EXFOLIATION OF MOUNTAIN MASSES. 



273 



Aside from the general description of the process of exfoliation by which 

 these forms are produced, it is here in place to give the explanation 

 offered by Agassiz for these particular peaks. He says that the strata of 

 *' which they are formed are nearly or quite vertical, and that the harder 

 sets of beds alone have remained standing, the softer intervening beds 

 having been gradually disintegrated."* 



*^^^**^**^^^^-%;: '^'"- 



Figure 3. — The Corcovado from Botafogo, Rio de Janeiro. 



There are several impressive examples of exfoliated mountain masses 

 in the immediate vicinity of Nova Friburgo, some of which are shown in 

 figure 5. 



* A Journey in Brazil. Professor and Mrs L. Agassiz. Boston, 1868, pp. 486, 490, 492. Geology 

 and Physical Geography of Brazil. Ch. Fred. Hartt. P. 16. Gardner says that at Sapueaia the Rio 

 Parahyba follows the strike of the gneiss. Travels in Brazil, p. 537. 



