WooDwoRTH. — Geological Expedition to Brazil and Chile. 



PIATE 2. 



Granite Boulders due to Weathering. 



View ou the shore of FlorianopoUs Island, Santa Catharina; on shoie of bay 

 south of the city of FlorianopoUs. This type of surficial boulder, due to 

 secular weathering of the granite, is common in the granitic regions along the 

 slopes and at the base of the Serra do Mar, particularly at sea-level. The 

 well-known boulders of the "Furnas das Agassiz" at Tijuca, which with other 

 phenomena gave rise, at the time of the Thayer Expedition to Brazil, to the 

 now abandoned hypothesis of the glacial origin of these detached blocks, 

 belong in the same class of effects of secular weathering since Tertiary times. 

 Page 113. 



