The minor sulfur isotope composition of Cretaceous and Cenozoic seawater sulfate
The minor sulfur isotope composition of Cretaceous and Cenozoic seawater sulfate
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DOI：
10.1002/2016pa002945
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发表时间：
2016-06
期刊：
影响因子：
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通讯作者：
A. Masterson;B. Wing;A. Paytan;J. Farquhar;D. Johnston
中科院分区：
文献类型：
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作者：
A. Masterson;B. Wing;A. Paytan;J. Farquhar;D. Johnston
最后的125迈尔记录了海洋化学成分的主要变化以及相关的地球化学和生物地球化学循环。海相重晶石中海水硫酸盐的硫同位素组成是这段时间内较为复杂的地球化学记录之一。许多分析和地球化学建模方法都针对这一记录。在本研究中，我们扩展了海水硫酸盐的经验同位素记录，因此包括了两个次要的硫同位素，33S和36s。这些数据记录了Δ33S和Δ36S平均值周围的值分布为0.043±0.016‰和- 0.39±0.15‰，无论基于δ 34s的分节策略如何，这与整个区间内的值的信号总体一致。我们用简单的盒子模型证明，黄铁矿埋藏和硫酸盐蒸发岩风化的实质性变化可以在我们观察到的同位素值范围内适应。
The last 125 Myr capture major changes in the chemical composition of the ocean and associated geochemical and biogeochemical cycling. The sulfur isotopic composition of seawater sulfate, as proxied in marine barite, is one of the more perplexing geochemical records through this interval. Numerous analytical and geochemical modeling approaches have targeted this record. In this study we extend the empirical isotope record of seawater sulfate to therefore include the two minor sulfur isotopes,33S and36S. These data record a distribution of values around means of Δ33S and Δ36S of 0.043 ± 0.016‰ and −0.39 ± 0.15‰, which regardless ofδ34S‐based binning strategy is consistent with a signal population of values throughout this interval. We demonstrate with simple box modeling that substantial changes in pyrite burial and evaporite sulfate weathering can be accommodated within the range of our observed isotopic values.