Silicon isotopes in Antarctic sponges: an interlaboratory comparison
Silicon isotopes in Antarctic sponges: an interlaboratory comparison
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DOI：
10.1017/s0954102010000593
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发表时间：
2011-02-01
影响因子：
1.6
通讯作者：
Halliday, Alex N.
中科院分区：
文献类型：
--
作者：
Hendry, Katharine R.;Leng, Melanie J.;Halliday, Alex N.
深水硅（Si）在南大洋内的循环及其向其他海洋盆地的输送可能是吸收大气碳和全球气候的重要因素。最近的工作表明，深海海绵的硅同位素（用δ Si-29或δ Si-30表示）组成反映了生长过程中溶解硅的可用性，是过去深海和中层水硫酸浓度的潜在代表。与任何地球化学工具一样，必须确保分析的精确度和准确性，以及方法和实验室之间的一致性。实验室之间可能存在分析偏差，海绵材料可能具有基质效应，导致样品和标准品之间的偏移。在这里，我们报告了一个实验室间评估的硅同位素在南极和亚南极海绵。我们审查独立的方法测量硅同位素海绵骨针。我们的研究结果表明，通过三种方法测量的非均质海绵的单独子样品产生超过80%的标本的分析误差内的同位素值。海绵中δ Si-29和δ Si-30之间的关系与生物矿化过程中的动力学分馏相一致。海绵硅同位素分析显示潜在的palaeaongraphic档案，我们建议南大洋海绵材料将形成一个有用的额外的参考标准，为未来的骨针分析。
Cycling of deepwater silicon (Si) within the Southern Ocean, and its transport into other ocean basins, may be an important player in the uptake of atmospheric carbon, and global climate. Recent work has shown that the Si isotope (denoted by delta Si-29 or delta Si-30) composition of deep sea sponges reflects the availability of dissolved Si during growth, and is a potential proxy for past deep and intermediate water silicic acid concentrations. As with any geochemical tool, it is essential to ensure analytical precision and accuracy, and consistency between methodologies and laboratories. Analytical bias may exist between laboratories, and sponge material may have matrix effects leading to offsets between samples and standards. Here, we report an interlaboratory evaluation of Si isotopes in Antarctic and sub-Antarctic sponges. We review independent methods for measuring Si isotopes in sponge spicules. Our results show that separate subsamples of non-homogenized sponges measured by three methods yield isotopic values within analytical error for over 80% of specimens. The relationship between delta Si-29 and delta Si-30 in sponges is consistent with kinetic fractionation during biomineralization. Sponge Si isotope analyses show potential as palaeoceaongraphic archives, and we suggest Southern Ocean sponge material would form a useful additional reference standard for future spicule analyses.