Thermal history of mesosiderites revisited

The results of a fission track study of uranium-rich merrillite crystals in a number of mesosiderites are clearly incompatible with cooling rates as low as ~ 0.1°C/Myr which have previously been inferred for these meteorites. Classical metallographic techniques thus appear to give erroneous results when applied to this type of meteorites. There appears to be no reason to advocate exotic scenarios to explain the thermal history of mesosiderites.