NORTHWEST AFRICA 1242


Mesosiderite, group A2
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Found 1985
no coordinates recorded

Two fragments with a combined weight of ~7 kg were found near the village of Gillio, Libya by an oil worker. The masses were utilized as bookends until they were purchased from the worker's daughter by meteorite dealer A. Lang in 1998. A sample was submitted to Rutgers University (R. Hewins) for analysis and classification, and the name Sahara 85001 was chosen to be most appropriate given the lack of an exact find location. However, results were not forthcoming, and four years later an additional sample was submitted for classification to Northern Arizona University (T. Bunch). By this time in 2002, the NWA-series had been established by the Meteorite Nomenclature Committee of the Meteoritical Society, and the name NWA 1242 was assigned to this mesosiderite. Since the find location of this meteorite is in Libya it was officially included in the NWA-series. In the interim a couple of kilos of this meteorite were sold under the name Sahara 85001, and this name is now a synonym for the official name NWA 1242. Northwest Africa 1242 was classified at Northern Arizona University as a member of the A2 metamorphic group. (see the Bondoc page for further information about the Floran (1978) and Hewins (1984) classification schemes).

Northwest Africa 1242 contains scattered, cm-sized, metal nodules (see photo below), together with lithic clasts consisting of Ca-rich pyroxene, anorthitic plagioclase, pyrrhotite, chromite, and FeNi-metal. This unweathered mesosiderite (W0) is shocked to stage S1. The specimen shown above is an 11.67 g partial slice. The top photo below is a close-up image of a large, etched metal nodule, while the bottom photo shows the main mass of NWA 1242.

standby for northwest africa 1242 photo

standby for northwest africa 1242 photo
Photos courtesy of Alan Lang—R. A. Langheinrich Meteorites