在下层地幔条件下,大卫的持久性
Lin Wang1, Nobuyoshi Miyajima1, Fei Wang1
1Bayerisches Geoinstitut, University of Bayreuth, Bayreuth, Germany.
概括
达维玛,一个关键的酸盐矿,在地球下层地幔中稳定. 它的存在,与可溶性挑战相反,影响地幔动态,并可能解释大型低剪切波速度省份.
科学领域:
- 地质物理学 地质物理学
- 矿物物理 矿物物理
- 地球科学 地球科学 地球科学
背景情况:
- 下层地幔的矿物学是地球结构和动态的关键.
- 人们认为达维玛 (酸盐矿) 与布里格曼石共存,这对于理解下层地幔演变至关重要.
- 在布里格曼石中高溶解度挑战了达维玛的存在.
研究的目的:
- 在下层地幔条件下实验性地确定桥矿中的溶性.
- 确定大卫岩石在地球下层地幔中的稳定性和存在.
- 调查大卫岩石稳定性对地幔结构和演化的影响.
主要方法:
- 使用了超高压多杆技术.
- 模拟下层地幔压力,温度和化学成分.
- 在实验条件下分析了桥矿中的溶性.
主要成果:
- 在布里格曼石中显示的溶性不足以在地幔条件下消除达维玛.
- 自形成以来,在下层地幔中确认了大卫岩石的稳定性.
- 在核心-地幔边界确定了潜在的davemaoite丰富的域.
结论:
- 达维玛是地球下层地幔中稳定的矿物.
- 在核心-地幔边界可能存在大卫丰富的域,作为不兼容的元素储库.
- 这些域可能解释了大型低剪波速度的省份和海洋岛屿的玄武岩来源.
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