新古人类碳酸盐相关硫酸盐记录呈阳性 Δ33S 异常
G Paris1, J F Adkins2, A L Sessions2
1Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA. gparis@caltech.edu.
概括
对新古碳酸盐的硫同位素分析揭示了意想不到的正质量独立分离 (Δ(33) S) 信号,挑战了关于早期地球大气和硫酸盐组成的先前假设.
科学领域:
- 地质化学 地质化学
- 古气候学 古气候学
- 早期地球的条件.
背景情况:
- 古代岩石中的硫同位素 (Δ(33) S) 提供了早期大气组成和氧化事件的信息.
- 假设预测负 Δ(33) S 对于古河海水硫酸盐,但这仍然在很大程度上未经测试的大多数古河eon.
研究的目的:
- 为了研究在新古碳酸盐中 Δ(33) S 的特征.
- 为了测试Archean海水硫酸盐中均负 Δ(33) S 的普遍假设.
主要方法:
- 用X射线吸收光谱分析新古碳酸盐中的低硫酸盐含量.
- 质谱测量用于测量硫同位素 (Δ(33) S) 的特征.
主要成果:
- 在新古碳酸盐中检测到意想不到的,大规模和广泛的正 Δ(33) S 值.
- 这些发现涵盖了超过7000万年的时间和不同的沉积环境.
- 硫酸盐记录没有显示大气硫质量独立分离的预期负 Δ(33) S.
结论:
- 古代海水硫酸盐并不总是携带预测的负 Δ(33) S 信号.
- 这挑战了新古时代硫循环和大气组成现有的模型.
- 需要重新评估地球早期大气中的硫质量独立分离过程.
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