125 



CHAPTER IX. 

 THE PERMIAN BLANK. 



One whole period of the earth's PaljBozoic history appears to be 

 represented by no monuments in Acadia. The base of the Trias 

 everywliere rests unconformably on the upturned beds of the Carboni- 

 ferous, and the Perm/an system, represented in England by the great 

 magiiesian limestone and its associated beds, and in Germany by the 

 Zechstein and the sandstones and shales above and below it, is absent 

 from our series of formations. The same gap occurs, in so far as 

 known, throughout Eastern North America. It is only west of the 

 Mississippi, in Kansas, and on the eastern slope of the Rocky Moun- 

 tains, that the Permian beds have been recognised. There they 

 consist of limestones, sandstones, marls, and conglomerates, with 

 beds of gypsum resting conformably on the Carboniferous beds, and 

 separating them from the Trias. Their fossils are closely allied to 

 those of the Upper Coal Formation, and very different from those of 

 the Trias, — the latter constituting the beginning of the great Mesozoic 

 division of geological time, the former the close of the Fakcozoic. 



The lapse of time represented by these Permiun beds, and Avhich, 

 though probably shorter than the Carboniferous period, must have 

 been of long duration, is indicated in Acadia only by the disturbances 

 which the Carboniferous beds have suffered before the deposition of 

 those of the Trias, unless we can regard any portion of the great 

 series of beds which I have named the Upper Coal Formation as 

 equivalent in time to the Permian. 



It may be well shortly to inquire if we can bridge over this vacant 

 space by any considerations based on the well-known systems of 

 formations whicli constitute its boundaries. AVe have here first tlie 

 well-establislied fact, that the long and quiet period of the Coal Forma- 

 tion Avas succeeded in Eastern America by an epoch of physical 

 disturbance, in which the Carboniferous rocks were greatly tilted and 

 contorted, and in many places subjected to more or less alteration. 

 The time occupied by these processes we cannot precisely measure ; 



