Lewis Cliff 87232 meteorite, Lewis Cliff, Buckley Island quadrangle, Eastern Antarctica, Antarcticai

Regional Level Types
Lewis Cliff 87232 meteorite	Meteorite Fall Location
Lewis Cliff	Cliff
Buckley Island quadrangle	Quadrangle
Eastern Antarctica	Region
Antarctica	Continent

K Chondrite (K3)
Find, 1987; 23.1 g

LEW 87232 was recovered as a small rounded stone with small patches of its fusion crust still remaining on one side. It appeared to be even more weathered at its center than at its exterior. Chondrules, fragments, and rounded metal regions are dispersed in the fine-grained, yellowish matrix which accounts for ~70 vol% of the meteorite. Chondrules (ave. diameter < 0.5 mm) are mostly porphyritic pyroxenes (PP), but olivine may be poikilitically enclosed in some chondrules and a few others are olivine-rich. As is true of all members of the small K chondrite grouplet, both the olivine (Fo98.8) and pyroxene (enstatite, clinoenstatite, and Ca-rich pyroxene) are extremely Mg-rich. Fe-Ni metal spheroids — referred to as 'chondrules' by Weisberg — may have originally accounted for ~10-20% of the meteorite. Small amounts of apatite and schreibersite are associated with the Fe-Ni metal. Opaques include the kamacite and taenite of the metal and troilite. Very minor amounts of spinel/pyroxene-rich material in tiny inclusions are also reported.

Lewis Cliff 87232 is one of the only four K (Kakangari-like) Chondrites known as of mid 2015. The prototype, Kakangari, is itself quite small (~340 g), but it still accounts for ~80% of the ~420 total K chondrite mass. Thus the three small and weathered finds present some difficult issues for precise classification. However, LEW 87232 olivine is seemingly less variable [Fa 0.6-2.0], but still incompletely equilibrated and its chondrules more Mg-rich than Kakangari (K3) so, it is listed here as petrographic type K3 along with Kakangari and Lea County 002. The more recent 2014 find, NWA 10085, has been listed as petrologic type K4.

Other Regions, Features and Areas containing this locality

References