SECTIONS OF THE REGION 



81 



valley floor ; s-{- 1 is some 50 meters above s -{- 2, and s is not over 100 

 meters above s +1. 



UST-KA TA W D1S8EQTI0N 



Although the rocks are changing, the relative elevation and breadth of 

 the series of grade-plains seen at Simsk are continued eastward. At 



Figure (J. — Frofile near Usf-Kataw. 



Ust-Kataw the same two dissection planes are found between this up- 

 land and the river bed (figure 6). 



TUREZVSK PLAIN 



On the road to Bakal we passed the little village of Yurezusk, where 

 there is a broad expanse of the plain formed in the second epicycle of 

 dissection following the long cycle of planation. This is unusually broad 

 with reference to the preceding epic3'cle (figure 7), and the form suggests 



Figure 7. — Yurezusk Grade-plain. 



that the rocks here have been easily worn awa3^ The upland level on 

 Sigalga mountain in this region is 1,400 meters above sealevel. 



SUKA MOUNTAIN 



One of the broadest plains representing river grades cut below the up- 

 land is seen west of Suka mountain (plate 10, figure 2). This view shows 

 the accordance in elevation of the summits (b + 1, of figure 7), which 

 are several hundred meters above the lower level grade-plains (b + 2), 

 and are also some 200 meters below the summit-level plane in this re- 

 gion. The broad tops of Suka and the surrounding ridges rise to some 

 1,200 meters above the sea. 



TAGANAi' SECTIONS NEAR SLA TOUST 



In the region around Slatoust the distinction between these three 

 plains is most clear and decisive .(figure 8). There are several places 



