PENNSYL VAN IAN-PERM I AN GLA CIA TION 



48s 



In Figure 15 is shown an example of recent uncovering of a 

 fluted granite mass. This view shows in the foreground a small 

 area of fluted granite standing on a low flat which has been 

 exposed by stream erosion. In the background is seen a bank rising 

 above the flat, which is the general level of the surrounding plain of 

 the Permian Red Beds. The Red Beds once extended over the 

 intervening low flat and completely covered the granite mass, but 

 stream erosion has recently removed the Red Beds down to the inter- 

 vening low flat, thus bringing to view the buried granite with its 

 fluted surfaces. In addition to the work of streams ordinary slope 





Fig. 15. — View showing recent uncovering of grooved granite 



wash on the sides of the mountains, has exposed the grooved sur- 

 faces as in such examples as Figures 8 and 11. 



An additional line of evidence in support of the view that the 

 fluted granite surfaces are ancient features, brought to the surface 

 by the removal of the valley fill, is the very obvious fact that these 

 features are now in process of obliteration and destruction wherever 

 exposed to present weathering conditions. 



The present type of wind and weather action is fairly well 

 illustrated in Figure 16, which represents an exposure at the head 

 of Devil's Canyon and well above the zone of valley fill and grooved 

 granite surfaces. This granite mass is an isolated stack, exposed 



