The Redfields Meteorite—A Unique Iron from Western Australia

J. R. De Laeter1, G. J. H. McCall1 and S. J. B. Reed
Department of Physics, Western Australian Institute of Technology, Bentley, W.A. 6102, Australia
Research and Exploration Management Pty. Ltd., 470 Collins St., Melbourne, Victoria 3000, Australia
Department of Geophysics and Geochemistry, Australian National University, Canberra, A.C.T. 2600, Australia
1Honorary Associate, Western Australian Museum, Perth.

Summary: A metallic mass brought to the Western Australian Museum from the Wongan Hills district N.W. of Perth has been identified as an iron meteorite of unique type. It has graphite inclusions about I mm across distributed throughout the metal giving a ‘raisin bread’ appearance. Its nickel content (6·65 %) is comparable with that of coarse octahedrites but the kamacite grain structure is anomalous. Its gallium, germanium, and nickel contents place it close to, but outside, Wasson's chemical group IIb. Taenite is absent and troilite is rare. Neumann bands in the kamacite are distorted and the kamacite has flowed around large schreibersite inclusions. The latter have an exceptionally low nickel content (7·0 %) and probably formed at an unusually high temperature. The kamacite contains more phosphorus than normal iron meteorites, and small schreibersite grains in the kamacite are relatively nickel-poor (22 %). The unusual structure of this iron is thought to be due to one or more of the factors high carbon, high phosphorus, and relatively rapid cooling.

Mineralogical Magazine; March 1973 v. 39; no. 301; p. 30-35; DOI: 10.1180/minmag.1973.039.301.04
© 1973, The Mineralogical Society
Mineralogical Society (