Abolishment of Niger (LL6) as a distinct fall.

Christophe Michel-Levy (1969) declared two ordinary chondrites Niger II and Niger III, which the Meteoritical Bulletin call Niger (LL6) and Niger (L6). Little material (3.3 g and 2.72 g) remained, as a result of a destructive analysis before their meteoritic nature came to be seriously considered at the Service des Mines National (SODEMI) of Côte d’Ivoire. One of them is reportedly associated to an observed fall near the village of Koutiaran (Mirria district) on August 1, 1967, but Christophe Michel-Levy (1969) was unsure which. The Meteoritical Bulletin Database has, until now, attributed that fall date both stones, under separate names. Dr Christophe also donated a 104.3 g undeclared meteorite to MNHNP, entered as “Koutiaran” in its catalog (no. 3471), again assigned the same fall date, and indicated to be “maybe Niger.” It is briefly mentioned in Christophe Michel-Levy and Ragot (1971) as an “hypersthene chondrite” (consistent with its newly measured logX = 4.80). Suspicion was thus aroused that the three meteorites may be actually paired.

Macroscopic and microscopic examination of sections of all three samples shows similar type 6 petrographies, with no apparent weathering. Electron microprobe analyses yielded (± 1 SD): Niger II ("LL6"), inv. 3472, Fa_25.1±0.2 (N=4), Fs_21.0±0.4 (N=3); Niger III ("L6"), Inv. 3473, Fa_25.2±0.5 (N=6) Fs_20.9±0.2 (N=3); "Koutiaran," Inv. 3471, Fa_25.3±0.1 (N=3), Fs_21.6±0.5 (N=3). These are indistinguishable results, consistent with an L6 classification for all stones. The Fa₃₀ composition, which Christophe Michel-Levy (1969) obtained from X-ray diffraction patterns for Niger II, were likely in error. The three specimens are evidently paired L6 chondrites. The name "Niger LL6" is hereby abolished, and the mass of all three (114.2 g) are henceforth considered part of Niger (L6).