概括
卡尔卡入侵显示了复杂的开放系统行为,同位素数据显示了巨大的国家岩石污染和可变的岩组成,挑战了层层入侵的简单分量结晶模型.
科学领域:
- 地质学
- 地质化学
- 石油学
背景情况:
- 卡尔卡入,是澳大利亚中部的吉尔斯综合体的一部分,呈现出从火石到石的层次结构.
- 它的21个循环单位表明分数结晶,但同位素数据表明一个更复杂的过程.
研究的目的:
- 调查卡尔卡入侵的岩过程和污染史.
- 挑战传统的对不同层次的黑人-超黑人入侵的解释.
主要方法:
- 分析初始的 (Sr) 和 (Nd) 的同位素比率.
- 检查矿物质结晶序列和组成变化.
主要成果:
- 起初高的87Sr/86Sr比率和正常的143Nd/144Nd比率表明该国岩石受到严重污染.
- 一个广泛的Sr初始比率 (0.70490.7088) 表明岩组成的变化超出了分离.
结论:
- 卡尔卡入侵是通过复杂的开放系统过程形成的, 而不是简单的分数结晶.
- 同位素异质性表明大量的污染和/或多种团的沉积.
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