88 



Run Mountain stood, as I found by compass, N. N. E. by E. from tbe Sweet 

 Springs ; and Peter's Mountain, of which I could get a peep through the trees, 

 bore east of the place where I stood. 



" Here was an extraordinary phenomenon ! an immense deposit of travertin, 

 lying three hundred and fifty feet above the level of the spring from which it 

 probably was derived. It seems to be susceptible of no other explanation than that 

 the level of the valley was, at some remote period, much higher than it is now, 

 and that the springs were, at least, at this level. The Snake Run Mountain is a 

 large limestone outlier from Peter's Mountain, such as are constantly found in the 

 valleys. Before these were scooped out by the retiring currents, it is probable 

 that the whole surface of this now deeply-sulcated region was continuous, and that 

 the springs issued from the bottom of the ocean. When the valleys were swept 

 out, these knobs, hills, and spurs, being hard, compact, transition limestone, re- 

 sisted, and were left ; whilst the conglomerates, shales, and sandstones, were car- 

 ried away : since that period the softer parts of the formations, occupying that 

 part of the valley where the springs now are, have been gradually worn down, and 

 a new direction given to the stream ; whilst the old travertin remains a monument 

 of the ancient level, and one of the strong geological proofs of the process of 

 denudation." 



A considerable portion of the communications now under consideration relate 

 to subjects more or less connected with the mineral resources of some parts of the 

 United States, and which, though of the highest importance, naturally possess a 

 more local interest than other parts of the volume. The contributions relating 

 to organic remains contain some new and valuable information ; but the limits of 

 our present article will not admit of extending our analysis to them, and we must 

 therefore refer our readers for points connected with their history to the work 

 itself. 



There is certainly one subject upon which we cannot help expressing our 

 regret, and that is, that the present volume should be so destitute of information 

 upon the tertiary geology of America. With the exception of a short notice, by 

 Mr. Conrad, upon a portion of the Atlantic tertiary region, we find no allusion 

 whatever to the supra-cretaceous deposits, which are so largely developed in some 

 parts of the United States. The important results which have attended the exa- 

 mination of the beds above the chalk in England and the adjoining continent ; the 

 wide field which has been opened for theoretical inquiry into the causes of pheno- 

 mena which are there presented to us ; and the connection existing between the 

 newest rocks of this period and those deposits which are accumulating from the 

 operation of agents now in activity, give a degree of interest to facts bearing upon 

 the history of that epoch which does not attach itself to any other department of 

 geological investigation. 



We are not, it is true, entirely without sources of information upon the ter- 



