Iron meteorites recrystallize primarily due
to shock events and reheating processes. High-energy impacts in space or
collisions with other celestial bodies generate extreme heat and pressure,
triggering recrystallization. This process disrupts the meteorite’s
original crystal structure, breaking it down and forming smaller grains of key
minerals like kamacite and taenite.
Reheating plays a vital role in recrystallization
and can occur due to proximity to a heat source, such as a molten core, or from
subsequent impacts. During reheating, the metal may partially melt and then
cool slowly, allowing new crystal structures to develop. For instance, forming
uniform 20 µm taenite grains with varied orientations could take roughly
800 years at 600°C or just 1 hour at 1,300°C, according to Goldstein
et al. (2011, Meteoritics & Planetary Science).
Recrystallization can also alter the
meteorite’s chemical composition. As a result, recrystallized iron
meteorites often exhibit a finer, more granular texture compared to their
original form.
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