New England Meteoritical Services


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.

New England Meteoritical Services