NORTHWEST AFRICA 3127


LL3.10, metal-poor
(possible ungrouped ordinary chondrite)
standby for nwa 3127 photo
Purchased October 2002
no coordinates recorded

A single stone weighing 487 g was found in the Sahara Desert and sold to A. and G. Hupé in Safsaf, Morocco in October 2002. This meteorite is very weakly shocked to stage S2 and heavily weathered to grade W3. Through analyses conducted at Northern Arizona University (T. Bunch and J. Wittke) and the U.S. Geological Survey in Reston, Virginia (J. Grossman), it was determined that NWA 3127 is a polymict chondrite consisting of an LL3.1 host with LL4 and LL5 xenoliths.

Studies of the compositional, textural, and other petrographic features of chondrules in NWA 3127 revealed that it had close similarities to those of the LL3.0 Semarkona and the LL3.1 NWA 1756 chondrites. As a sensitive indicator of petrologic subtype (Grossman, 2004; Grossman and Bearley, 2005), the olivine chromite contents of NWA 3127 were measured and found to have values (ave. 0.38 wt%) consistent with an LL3.10 classification. After further analyses conducted by Grossman and Brearley (2007), a reclassification was made for NWA 3127 providing a refined subtype of LL3.10. Northwest Africa 3127 has a very low metal abundance, which was found to be a primary feature rather than an effect of terrestrial weathering.

After the publication of NWA 3127 in MetBull 89 as an LL3.1 chondrite, D. Rumble, III et al. (2007) conducted a survey of the O-isotopic composition of this meteorite and several other metal-poor, ungrouped chondrites in the NWA-series: 960 [ung], 2040 [LL], 2041 [L], 3114 [L], 3127 [LL], 3157 [L], 4294 [LL], 4298 [LL], 4486 [L], and 4531 [LL]. It is demonstrated in the oxygen three-isotope diagram below that these meteorites plot far away from the trend lines for the H, L, and LL ordinary chondrite groups, and they probably represent several previously unrecognized parent asteroids (Irving et al., 2014, #5332). See further details about this "supra-TFL" grouping of meteorites on the HaH 180 page.

standby for metal-poor diagram
Diagram credit: Rumble, III et al., 38th LPSC, #2230 (2007)

Additionally, the ungrouped chondrites NWA 4486 and NWA 5717, as well as the ungrouped achondrites NWA 7835 (Irving et al., 2014, #5332) and NWA 10769 (Moggi Cecchi et al., 2016, #2696), might be related to this metal-poor group of meteorites. The specimen of NWA 3127 shown above is a 1.1 g partial slice.