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Compositional layering in Io driven by magmatic segregation and volcanism

August 28, 2020

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 analyse 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.

Publication Year 2020
Title Compositional layering in Io driven by magmatic segregation and volcanism
DOI 10.1029/2020JE006604
Authors Dan C Spencer, Richard F. Katz, Ian J. Hewitt, David A. May, Laszlo P. Kestay
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Geophysical Research
Index ID 70213196
Record Source USGS Publications Warehouse
USGS Organization Astrogeology Science Center