NO. 12 ORU.M MOUNTAINS METEORITE — HENDERSON AND PERRY 3 



surfaces within the depression a slightly thicker film of oxide has 

 accumulated. The side walls of these depressions are in most cases 

 spherical in form, and frcciiiently the openings have less of a diameter 

 than the width of the cavity wiien measured about halfway down 

 toward the bottom. 



That portion of the Drum Mountains specimen that was buried 

 in the ground has a very different appearance from the rest of the 

 meteorite. The oxide coating is more scaly and appears alx)ut like 

 the rust on a weathered artificial iron. The oxide coating over the 



Table i. — Approximate ditiicnsioiis of the cai'itics in Drum Mountains 



meteorite 



Dianicter/dcpth 

 0.83 



0.8 



2.00 

 1.66 



1.25 



0.66 



1.66 

 0.66 



rest of the meteorite is firm, rather smootii, and does not appear to 

 have been so intensively weathered as that on the bottom of the speci- 

 men, perhaps because there the wind-blown material has cut much of 

 the oxide film awa). The shallow depressions or "thumb marks" so 

 characteristic of the upper surface of this specimen are less con- 

 spicuous on the UTider side. 



One large cavity which has a sharp rim around its opening was 

 found to contain many layers of concentric iron-oxide scales : in 

 fact this depression was almost entirely filled with scales when the 

 meteorite was received. This cavity was so located on the specimen, 

 as it stood in the field, that it would not have accumulated water from 

 surface rains. Any moisture that did enter would do so by condensa- 

 tion or by capillary creep, against the metal. It appears that this 

 depression was being deepened and enlarged by corrosion from 

 moisture condensed within it. These concentric scales of iron oxide 

 cut across the internal structure of the meteorite making a rosette of 

 scales. (See pi. i, fig. 2.) 



Unfortunately, the scales from this cavity were cleaned out and 

 mixed into one sample. It would have been desirable to have made 

 some tests upon the composition of the various layers to see how the 



