woodworth: geological expedition to brazil axd chile. 1 



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surface of the plateau, was the striking feature in the landscape. 

 Long round swells or hills with graceful curves to the stream ways 

 betokened ever^-Avhere the long continued action of erosion. The 

 excellent topographic maps of this portion of the state b}^ Mr. Horatio 

 Williams begun by the Geological and Geographical Commission of 

 Sao Paulo under the directorship of Dr. Derby made it possible to 

 follow the route intelligently and interpret the general outlines of the 

 erosive history of the district. In a following chapter on the geomor- 

 phology of the region, I have made free use of these maps. 



July 2oth. — In 1908, the passenger service of the railway termi- 

 nated at Bury, but a line in process of construction extended the 

 communication by rail to Ponta Grossa in Parana, and so into connec- 

 tion with points on the south far towards the boundary of Uruguay. 

 As will be shown in the sequel the fresh cuttings of the rocks and 

 surface deposits along this new line afforded an exceptional opportunity 

 to study the geology not only of the underlying Permian tillite beds 

 but also of the superficial gravels and their cover of red earths vari- 

 ously known as terra roxa, etc. This day we proceeded on a flat car 

 some 18 kilometers along the line of construction, completing the 

 journey to Faxina by a sort of carriage known as a "trolley." While 

 traversing the high campos a hailstorm came up from the west with a 

 well-defuied horizontal vortical ring of black clouds, from which hail 

 associated with rain fell so as to coat the ground with hailstones. 

 For nearly an hour after the passage of the storm the small streams 

 now in flood carried a thick load of hailstones. This fall of hail 

 within the subtropical region at an elevation of 900 meters above the 

 sea suggested an inquiry as to the occurrence of hail at lower eleva- 

 tions nearer the equator as a possible factor in the Permian glacia- 

 tion since it appears that in this way ice may be precipitated in 

 regions where snow never falls. 



July 26th. — Being unable to secure a conveyance to Itarare, the 

 day was spent in Faxina. This towTi is underlain by the Devonian 

 sandstone, a light colored to whitish rock, with cross-bedded layers, 

 and occasional bands of white quartz pebbles. Nodules of clay 

 occur also embedded in the sandstone. The strata are well exposed 

 in a ravine on the outskirts of the town. 



July 27th. — Having procured the means for the conveyance of our 

 party to Sao Pedro de Itarare on the boundary of Parana, we journeyed 

 to that place. For most of the day the route lay over the Permian 

 basal sandstones which appeared in the stream bottoms, sometimes 

 with thin beds of white quartz pebbles but without trace of compound 



