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24 TRANSACTIONS OF THE 
A SHORT COMMENT ON BULLETIN 371 OF THE 
U. S. GEOLOGICAL SURVEY. | 
By J. B. FORRESTER. 
Having spent several years in close contact with the 
Book Cliffs Coal Field, and having studied the geology 
of that region through actual surveys, I believe that a 
short comment on Mr. Richardson’s paper may not be out 
of place. 
It is by a comparison of ideas advanced by different 
observers that the science of Geology has attained it present 
prominence, and mistakes as well as truths have given it 
a great impetus. 
It will be unnecessary to go into the history of the 
literature concerning the Laramie and the Mesa Verde 
Formations, but we shall confine ourselves to the paper 
under consideration. 
Since 1903 it has been my privilege to study and 
collect fossils in the Laramie, or Coal Bearing Series, of 
Eastern Utah; also those of southwestern Colorado, and 
the Mesa Verde in the same region. I have also run 
outcrop surveys from Sunnyside to the Beckwith Plateau 
and from Castlegate to Huntington Canyon. These, 
together with several geological profiles, cover farily 
well this portion of Utah. 
I shall give a description of what has, until lately, 
been known as the Laramie formation. At Castlegate the 
Laramie consists of some 3000 feet of alternating sand- 
stones and shales. The strata are thick and represent 
long periods of submergence. The conditions of deposition 
have been very uniform. However, the Castlegate sand- 
stone which lies at the top of the coal bearing series, is 
materially different from the other sandstones in this 
formation. The lower sandstones weather into a honey- 
comb appearance. This is due to wind erosion. There 
are no joints, so all edges are rounded. Immediately 
under these sandstones, of which there are two, are shales, 
easily weathered and eroded. Thus the sandstones are 
undermined, the overhanging ledge breaks off and the 
