74 THE MOUNTAIN. 



them and the next lines of elevation, forming ridges called 

 by different names, the region presents the character of ele- 

 vated broken and irregular valleys. The surfaces of these 

 valleys (which, however, can scarcely with propriety be called 

 valleys) is constituted of a series of hills, separated by deep- 

 washed gulleys and ravines, of every conceivable shape and 

 dimension, from steep and precipitous gorges to gentle and 

 flowing vales. 



These hills have something of a mountainous character, 

 and the whole surface between the highest ranges of the 

 ridges and mountains is sometimes, though very incorrectly, 

 called "the Mountains." 



The whole group of Appalachians, with its intervening 

 valleys, has for its bone-structure or skeleton, that magnifi- 

 cent system of paleozoic or fossiliferous rocks which are so 

 largely developed in North America, and which have scarcely 

 a parallel in any portion of the earth's crust yet subjected to 

 geological scrutiny. 



To this immense mass of sedimentary deposits, embraced 

 between the horizon of the crystalline, hypozoic, or gneissic 

 rocks and the top of the coal series, the general term, "Ap- 

 palachian," has been applied by some geologists. " This series 

 of rocks, more than thirty-five thousand feet thick in some dis- 

 tricts, is made up of a number of separate formations, cha- 

 racterized by distinctive features in mineral composition and 

 organic contents," revealing in majestic hieroglyphics the 

 history of an immeasurable chain of phenomena occurring 

 through unreckoned centuries of time, in an unbroken sequence 

 of deposits, closely united by a continuous affiliation of or- 

 ganic forms and general geological characters. 



" The whole pile is the demonstrable record of an immea- 

 surable and continuous epoch, the deposit of one vast oceanic 

 basin."* 



As the strata are in the main conformable, they constitute 

 a series, divisible into a number of separate members, or for- 



* Rogers. 



