I. Bowman — Physiography of the Central Andes. 199 



tance away. "We have here one of the great planes along 

 which a major segment of the earth's crust is undergoing 

 adjustment, the line of movement being oftentimes indicated 

 by earthquakes and the amount by recently uplifted shore 

 forms of unmistakable identity. 



At the port of Payta in northwestern Peru one may obtain 

 a very clear notion of the recency of the crustal movements 

 that have affected the land thereabout. On the left of figure 2 



Fig. 3. 



Fig. 3. Coastal Terraces at Mollendo, Peru. 



a sea terrace only a few feet above sea level may be observed. 

 It runs up each of the reentrants and rounds all the spurs with 

 even contour. Its materials are of exactly the same sort as 

 those in the existing beach below it and the shells occurring in 

 it are likewise identically like those of the present shore. It 

 appears to have been formed but yesterday, so fresh are its 

 details of structure and relief. Just outside the port, at the 

 Punta de Foca, are wider terraces cut into the rock as well as 

 the soft sands and gravels that overlie the rock. It is now 

 being scored by the intermittent streams dependent on the 

 seven-year rains, and is being cut off on the seaward side by 

 wave action. Its smooth upper surface in the interstream 

 areas is still strewn with wave-rolled material ; and the beach, 

 except for the work of the scoring streams, seems as in the 

 previous case to have been exposed but yesterday. 



