PAN- 
AMERICAN GEOLOGIST 
/ 
VoL. XXXVII June, 1922 No. 5 
I 
RIGHTFUL DEMESNE OF PETROLOGY ‘ 
By Prof. Charles P. Berkey 
I 
Columbia University 
Petrographers are often so occupied with the task of describ¬ 
ing and classifying so many historically unrelated things that the 
workers who come after the leaders in their science frequently 
entirely miss the true function of their efforts not only in their 
educational but their scientific bearings. In attempt to point out 
what this rightful sphere is it is not so very far wrong to assert 
that Petrology is the science of rocks; but in saying so we do not 
make ourselves entirely clear. To the average student of this 
subject who must judge from what he is taught and from what 
he finds in the texts, petrology appears to be a highly complicated 
lot of methods of descrimination, coupled with still more intricate 
schemes of classification, by means of which he finally finds some 
mystifying name for a very common and innocent looking frag¬ 
ment of rock. This is hardly real petrology. It is hardly beyond 
the most elemental stage. 
After the first steps in a new science are taken it is not suffi¬ 
cient to assume that a long list of strange names, descriptive terms, 
and tabulations of fact can satisfy the demands of an inquiring 
mind. Petrology is just entering upon a more advance stage than 
that mentioned. This is evidenced often in the growing impa- 
1 Abstract of paper read before the Geological Society of America at the Chicago 
meeting. 
353 
