WOODWORTIi: GEOLOGICAL EXPEDITION' TO BRAZIL AND CHILE. 109 



of the older glacial episodes comparable to that of the Columbia 

 gravels south of the terminal moraine on the Atlantic slope of North 

 America. 



A short distance west by south from Araucaria Station in Parana 

 near kilometer post 26 on the railroad from Serrinha to Curityba I 



C. ^ 



Fig. 31. — a, cross-section of the road cut in wluch the upper dotted line 

 gives the present slope, the lower one, the slope on wlilch the old gravels 

 were deposited; b, cross-section of the spur on right of railway; c. theo- 

 retical restoration of both sides of a gravel-bearing hill, the upper portion 

 being removed in the segregation of the gravels. 



noted, in a railway cut through a spur, evidence that these old gravels 

 were deposited on a steeper slope than that of the modern neighboring 

 creases. The relations of the ancient and modern profiles are shown 

 in the annexed diagrams. The gravel bed was evidently deposited in 

 a crease, the a.xis of which corresponds with that of the present spur 

 as above explained. From the consideration of such a case it be- 

 comes evident that the existing smoothened contour of the ground is 

 due to the removal of the crests of old spurs and ridges and the ac- 

 cumulation of the coarse detritus near the bases of the slopes, and thus 

 that a topography of sharper outlines preceded the present cycle. 

 This means a considerable lowering of the elevations of the region 

 since the old gra\'els were deposited ajid confirms the idea of an early 

 Pleistocene date at least for the age of these deposits. 



On the baselevelled plain about Curityba where rounded ridges of 

 mature dissection modified by deep weathering are interspersed 

 between shallow water courses the cuts show many signs of the gentle 

 processes of solution by which the surficial rocks have been removed. 

 In one such cut near the Meteorological Station in the west bank of 



