Nearly carbon‐saturated magma oceans in planetary embryos during core formation
Nearly carbon‐saturated magma oceans in planetary embryos during core formation
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核心形成过程中行星胚胎中接近碳饱和的岩浆海洋
DOI：
10.1029/2021gl092389
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发表时间：
2021
影响因子：
5.2
通讯作者：
Irifune Tetsuo
中科院分区：
文献类型：
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作者：
Kuwahara Hideharu;Itoh Shoichi;Suzumura Akimasa;Nakada Ryoichi;Irifune Tetsuo
由于其强烈的亲铁行为，在地核形成后的行星地幔被认为在碳中高度耗尽。然而，月球和陆地地幔中的碳含量比实验预测的要高得多；因此，陆地地幔中的碳含量是如何确定的是令人困惑和知之甚少的。在这里，我们进行了高压实验，在2gpa和1923 K下，在含0.2 wt% C的体系中，碳的金属硅酸盐分配接近于顽辉石球粒陨石，并表明由球粒材料组成的岩浆海洋即使在金属饱和的情况下也几乎饱和碳。硅酸盐熔体中碳的溶解度与月球和地球地幔中的碳含量之间的一致性也支持了在岩心形成过程中一个接近碳饱和的岩浆海洋，并表明地球地幔中的碳含量可能在主要吸积阶段就已经确定了。
A planetary mantle after core formation has been thought to be highly depleted in carbon due to its strong siderophile behavior. However, the carbon contents in lunar and terrestrial mantles are much greater than experimental predictions; thus, how the carbon contents in terrestrial mantles were established is puzzling and poorly understood. Here, we present high‐pressure experiments on the metal‐silicate partitioning of carbon at 2 GPa and 1923 K in a system containing 0.2 wt% C, which is close to that in enstatite chondrites, and show that a magma ocean made of chondritic materials is nearly saturated with carbon even under metal saturation. The consistency between the solubility of carbon in silicate melts and the carbon contents in lunar and terrestrial mantles also supports a nearly carbon‐saturated magma ocean during core formation and suggests that carbon contents in terrestrial mantles may have been established during the main accretion phase.