THE 



MONTHLY AJVIERICAN JOURNAL 



OF 



GEOLOGY 



AND NATURAL SCIENCE. 



Vol. I. Philadelphia, February, 1832. No. 8. 



GEOLOGY, No. 2.— ON THE ORDER OF SUCCESSION OF THE 

 ROCKS COMPOSING THE CRUST OF THE EARTH. 



The existence of an expansive subterranean power, generated 

 by heat, is so well established by volcanic phenomena, as to ren- 

 der it unnecessary at present to support that opinion, by enter- 

 ing upon any discussions respecting what has been called central 

 heat, founded upon the temperature of the earth, the ocean, or 

 that of the thermal springs found in different parts of the world. 

 With a view to apply that kind of knowledge appropriately, we 

 shall hereafter recur to these branches of our subject. 



We have given on the next page a tabular view of the known 

 rocks of the crust of the earth, comprehending the general geo- 

 logical series of beds, of which that crust is composed ; and lying 

 in that relative order to each other in the series, according to 

 which they are here enumerated. That is to say, that No. 18 

 is never found underlying No. 17, or No. 9 overlying No. 34. 

 We take these examples at random, and mean merely to assert, 

 that the order has not yet, in any part of the world, been found 

 inverted ; and therefore we reasonably conclude, that each of the 

 beds of the series has successively come into the place it is con- 

 stantly found to occupy. If we could assert with equal certainty, 

 that all these beds were to be found thus overlying each other 

 in every part of the world, then we might generalize still fur- 

 ther, and say, that this observed order of the beds, was an effect 

 of causes general to all the parts of the world ; but the present 

 state of geological knowledge does not authorize us to assert 

 universal formations. 



Although we know that all these beds of the general geologi- 

 VoL. I.— 43 337 



