从碳酸盐岩石过渡到水热盐水:连续稀释或液体溶解?
Xueyin Yuan1, Richen Zhong2, Xin Xiong1
1MNR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China.
Science advances
|July 19, 2023
概括
高压和高温将碳酸融化转化为热水盐水,这对于理解碳酸中稀土元素 (REE) 矿石体的形成至关重要.
科学领域:
- 地质化学 地质化学
- 矿物学是一门学科.
- 石化学 石化学是一门学科.
背景情况:
- 碳酸盐是稀土元素 (REEs) 的主要来源.
- 从碳酸性岩过渡到热水盐水的过程尚不清楚.
- 分数结晶使融中含有挥发性物质,和REEs.
研究的目的:
- 研究Na2CO3-H2O系统的压力-温度-组成 (P-T-X) 特性.
- 澄清从碳酸盐岩石到水热盐水的过渡过程.
- 了解碳酸盐系统中的REE丰富机制.
主要方法:
- 使用了水热钻石天电池.
- 采用拉曼光谱法进行分析.
- 在高达700°C的温度和高达11.0 kbar.的压力下研究了Na2CO3-H2O系统.
主要成果:
- 在高P-T条件下,碳酸 (Na2CO3) 溶解度显著增加.
- 融化流体不混合性消失,导致一个连续的过渡.
- 这种过渡发生在深层地的条件下,从Na2CO3融化到热水盐水.
结论:
- 深层碳酸盐中的连续融化流体过渡将REEs集中在盐水融化中,形成矿石体.
- 在浅层系统中,REEs更喜欢碳酸盐性岩石而不是盐水,在碎片化有限的岩石中分散.
- 这项研究提供了关于碳酸盐复合体内的REE沉积物的起源的见解.
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