Mesosiderites are among the
strangest of all meteorites. They are a breccia of an approximately equal mixture of
silicates and metal that is indicative of multiple and repeated
impacts.
The silicate material is
somewhat similar to the eucrite material
found in howardites, but has chemical differences that suggest additional
mixing with other types of rock. The metals found in mesosiderites are very
uniform, in contrast to the range of metal compositions found in iron
meteorites. This implies that the metal in mesosiderites has a different origin
than the irons.
Lowicz, Poland,
mesosiderite.
Mesosiderites are considered
the "dumping ground" of meteorites as they appear to be a surface
regolith that has been stirred up and fused
by repeated impacts. Some mesos have recrystallized indicating they may have
been deeply buried and somehow reheated at one point in their history. The
mesosiderite, Vaca Muerta, Chile is an
example of the type.
