34 
THE CRANBOURNE METEORITES 
changes to colloidal ferric oxide, which dries up to form pustules 
of limonite in the course of a few weeks. Sometimes a little nickel 
chloride develops in this way, as was noted with the Pakenham 
meteorite (Edwards and Baker, 1941). 
It is noteworthy that the Cranbourne No. 2 iron, which does 
not show this tendency to rapid oxidation and scaling, is similar 
in chemical composition to the irons that do oxidize ; but, so far 
as has been noticed, it has not exuded more than a few droplets 
of iron chloride. This mass shows flight markings, and is there- 
fore part of the exterior of the original large meteorite of which 
the several masses described herein are portions. 
Farrington (1901, p. 402) has suggested that gases in meteorites 
were partly chemically united and partly probably held in inter- 
molecular spaces. If the chlorine (or chloride content) is a 
primaiy constituent of the Cranbourne meteorites, then presum- 
ably it was expelled (or oxidized) in the surface layers of the 
original meteorite at the temperature attained during flight 
through the atmosphere and driven under pressure into the interior 
of the mass where it was retained in the interspaces between the 
kamacite lamellae. 
Another possibility is that the chlorine (or chlorides) was 
introduced into the meteorites as they lay, almost completely 
buried, in the ground. The area in which they occurred is distinctly 
swampy during some periods of the year, as evidenced by the 
records of the Victorian Mines Department, and the subsoil is 
saline, carrying as much as 0T per cent, of sodium chloride 
(Holmes, Leeper and Nicolls, 1940) . Many of the meteorite masses 
lay in the subsoil for not less than 70 years, and chlorides in the 
surface waters might have penetrated the iron along cracks and 
grain boundaries. 
Acknowledgments 
The authors are indebted to the Director of the Victorian Geological Survey 
Department, Mr. AV. Baragwanath, for the photographs of Cranbourne Nos. 5 
and 8 meteorites, for permission to use information from original correspondence 
in the Victorian Mines Department’s files relating to the occurrence and history 
of Cranbourne Nos. 4, 5, 7 and 8 irons, and for additional data concerning the 
meteoritic masses. Our thanks are also due to the Director of the National 
Museum, Melbourne, Mr. D. J. Mahony, for granting us access to Cranbourne 
No. 4 meteorite, and for allowing us to use material from this mass for chemical 
and mineralogical investigations. Mr. G. Ampt and Mr. G. Leeper, of the 
Melbourne University Chemistry Department, kindly offered suggestions leading 
to the ideas relating to the probable origin of the chlorides in the meteoritic 
masses. AVe are grateful to Mr. A. AVilcock, of the Melbourne University Metal- 
lurgy Department, for cutting and' shaping samples of Cranbourne No. 7 
meteorite ; to the personnel of the Victorian Mines Department Drill Store for 
