Lewis Cliff 86018 meteorite, Lewis Cliff, Buckley Island quadrangle, Eastern Antarctica, Antarcticai

Regional Level Types
Lewis Cliff 86018 meteorite	Meteorite Fall Location
Lewis Cliff	Cliff
Buckley Island quadrangle	Quadrangle
Eastern Antarctica	Region
Antarctica	Continent

Ordinary Chondrite, unequilibrated (L3.1; S2; W4)
Find,1986; 502 g

A weathered meteoritic stone (10 x 6 x 6 cm) which still retained ~60% of its fusion crust readily revealed its clastic chondritic texture in spite of a rather weathered interior. Numerous inclusions (one 5 mm in length) are also present. In thin sections distinct chondrules (diameters up to 3 mm), chondrule fragments and irregular aggregates are set in a dark fine-grained matrix. Granular and porphyritic chondrules (PO,POP) are prominent. Average composition of olivine (Fa15) is indicative of the L chondrite group. Distinct chondrules and marked variability of olivine (Fa0.7-32) and pyroxene (Fs2-9) reflect the primitive L3.1 petrologic type designation. Small amounts of troilite and Fe-Ni metal surround some chondrules. Undulose extinction in olivine indicative of moderate shock (level S2). Weathering (grade W4) is seen in iron oxide veinlets and in the rust-colored matrix. Evaporite deposits are found just under the fusion crust.

While the overall LEW 86018 meteorite is roughly characterized in the above paragraph, much of the interest in this very primitive meteorite is in diverse and sometimes tiny inclusions with minerals and isotopic signatures which appear to predate most of the other components. We mention here only a few which have been reported — (1) the diversity of pyroxenes (enstatite [sensu strictu], pigeonite, Ca-poor clinopyroxene), (2) the presence of both Forsterite-rich and Fayalitic olivines, (3) and several Na-rich phases. More diversity is presumably waiting to be discovered or, perhaps, is simply not reported here.

Other Regions, Features and Areas containing this locality

References