On American Geological History. 415 



and Massacliiisetts add to tlie evidence. The quiet required by 

 the continent for the regular succession and undisturbed condi- 

 tion of the rocks of tlie Silurian, Devonian, and Carboniferous 

 formations, shows that in neither of these aa:es could such vast 

 results of raetamorphic action and upheaval have taken place. 



The length of time occupied by this revolution is beyond 

 estimate. Every vestige of the ancient Carboniferous life of the 

 continent disappeared before it. In Europe, a Permian Period 

 passed, with its varied life ; yet Americi, if we may trust nega- 

 tive evidence, still remained desolate. The Triassic Period next 

 had its profusion of living beings in Europe, and over two thou- 

 sand feet of rock ; America through all, or till its latter portions, 

 was still a blank : not till near the beginning of the Jurassic 

 Period do we find any traces of new life, or even of another 

 rock above the Carboniferous. 



What better evidence could we have than the history of the 

 oscillations of the surface from the earliest Silurian to the close 

 of the Carboniferous Age, and the final cresting of the series- in 

 this Appalachian revolution, that the great features of the con- 

 tinent had been marked out from the earliest time ? Even in 

 the x\zoic, the same northeast and southwest trend may be ob- 

 served in northern New York and beyond Lake Superior, show- 

 ing that, although the course of the great Azoic lands was partly 

 east and west, the same S3^stem of dynamics that characterized 

 succeeding ages was then to some extent apparent. 



The first event in the records after the Appalachian revolution 

 was the gathering up of the sands and rolled fragments of the 

 crystallized rocks and schists along the Atlantic border into 

 beds ; not over the whole surface, but in certain valleys, which 

 lie parallel with the Appalachian chain, and which were evi- 

 dently a result of the foldings of that revolution. The beds are 

 the red sandstones and shales, which stretch on for one hundred 

 and twenty miles in the Connecticut valley : and similar strata 

 occur in southeastern New^ York, in New Jersey, Yiginia, North 

 Carolina and Nova Scotia. These long valleys are believed to 

 have been estuaries, or else river courses. 



The period of these deposits is regarded as the earlier Juras- 

 sic by Professor W. B. Rogers. Dr. Hitchcock supposes a por- 

 tion of the preceding or Triassic^ Period to be represented.* 



* This Red Sandstone, after being known for a while under the name of 

 Old Red Sandstone," was long called the " New Red Sandstone," it being 



