NORTHWEST AFRICA 13955

A single stone weighing 1760 g was found in the Erg Chech DCA in Algeria by Saharawi hunters. The meteorite was subsequently sold through a dealer in Nouadhibou, Mauritania to Salamu Ali. Samples were sent for analysis and classification to the University of Washington in Seattle (A. Irving), Washington University in St. Louis (P. Carpenter), and the University of New Mexico (oxygen isotopes; K. Ziegler), and NWA 13955 was classified as an ungrouped achondrite with unique characteristics (Irving et al. (2022, MetBull 110).

The meteorite is composed of cumulus grains of low-Ca pyroxene (~70 vol%; orthopyroxene cores mantled with pigeonite), olivine (~20 vol%), and interstitial calcic plagioclase (<10 vol%), along with accessory chromite and FeNi-metal (Irving et al., 2021 #6221). Vesicles or vugs in various sizes are present throughout the stone. An oxygen isotopic analysis conducted at the University of New Mexico (K. Ziegler) shows that NWA 13955 plots near two anomalous eucrites, NWA 8671 and NWA 13355, the Bholghati howardite, and the ungrouped achondrite Al Bir Lahlou 001, some or all of which may represent additional parent bodies. (see diagrams below).

Further information about the anomalous eucrite-like meteorites and their proposed origin from multiple distinct parent bodies can be found on the Pasamonte page. The specimen of NWA 13955 shown above is a 5.46 g partial slice with vesicles and an olivine-rich region across the middle.