312 ANNUAL REPORT SMITHSONIAN INSTITUTION, 193 3 



the MacDonnell Ranges. Pieces of meteoric iron having been sent 

 from there to the University of Adelaide with the statement that 

 they had been found around craterlike depressions, A. R. Alderman 

 at once proceeded to the locality in May 1931, when he was quick to 

 recognize the importance of the discovery.^" Within an area of half 

 a mile square he mapped 13 craters, and around them he collected 

 more than 800 pieces of meteoric iron, together with much iron shale 

 and some black glassy material. At one spot over an area of 6 by 6 

 feet more than a hundred small pieces of iron were picked up. The 

 largest crater is oval in outline, 220 by 120 yards across, and 50 to 60 

 feet deep. The others are approximately circular with diameters 

 ranging from 10 to 80 yards and depths from 3 to 25 feet. 



With their gently sloping outer surfaces the craters are not very 

 conspicuous until one stands on the rim, when the steep inner slopes 

 come into view. The craters are, however, marked out by the growth 

 of mulga trees, acacias, and coarse grass, since they act as collecting 

 pans for rainwater in this arid region (average rainfall, 6 inches 

 per annum). The steep inner walls consist of powdered rock and 

 shattered blocks of sandstone, quartzite, and slate of Ordovician age. 

 Only at one spot in the walls were the rocks seen to be api^arently 

 in situ and with the same dip as in the surrounding country. A 

 feature that may perhaps be of some significance was noted by Mr. 

 Alderman around two or three of the craters, but best seen around 

 crater no. 3, which is 45 yards in diameter. Here, radiating from 

 the rim, are five or six low ridges of sandstone, only a few inches 

 in height and varying considerably in length, the average length 

 being about 30 yards. It is suggested that these may have resulted 

 by the percussion of the meteorite. Only two pieces of iron (one 

 of 13 pounds) were found inside one of the craters, and these on the 

 surface just inside the rim. A boring in the floor of crater no. 5 

 (25 yards diameter) passed through 8 feet of fine silt down to rock 

 fragments, but no iron was found. 



A large amount of material, together with much valuable infor- 

 mation about the Henburj'^ craters, has been sent to the British Mu- 

 seum by R. Bedford, of the Kyancutta Museum, in South Australia, 

 who visited the locality in June 1931 and May 1932*. This includes 

 642 pieces of the iron with a total weight of 891 pounds (405 kilos) . 

 The largest pieces weigh 292, iTO^/o, and 120 pounds, but the majority 

 are small and curiously twisted and curved. A selection of this 

 material is on exhibition in the Natural History Museum at South 

 Kensington. Most interesting is a group of four irons with a total 



i*A preliminary illustrated account was published in the Adelaide Chronicle of July 16, 

 1931, and a more detailed account in March 1932 (op. cit.). A few furtiior details 

 respecting the craters are given by A. R. Alderman, The Henbury (Central Australia) 

 meteoric iron. Rec. South Australia Museum, vol. 4, pp. 555-563, 9 figs., 1932 



