WooDwoRTH. — Geological Expedition to Brazil and Chile. 



PLATE 1. 



Valle do Retiro near Petropolis. 



View in the Serra do i\Iar near head of the Valle do Retiro back of Petropolis 

 looking down the Valle do Retiro across the Valley of the Piabanha, a stream 

 flowing north to join the Parahj-ba. Pedra d'Ago, the culminating peak of 

 the radiating ranges, of which the moimtains in the background form a part, 

 attains an elevation of 2,230 metres (7,306 ft.) A region of deep dissection of 

 schistose rocks intruded by bosses of granite and dikes of more basic rocks, 

 the schists and granites probably of Pre-Devonian age as farther south in the 

 Serra do Mar region. Page 7. 



