FORMATION OF PYRITE IN FRESH-WATER SEDIMENTS - IMPLICATIONS FOR C/S RATIOS
FORMATION OF PYRITE IN FRESH-WATER SEDIMENTS - IMPLICATIONS FOR C/S RATIOS
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DOI：
10.1016/0016-7037(85)90266-2
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发表时间：
1985-01-01
影响因子：
5
通讯作者：
HILTON, J
中科院分区：
文献类型：
--
作者：
DAVISON, W;LISHMAN, JP;HILTON, J
直接测定了 3 个不同营养状态湖泊沉积物中黄铁矿、酸性挥发性硫化物 (AVS)、C 和总 S (St) 的垂直分布。结果表明，淡水黄铁矿的形成反映了沉积物或上覆水域的氧化还原状态。它似乎主要是在还原沉积物中形成的，这些沉积物受到氧化影响，要么是有机碳的低周转，要么是氧气的周期性侵入。尽管高产湖泊的近地表沉积物中 AVS 浓度很高，但很少有成岩作用转化为黄铁矿。评估了使用 S 比来诊断岩石是否在海洋或淡水环境中形成的可行性。 FeS2/FeS 的新值 0.5-5 表明该比率不能提供可靠的测试。 C/Sp 值（其中 Sp 代表黄铁矿 S）在 160-700 范围内，并且远高于之前测量的 1-50 的 C/St 比率。这些新的测定结果表明，如果明确测量黄铁矿 S，C/S 比可能是比以前认为的更敏感的盐度指标。
The vertical distribution of pyrite, acid volatile sulfide (AVS), C, and total S (St) were determined directly in the sediments of 3 lakes of different trophic status. The results showed that freshwater pyrite formation reflects the redox status of the sediment or overlying waters. It appears to form chiefly in reducing sediments which are subject to oxidizing influences, by either a low turnover of organic C or periodic incursions of O2. Although there are high concentrations of AVS in the near-surface sediments of productive lakes, very little is diagenetically converted to pyrite. The feasibility of using S ratios to diagnose whether rocks were formed in marine or freshwater environments is assessed. New values for FeS2/FeS of 0.5-5 show that this ratio does not provide a reliable test. Values of C/Sp, where Sp represents pyrite S, lie within the range of 160-700 and are much higher than previously measured ratios of C/St of 1-50. These new determinations show that, if pyrite S is unequivocally measured, C/S ratios may be a more sensitive indicator of salinity than was previously thought.