The compositional evolution of volcanic bodies like Io is not well understood. Magmatic segregation and volcanic eruptions transport tidal heat from Io's interior to its surface. Several observed eruptions appear to be extremely high temperature (≥1600 K), suggesting either very high degrees of melting, refractory source regions, or intensive viscous heating on ascent. To address this ambiguity, we develop a model that couples crust and mantle dynamics to a simple compositional system. We analyze the model to investigate chemical structure and evolution. We demonstrate that magmatic segregation and volcanic eruptions lead to stratification of the mantle, the extent of which depends on how easily high temperature melts from the more refractory lower mantle can migrate upwards. We propose that Io's highest temperature eruptions originate from this lower mantle region and that such eruptions act to limit the degree of compositional stratification.

中文翻译：

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岩浆偏析和火山作用驱动的Io中的成分分层

诸如Io之类的火山体的成分演化尚不十分清楚。岩浆分离和火山喷发将潮汐热从艾奥内部传递到其表面。观察到的几次喷发似乎是极高的温度（≥1600 K），表明要么很高的熔化度，难熔源区域，要么上升时剧烈加热。为了解决这种歧义，我们开发了一个模型，将地壳和地幔动力学耦合到一个简单的组成系统。我们分析该模型以调查化学结构和演化。我们证明了岩浆的分离和火山喷发导致地幔分层，其程度取决于来自难熔的较低地幔的高温融化向上迁移的难易程度。我们建议艾奥的最高温度喷发源于这个较低的地幔区域，并且这种喷发的作用是限制成分分层的程度。