Experimental Studies on Melting (Mg, Fe)O Ferropericlase

地球和我们自己以及其他太阳系中的其他行星的起源和随后的演化由几个因素决定，包括原始成分和组成阶段的熔融行为。然而，对地幔融化温度的估计仍然存在争议和难以捉摸。地幔的体积占地球体积的四分之三以上，质量占地球质量的近三分之二。地幔熔融和凝固的条件对了解成分不均质性特别重要，这种不均质性制约着深层结构和混合，对于推断地球的热化学演化--从行星吸积和岩浆海洋到大陆增长、海洋和大气的形成以及核幔边界的当前状态--至关重要。地幔中最丰富的矿物之一--镁铁方镁石(Mg，Fe)O在高压下的熔融行为将检验有关地球形成的假说，并阐明深部地幔的地球化学。在大于~1200公里的压力下进行的实验表明，随着压力的增加，理想的固溶体行为变得更像共晶。这些实验将通过绘制样品材料的温度、成分和纹理的二维图谱进行研究，这些样品放置在由激光加热的钻石顶压室产生的地球早期地幔的极高压力和高温条件下，以确定发生熔化的条件及其随后对熔体和周围区域的成分和形态的影响。此外，这项实验研究将通过估计核-地幔边界的温度来帮助限制地球当前的温度。

The origin and subsequent evolution of the Earth and other planets in our own and other solar systems is dictated by several factors including original composition and the melt behavior of the constituent phases. However, estimates of the melting temperature of Earth's mantle, which comprises more than three-quarters of the Earth's volume and nearly two-thirds of its mass, remain controversial and elusive. The conditions at which the mantle melts and solidifies is especially important for understanding compositional heterogeneity, which constrains deep structure and mixing and is crucial for inferring the thermo-chemical evolution of the Earth, from planetary accretion and the magma ocean, to continental growth, the formation of the oceans and atmosphere, and the current state of the core-mantle boundary. The melt behavior of one of the most abundant minerals in the mantle, ferropericlase (Mg, Fe)O, at high pressures will test hypotheses on Earth's formation and elucidate the geochemistry of the deep mantle. Experiments conducted at pressures corresponding to depths greater than ~1200 km suggests that an ideal solid solution behavior becomes more eutectic-like with increasing pressure. The experiments will be studied by 2-dimensional mapping of temperature, composition and texture of sample materials placed under the extreme high-pressure, high-temperature conditions of the Earth's early mantle as produced by a laser-heated diamond-anvil cell, in order to identify the conditions at which melting occurs and its subsequent influence on the composition and morphology of the molten and surrounding regions. Additionally, this experimental investigation will help constrain current temperatures of the Earth by estimating the temperatures at the core-mantle boundary.