核心-地幔边界的低温度是从火石岩的固体中推断出来的
Ryuichi Nomura1, Kei Hirose, Kentaro Uesugi
1Department of Earth and Planetary Sciences, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan.
概括
地球的地幔固体温度在核心-地幔边界附近令人惊地低. 这一发现为核心-地幔边界温度设定了上限,影响了我们对地球深层过程的理解.
科学领域:
- 地质物理学 地质物理学
- 矿物物理 矿物物理
- 行星科学 行星科学
背景情况:
- 地球地幔的融化温度对于理解地球内部的热结构至关重要.
- 以前对核心-地幔边界温度的估计存在不确定性.
研究的目的:
- 为了确定原始地幔的固体温度在与核心-地幔界限相关的高压下.
- 为了确定一个更精确的温度在核心-地幔边界 (T(CMB)) 的上限.
主要方法:
- 进行高压实验以模拟地球深层条件.
- 使用三维X射线微观图像成像来分析矿物相.
主要成果:
- 发现原始 (火石) 地幔的固体温度在核心-地幔边界压力下低至3570±200克尔文.
- 这种较低的固体温度意味着最下层的地幔并没有全球融化.
- 对于T ((CMB) 的确定的上限表明,在最下层地幔的广泛区域中存在矿后阶段.
结论:
- 显著低的T ((CMB) 要求外核的化温度被污染物,如气,显著降低.
- 这些发现完善了地球热演变和深层内部组成的模型.
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