SCENOGRAPHICAL GEOLOGY. 



627 



a plateau of older formations of schists entirely isolated from any other 

 deposits of the same age, yet with highly inclined strata!. These are, 

 unlike the sugar-loaf mountain 

 structures, composed of nearly 

 horizontal strata, which have 

 been rounded by erosion. 

 These elevations, like the lat- 

 ter, are relics of a once wide- 

 spread blanket of rock; but 

 the fragments have been doub- 

 led up by plicating forces, and 

 their former connection seems 

 difficult to believe. Their pres- 

 ent separation is- not due to- 

 erosion alone. It is also likely 

 that there have been some 

 special uplifts of land in Con- 

 nection with each of these 

 summits. In New Hampshire 

 tliese mbUntains are likely to 

 be confounded with thoise of 

 gfahiiSc" origin, like the Strat- 

 ford peaks. 



I do not- need to speak fur- 

 ther of our r-avines and gorges, 

 as- the most prominent ones^ 

 have been described. Fig. 

 88 may' illustrate sbriie of ouir 

 broad, sloping, valleys, where 

 level plateaus have been form- 

 ed by the- transportation of 

 drift material. Oiir grlftat'ei* 

 valleys bf rtiis" ffbrf a.t6 too 

 extensive for r'epresentation. 

 Such are the Conway plains, 

 the barren expanse in Madison and Ossipee, and many other districts 



