English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Open

Presents the pdf analysis as premium feature

PDF Analysis

Insights

Presents the summarisation as premium feature

Summarisation

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Much of the Earth was built by high-energy impacts of planetesimals andembryos, many of these impactors already differentiated, with metallic cores oftheir own. Geochemical data provide critical information on the timing ofaccretion and the prevailing physical conditions, but their interpretationdepends critically on the degree of metal-silicate chemical equilibrationduring core-mantle differentiation, which is poorly constrained. Efficientequilibration requires that the large volumes of iron derived from impactorcores mix with molten silicates down to scales small enough to allow fastmetal-silicate mass transfer. Here we use fluid dynamics experiments to showthat large metal blobs falling in a magma ocean mix with the molten silicatethrough turbulent entrainment, with fragmentation into droplets eventuallyresulting from the entrainment process. In our experiments, fragmentation ofthe dense fluid occurs after falling a distance equal to 3-4 times its initialdiameter, at which point a sizable volume of ambient fluid has already beenentrained and mixed with the dense falling fluid. Contrary to what has usuallybeen assumed, we demonstrate that fragmentation of the metallic phase intodroplets may not be required for efficient equilibration: turbulent mixing, bydrastically increasing the metal-silicate interfacial area, may result in fastequilibration even before fragmentation. Efficient re-equilibration ispredicted for impactors of size small compared to the magma ocean depth. Incontrast, a much smaller re-equilibration degree is predicted in the case oflarge impacts for which the impactor core diameter approaches the magma oceanthickness.

Turbulent metal-silicate mixing, fragmentation, and equilibration in magma oceans