PLATE 7. 
Figure 1— Contortep Banps In Ciay, Woopsvitis, N. H. 
Two specimens are photographed in this figure. On the left there are ten well-shown annual 
deposits. The three lower bands are horizontal and those above show contortions and faults. In each of 
the bands there appears a characteristic which is very common in the glacial clays and also in the glacial 
slate at Squantum. It will be noted that on top of the winter or dark layer of clay is a thin layer of 
silt which shows in light color. Above this silt layer is a thin layer of clay. Above this comes the 
much thicker layer of silt denoting summer deposition. This silt gradually becomes finer upward and 
merges into the next clay or winter deposit. It is inferred that where the thin layer of silt follows the 
clay the cause may be a breaking up of the ice in the spring with temporary high-water conditions from 
the melting. This condition may then be followed by another freeze and quiet conditions of deposi- 
tion for a short time, followed by normal summer conditions as indicated by the thicker layer of silt. 
It is also possible to interpret the thin silt layer in a different way. If the territory in front of the ice 
should be devoid of snow, a high wind might easily spread dust or even sand over the winter ice, cover- 
ing the area of clay deposition. On the melting of such ice in the spring this wind-blown material 
would settle to the bottom. In this way a layer of coarse material might become intercalated between 
the fine clays. The peculiar character described above is not always present in the glacial clays but 
is very common. The remarkable contortions on the right are noteworthy. 
Figure 2.— Contortep Guactan Cray, Woopsvitie, N. H. 
