106 The Interior of the Earth. [Sess. 



fessor Steenstrup led him to the conclusion that the masses of 

 iron were not of meteoric origin at all. This part of Western 

 Greenland, in Miocene times, was the focus of very intense 

 volcanic activity, and near the spot where the iron masses 

 occur there are found numerous basaltic dykes, which, when 

 closely examined, were found to be full of particles of metallic 

 iron. The matter has been carefully gone into by other 

 authorities, and the conclusion arrived at is that the large 

 iron masses of Ovifak, as well as the particles diffused through 

 the basalts, are of terrestrial origin, and have been brought up 

 from the interior of the earth by volcanic agency. It is 

 supposed that by the weathering away of the basalts the large 

 blocks of iron have been liberated from their matrix, and were 

 left exposed in the position where they are found. It is 

 probable that, just as we find in many basaltic lavas nodules 

 of ultra -basic materials similar to the stony portion of 

 meteorites, so in these basalts of Ovifak we have masses of 

 iron alloyed with nickel, &c, similar to the metallic portions 

 of meteorites. Both the stony and the metallic enclosures 

 in the basalts are in all likelihood derived from deeper 

 portions of the earth's crust. 



Other facts go to support this conclusion. Professor 

 Andrews has shown that certain basalts in our own islands 

 contain microscopic particles of iron. Further evidence is 

 furnished by the occurrence of mineral veins proper. In 

 these veins, which are supposed to communicate with the 

 interior by deep fissures, the native metals and their alloys 

 are found, also their compounds with sulphur, chlorine, phos- 

 phorus, &c; but their oxides, except as products of subsequent 

 alteration, occur far less frequently than in the earth's crust 

 generally. 



Putting all these scraps of evidence together, and bearing 

 in mind the demonstrated fact that the materials composing 

 the interior are of much greater density than those at the 

 surface or composing the higher portion of the crust, we may 

 fairly conclude that those materials which we see at the 

 surface for the most part combined with oxygen, are at very 

 great depths found in their free or uncombined state, and 

 that among them metallic substances, especially iron, play an 

 important part. To conclude with a rough illustration, our 



