Vaca Muerta meteorite, Taltal, Antofagasta Province, Antofagasta, Chilei

Regional Level Types
Vaca Muerta meteorite	Meteorite Fall Location
Taltal	Commune
Antofagasta Province	Province
Antofagasta	Region
Chile	Country

Mesosiderite-A1; S1 (Stony-Iron)
Found in 1861. 3.83 tons

The Vaca Muerta meteorite is the most massive of the 216 mesosiderites recovered between 1842 and 2014. It is more than 4 times as massive as the second most massive mesosiderite, Bondoc, an 888.6 kg mass recovered from the Philippines in 1956. Several pieces up to 25 kg in mass were found in the late 19th century. A large strewnfield (11.5 km x 2.1 km) has resulted in a number of additional pieces being recovered after the first few pieces were found. Vaca Muerte is a fairly typical 'mesosiderite' with ~47 wt% Fe-Ni metal, ~40 wt% silicates and ~12-13 wt% troilite according to the summarizing work of Mittlefehldt et al. (1998). Most mesosiderites have a diverse set of silicates and other phases which have apparently undergone some dramatic interactions with invading iron during early solar system epochs. Vaca Muerte might be expected to have even more diversity because its silicate matrix is only partially equilibrated and also because the sheer amount of available mass creates additional diverse micro-environments. And, indeed, olivine, pyroxene, and plagioclase both as individual clasts and in matrix have been frequent objects of study. Accompanying them are a number of additional oxides, opaques, and other phases of interest — and presumably more will be found.

A word of caution. The number of phases produced by terrestrial weathering reported from Vaca Muerte is rather high. Brecciated, sulfide-rich meteorites are particularly vulnerable to attack by air and water. The aragonite, calcite, goethite, limonite, paraotwayite and retgersite listed below are mostly — and quite likely - entirely the products of terrestrial weathering. Hopefully, there are still enclaves of other unusual and perhaps highly reduced phases yet to be uncovered (in addition to the more or less expected Fe-Ni metal, troilite, and schreibersite).

Vaca Muerta is one of the 7 mesosiderites classified as A1 Mesosiderites (relatively plagioclase-rich; unequilibrated matrix). Moderately large pieces of Vaca Muerte are found at a number of museums (15 kg at the Museum d'Histoire Naturelle in Paris, 9 kg in the American Museum of Natural History in New York, 8 kg in the Museum of Natural History in London, etc.) with many smaller pieces being displayed and sold on the Internet in various venues.

Other Regions, Features and Areas containing this locality

References