同位素和矿物学偏差是由阿拉贡石粉碎引入的
Katharina E Schmitt1, Laura J Fink1, Anne Jantschke1
1Institute of Geosciences, University of Mainz, Mainz, Germany.
Rapid communications in mass spectrometry : RCM
|June 26, 2024
概括
机器磨砂阿拉贡石可以产生石,改变稳定的同位素数据,这对古气候研究至关重要. 手动研磨的雅砂是唯一可靠的纯阿拉贡石粉的方法.
科学领域:
- 地质化学 地质化学
- 古气候学 古气候学
- 材料科学 材料科学 材料科学
背景情况:
- 对阿拉贡石的稳定碳和氧同位素分析对于古气候研究至关重要.
- 准确的分析需要具有良好的同质化,细粒度的阿拉贡石粉.
- 研磨方法可能会影响样品的均性和矿物相完整性.
研究的目的:
- 评估不同研磨方法对阿拉贡石样本同质性的影响.
- 为了评估在粉碎过程中无意形成石的风险.
- 为了确定研磨对稳定同位素值 (δ18O和δ13C) 的影响.
主要方法:
- 使用各种方法 (钻孔,振动机,木砂) 粉碎生物的 (北极岛屿贝) 和非生物的阿拉贡石.
- 使用粉末X射线衍射 (PXRD),拉曼和ATR-FTIR光谱学分析矿物相.
- 通过PXRD Rietveld精炼和稳定同位素测量的酸盐含量的定量.
主要成果:
- 振动 (3-10分钟) 产生了均的样本.
- 更积极的研磨方法产生了显著的石 (0.5-4.2重量%) 和降低了δ18O和δ13C值,特别是在中.
- 手动在石砂中打是生产纯阿拉贡石粉的唯一方法.
结论:
- 常见的基于机器的粉碎方法无法产生纯色阿拉贡石粉末.
- 这对依赖光稳定同位素的古气候重建有重大影响.
- 使用机床磨砂阿拉贡石时,可能会高估古气温,但手工制备的样本除外.
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