WOODWORTH: 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 Parand 
near kilometer post 26 on the railroad from Serrinha to Curityba I 
Lf S 
; 
f 
- ° 
. _ ke oS é iy ae ~~ . 
s . ~ : ~ . . ~ 
, . ”-~ . Pid . 
Fig. 31.— a, cross-section of the road cut in which the upper dotted line 
gives the present slope, the lower one, the slope on which 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 
ereases. The relations of the ancient and modern profiles are shown 
in the annexed diagrams. The gravel bed was evidently deposited in 
a crease, the axis 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 gravels were deposited and 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 
