect the paucity of photosynthetic producers and small living biomass in the lake. Relatively high trans/cis-C16:1 alkenoic acid ratios (0.24–0.52) may be caused by unfavorable habitat for microbial activity in the lake. The thermal maturation parameters of (20S/20R)-24-ethyl-5α(H), 14α(H), -17α(H)-cholestane ratios (0.49–0.77) and (22S/22R)-17α(H), 21β(H)-30-homohopane ratios (1.0–1.4) have not reached equilibrium values, but may have been significantly influenced by hydrothermal activity in the past in Lake Yugama and the surroundings of the lake.