78 Dr. F. V. Hayden on the Primordial Sandstone 
that the source of all the sediments composing the Primordial 
rocks in the west can be traced to the underlying rocks in the 
vicinity. 
4. There are no indications of long continued deep water in 
the Primordial sea so far as the West is concerned. If we ex- 
amine the lower part of the Potsdam sandstone we find that the 
physical conditions which ushered in this period were quite 
violent, as is shown by the conglomerate character of the rock. 
assing upward this conglomerate graduates into a rock com: 
posed of granules of quartz and small plates of mica cemen 
with calcareous matter, and about midway in the formation we 
have a fine, very ferruginous calcareous sandstone, in thin 
layers, filled with fossils in a very good state of preservation. 
The condition of the organic remains, the fineness of the i- 
ment and the perfect horizontality of the laminz of deposition 
indicate a short period at least, of quiet water. As we continue 
upward the rocks begin to show the shifting nature of the cur- 
rents, shallow water and perhaps a proximity to land, by ob 
ique laminze of deposit, ripple markings and fucoidal remains. 
The upper portion of this rock contains no fossils, nor were the 
8 gam conditions such as to have preserved them even if they 
ad existed. 
400 feet. In Tennessee Prof, Safford finds several thousand 
feet of rocks, which he refers to this age, and in Texas where they, 
seem to be quite well exhibited and to yield a large number of © 
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