Chinguetti meteorite, Chinguetti, Adrar Region, Mauritaniai

Regional Level Types
Chinguetti meteorite	Meteorite Fall Location
Chinguetti	Department
Adrar Region	Region
Mauritania	Country

Stony-iron, Mesosiderite
Find, 1920; 4.05 kg

Reports of an enormous mass circulated, but only a single mass was ever recovered. A few suggestive droplets of black fused silica were also reported to have been found at the base of a large sandstone hillock where the mass was found. The mass — a flat parallelepiped with a 16x9.5 cm face — consists primarily of Fe-Ni metal (~80 wt%) with a multitude of tiny stone inclusions. A few larger silicate fragments (≤4 cm) are also found. A 1982 modal analysis gave the following (volumetric) breakdown: Pyroxene (42%), Kamacite (39%), Troilite (14%), Plagioclase (3%), Merrillite (<2%) & Tridymite (~0.5%). Kamacite dominates the pervasive Widmanstätten network and envelops the silicates ['swathing' kamacite]. Interstitial troilite is concentrated along metal-silicate joins. Minor amounts of magnesian olivine (Fo75), often surrounded by Fe-enriched coronas, are also present. The silicates, both large and small, are irregularly distributed. A few minor and trace phases have been identified as well.

A cosmic ray age of 66±7 Ma and terrestrial exposure age of 18±1 ka suggest that Chinguetti (1) may have been part of a major mesosiderite collisional break-up 60-70 million years ago and (2) that the radius of the preterrestrial meteoroid was ≤ 80 cm just prior to its impact.

Chinguetti has been classified as a Mesosiderites-B1 (moderate plagioclase abundance; unmetamorphosed, fine-grained matrix). Chinguetti is one of 4 Mesosiderite in the mesosiderite B1 subgroup. [Only a relatively small number (~40) of mesosiderites have been fully classified.] The main mass (3.9 kg) is with the Muséum National d'Histoire Naturelle (Paris). A smaller mass (380 g) is at U.S. National Museum in Washington.

Those who can read French may be interested in the book by Monod & Zanda (1992).

Other Databases

Wikipedia:	https://en.wikipedia.org/wiki/Chinguetti_meteorite
Wikidata ID:	Q5101045

Other Regions, Features and Areas containing this locality

References