Sulfur isotopic composition of superhigh-organic-sulfur coals from the Chenxi coalfield, southern China
Sulfur isotopic composition of superhigh-organic-sulfur coals from the Chenxi coalfield, southern China
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陈西煤田超高有机硫煤的硫同位素组成
DOI：
10.1016/j.coal.2014.02.006
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发表时间：
2014-07-01
影响因子：
5.6
通讯作者：
Tang, Yuegang
中科院分区：
文献类型：
--
作者：
Li, Weiwei;Tang, Yuegang
中国湖南辰溪煤田晚二叠世的超高有机硫（SHOS）煤沉积在碳酸盐潮坪中，并且具有可大于10%（S-o，S-（daf））的有机硫含量。有机硫的δ S-34值在-7.3份/千份和-1.8份/千份之间变化，比黄铁矿硫的δ S-34值在-31.8份/千份和-13.3份/千份之间变化（δ δ S-34（org）= 18.5份/千份）的范围窄（δ δ S-34（org）= 5.5份/千份）。辰溪煤中有机硫和黄铁矿硫的硫同位素组成相对于周围环境中溶解的硫酸盐均明显亏损S-34。晨曦煤中的硫大部分来自海水硫酸盐的细菌还原，部分来自海洋植物。与低硫煤和中硫煤相比，SHOS煤具有不同的硫同位素特征，表明其硫的来源和富集机制存在很大差异。辰溪煤的主要岩石学特征（主要为胶凝碎屑组和大量惰质组）表明，辰溪煤形成于碱性还原环境，细菌活动和间歇性氧化作用并存。提出了硫还原-再氧化-再硫化（SRRD）循环模型，作为硫酸盐细菌还原的补充，解释了辰溪煤中硫的掺入。(C)2014爱思唯尔有限公司版权所有。
The superhigh-organic-sulfur (SHOS) coals of the Late Permian from the Chenxi coalfield, Hunan Province, China are deposited in a carbonate tidal flat and have an organic sulfur content that can be greater than 10% (S-o,S- (daf)). The delta S-34 value of organic sulfur varies between -7.3 parts per thousand and -1.8 parts per thousand, a narrower range (Delta delta S-34(org) = 5.5 parts per thousand) than that of pyritic sulfur, which varies from -31.8 parts per thousand to -13.3 parts per thousand (Delta delta S-34(org) = 18.5 parts per thousand). The sulfur isotopic compositions of both organic and pyritic sulfur in the Chenxi coals were significantly depleted in S-34 relative to the dissolved sulfate in the ambient environment. The majority of sulfur in the Chenxi coals originated from the bacterial reduction of seawater sulfate and partially from marine plants. Compared with the low/medium sulfur coals, the SHOS coals exhibited dissimilar isotopic characteristics, indicating that the sulfur origin and/or enrichment mechanisms were quite different from each other. Petrological characteristics, such as predominant collodetrinite and excessive inertinite, suggest that the Chenxi coal formed in an alkaline reducing environment with bacterial activities and intermittent oxidation processes. A cycle model, consisting of sulfur reduction, reoxidation, and disproportionation (SRRD), was proposed to be a supplement of the sulfate bacterial reduction to explain the incorporation of sulfur into the Chenxi coals. (C) 2014 Elsevier B.V. All rights reserved.