Vaca Muerta End Piece

A RARE STONY-IRON METEORITE FROM HIGH IN THE ATACAMA DESERT

Vaca Muerta fell to Earth approximately 3,500 years ago, a dating made possible through Carbon-14 analysis. It would have been bombarded with cosmic rays as it drifted through space, but once it fell to Earth and was protected by our atmosphere, the carbon-14 atoms begin their slow and steady decay. As a result, measuring the proportion of carbon-12 to carbon-14 atoms can give us the approximate date that this and other meteorites landed.

The original pieces of Vaca Muerta were discovered in the middle of the 19^th century by miners who saw the gleaming iron-nickel metal in the meteorite and believed they had found the beginnings of a silver vein. However, the site was quickly forgotten, only to be rediscovered in 1985 by Edmundo Martinez, a young geology student from the Universidad del Norte in Antofagasta. Indeed, nearby to the rediscovered find were mining tools, cooking utensils, cans, nails, and a coin dated from 1871, clearly the belongings of the original miners who knew of the site.

Vaca Muerta is a mesosiderite, and is therefore a stony-iron meteorite alongside the pallasites. Like the pallasites, mesosiderates are extremely rare, with only .45% of meteorites — or about 1 in 220 — being classified as mesosiderites. However, whereas pallasites emerge from the mantle-core boundary of an asteroid, mesosiderites originate from violent collisions between stony and iron meteorites, creating incredibly unique looks to each one. This meteorite end piece is special because it has a large nickel inclusion that has since oxidized and turned green, alongside additional nickel on the uncut side.

REFERENCES:

Meteoritical Bulletin Entry for Vaca Muerta