104 LAE Wi QURNAEVOPAGROLOGN, 
appears to be in favor of classifying the Lafayette as the upper member of 
the Tertiary (Pliocene) formation, and so I have represented it on the geolog- 
ical map of the state” (p. 81-82). 
This would seem to be sufficiently explicit, were not some doubt 
thrown on this correlation in other connections. Thus we find the 
following : 
‘““The great amount of erosion which took place after the deposition of the 
Lafayette, and before that of the next overlying deposits, has been urged as 
an objection to the placing of the Lafayette in the same category with the 
Pleistocene, but the same objection might, with equal force, be urged against 
classifying it with the Tertiary, since an equally great, if not greater, amount 
of erosion occurred between the deposition of the Miocene beds and _ those 
of the Lafayette”’ (p. 82). 
This last statement is certainly a little curious. If the alternative 
were between classifying the Lafayette as Pleistocene or as Miocene, the 
point here made would have force. But this is not the alternative, and 
Dr. Smith does not really so regard it, for he classifies the Lafayette, 
not as Miocene or as Pleistocene, but as Pliocene. If the argument of 
the last citation had been urged as a reason for separating the Lafayette 
from both the Pleistocene and the Miocene, making it Pliocene, as 
Dr. Smith has really done, it would seem weighty. ‘To use this argu- 
ment for the purpose of raising the question as to whether the Lafay- 
ette is not really Pleistocene, is to take the position that an uncon- 
formity may be admitted in the Pleistocene, but not in the Tertiary. 
It is to take the position that different members of the Pleistocene may 
be much more sharply separated from each other than Pliocene from 
Miocene. This is a position which we believe to be untenable. The 
above citation does not seem to the writer to have weight against the 
classification of the Lafayette as Pliocene, for it is not clear that there 
may not have been an erosion interval between the Miocene and the 
Pliocene. It is true that unconformities are known in the extra-glacial 
Pleistocene, but they are much less considerable than the unconformity 
above the Lafayette. Of much more significance, in the judgment of 
the writer, is the constitution and physical condition of the Lafayette. 
Dr. Smith says: “As yet the existence of material of glacial origin 
among the Lafayette beds, seems not to have been proven beyond 
question” (p. 81). This does not seem to quite express the true con- 
dition of things. The Lafayette beds have been widely studied by 
many observers. Not only has glacial material not been proven to 
