Northwest Africa 8614 meteorite (NWA 8614), Northwest Africa Meteoritesi

Regional Level Types
Northwest Africa 8614 meteorite (NWA 8614)	Meteorite Fall Location
Northwest Africa Meteorites	Group of Meteorite Fall Locations

Northwest Africa 8614 is classified as a winonaite on the basis of oxygen isotope ratios, mineralogy, and highly reduced chemistry. Unlike other winonaites, it contains numerous and readily apparent chondrules, with over a dozen chondrules apparent in two small thin sections. The large number of chondrules sets apart this meteorite from other winonaites.

Owing to the abundance of chondrules, NWA 8614 may be one of the least heated winonaites and therefore may provide clues to the chondritic protolith of the winonaite parent body. Overall textures are similar to those found in type 6 chondrites that escaped significant melting.

Despite similar geothermometer temperatures for various mineral pairs, NWA 8614 apparently did not attain Fe-Mg equilibrium between olivine and pyroxene. Like other winonaites, NWA 8614 has olivine compositions that are too magnesian for equilibrium relative to low-Ca pyroxene. Among winonaites as a whole, there is no evidence for a curved trend between Fa and Fs compositions as would be expected for FeO-reduction during metamorphism [Benedix, et al 1998], nor for mineral compositions that correlate with geothermometry temperatures. This argues against a single metamorphic FeO reduction trend from a common chondritic precursor. Instead, protoliths for different winonaites may have varied slightly in composition.

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