DETERMINATION OF BIOGENIC OPAL IN PELAGIC MARINE SEDIMENTS : A SIMPLE METHOD REVISITED
DETERMINATION OF BIOGENIC OPAL IN PELAGIC MARINE SEDIMENTS : A SIMPLE METHOD REVISITED
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远洋海洋沉积物中生物蛋白石的测定：重新审视简单方法
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
Lyle
中科院分区：
文献类型：
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作者：
Á.;O. Lyle;M.;Lyle
进行了一项实验室研究，以确定使用2 M碳酸钠（Na 2CO 3）溶液消化放射虫丰富的始新世和中新世样品，以找到他们的总蛋白石含量的充分性。一般来说，这种常用的方法不足以完全消化，即使消化时间几乎是三倍。然而，消化没有进行到完成时，2-M氢氧化钾（KOH）溶液是取代的碳酸钠试剂和消化进行8.5-10小时。除了当火山灰存在，2-M KOH消化产生更准确的生物硅结果古近系样品具有高蛋白石含量比碳酸钠浸出。这一结论是基于生物硅的结果获得了一个独立的分析方法（规范分析）的古近系放射虫丰富的样品。更重要的是，KOH处理似乎不会以足以损害结果的相对准确度的浓度从基质组分（如粘土矿物和其他碎硅质）中浸出“过量二氧化硅”。相比之下，Na 2CO 3沥滤大大低估了古近系样品中生物硅的量。对于含有火山灰的样品，这两种处理方法都高估了生物二氧化硅的含量，KOH处理产生的值比Na 2CO 3沥滤大两到三倍。常用的2-M Na 2CO 3浸出不足以快速消化放射虫的生物蛋白石（例如，Leg 199沉积物），但2-M KOH溶液将产生相当准确的结果。1如何引用本卷的全部或部分的示例。2美国博伊西州立大学浅层地下地球物理研究中心，博伊西ID 83725。通讯作者：mlyle@cgiss.boisestate.edu
A laboratory study was conducted to determine the adequacy of using a 2-M sodium carbonate (Na2CO3) solution to digest radiolarianrich Eocene and Miocene samples to find their total opal content. In general, this commonly used method is not sufficient for complete digestion, even when digestion times are nearly tripled. However, digestion does proceed to completion when a 2-M potassium hydroxide (KOH) solution is substituted for the Na2CO3 reagent and digestion proceeds for 8.5–10 hr. Except when volcanic ash is present, a 2-M KOH digestion produced more accurate biogenic silica results for Paleogene samples with a high opal content than did a Na2CO3 leach. This conclusion is based on biogenic silica results obtained by an independent method of analysis (normative analysis) for Paleogene radiolarian-rich samples. More importantly, the KOH treatment does not appear to leach “excess silica” from the matrix components (such as clay minerals and other siliciclastics) in sufficient concentrations to compromise the relative accuracy of the results. In contrast, the Na2CO3 leach greatly underestimates the amount of biogenic silica in the Paleogene samples. For samples containing volcanic ash, both treatments overestimate the amount of biogenic silica present, with the KOH treatment producing values two to three times greater than the Na2CO3 leach. The commonly used 2-M Na2CO3 leach is inadequate for the rapid digestion of biogenic opal for radiolarians (e.g., Leg 199 sediments), but a 2-M KOH solution will produce reasonably accurate results. 1Examples of how to reference the whole or part of this volume. 2Center for Geophysical Investigation of the Shallow Subsurface, Boise State University, Boise ID 83725, USA. Correspondence author: mlyle@cgiss.boisestate.edu