Low Core-Mantle Boundary Temperature Inferred from the Solidus of Pyrolite
Low Core-Mantle Boundary Temperature Inferred from the Solidus of Pyrolite
复制标题
DOI：
10.1126/science.1248186
复制
发表时间：
2014-01-31
期刊：
影响因子：
56.9
通讯作者：
Ueno, Yuichiro
中科院分区：
文献类型：
--
作者：
Nomura, Ryuichi;Hirose, Kei;Ueno, Yuichiro
地幔的熔融温度是制约地幔和地核热结构的关键因素。通过高压实验和三维X射线显微断层成像，我们表明，在地幔和外核之间的边界附近的压力下，原始（热解）地幔的固相线温度低至3570 +/- 200开尔文。由于最低的地幔不是全球熔融的，这提供了一个上限的温度在核幔边界（T-CMB）。如此显著低的T-CMB意味着后钙钛矿相存在于最低地幔的广泛区域中。低T-CMB还要求外芯的熔化温度被诸如氢的杂质大大降低。
The melting temperature of Earth's mantle provides key constraints on the thermal structures of both the mantle and the core. Through high-pressure experiments and three-dimensional x-ray microtomographic imaging, we showed that the solidus temperature of a primitive (pyrolitic) mantle is as low as 3570 +/- 200 kelvin at pressures expected near the boundary between the mantle and the outer core. Because the lowermost mantle is not globally molten, this provides an upper bound of the temperature at the core-mantle boundary (T-CMB). Such remarkably low T-CMB implies that the post-perovskite phase is present in wide areas of the lowermost mantle. The low T-CMB also requires that the melting temperature of the outer core is depressed largely by impurities such as hydrogen.