PLATE 3. 
Figure 1.— Criay anp Sint Layers at Lisson, N. H. 
In this figure the banding shows a sudden change of the conditions of deposition near the top. 
At the bottom the bands are regular in interval and fairly thin. About eight inches from the bottom, 
at the lower end of the handle of the trowel, there is a sudden appearance of a band about two 
inches thick with a larger proportion of silt and less clay. This layer is followed by bands having 
about equal amounts of clay and silt. Then come thinner bands with a very regular interval for two 
feet. Suddenly, near the top a marked increase in the thickness of the banding can be seen. It is 
suggested that such a sudden addition of bulk.of sediment might be satisfactorily explained by a shifting 
of the glacial stream nearer to this location. 
Figure 2.— Irrecutar Banpine or Cuay anp Smut at Norte Batu, N. H. 
View taken at a section about 150 feet above the Ammonusuc River. No banding can be found 
in the Squantum slate with more irregular intervals of deposition than are found here. As has been 
noted (p. 39), in coarse sediments no regular intervals in the banding need be expected on account 
of the changing nature of streams coming from a glacier. Only in undisturbed places can undisturbed, 
regular banding be expected. In this case the sediment is coarser than at Woodsville; the clay has 
less plasticity and the silt approaches a very fine sand. The sizes of the sediments are about the same 
as in the average Squantum slate, such as is found in positions near the tillite. The irregularities found 
here are probably due to shifting and varying streams, from year to year. It does not seem probable 
that variations in yearly temperature could account for the various thicknesses shown, although as 
indicated (p. 39) this may be possible. 
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