Hello, According to Buchwald, the production of fusion crust does occur in irons, while heat-affected rim zones are present below this fusion crust. Partially quoting from his first volume, in the chapter Shapes and Surface Characteristics, he writes that these fusion crusts differ from those of stones in that iron fusion crusts consist of complex, mixed melts of fully and partially oxidized metal. The oxide melts have solidified and decomposed to wustite-magnetite layers, while the metallic melts have solidified to a multilayer dendritic-cellular zone transformed to fine-grained martensite. These fusion crusts are only sub-mm in depth, with another 10 mm of heat-affected zone, where the temperature didn't rise above 300-400*C. A nice diagram is shown on page 52. I love the photos that are made of the fusion crusts after being coated with ammonium chloride.
David ______________________________________________ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
