1897.] The Inferior Boundary of the Quaternary Era. 109 
soils. None of these conditions were present in any marked 
degree during the Lafayette period, as the color and composi- 
tion of the marine deposits and interior river gravels positively 
demonstrate. 
The causes which produced glaciation not yet having begun 
to operate on the continent, the extension of the warm gulf 
waters to the head of the Mississippi embayment and the 
borders of the southern Appalachian province, must have in- 
troduced a milder climate into the upper and central portions. 
of the Mississippi basin, providing no counteracting influences. 
were brought to bear. The probable slight elevation of the 
continent northward from the Lafayette coast certainly did 
not possess sufficient power to modify the climate to any ap- 
preciable extent. Therefore, it seems evident that any change 
of climate in the eastern half of the territory now included in 
the United States, which may have accompanied the opening 
and culminating stages of the Lafayette epoch, must have been 
in the nature of increasing mildness instead of an increase in 
the severity of the climate. In short, so far as the climate is- 
concerned, all the evidence which is at present known to exist 
is demonstrative of the practical continuance of Tertiary con- 
ditions to the close of the Lafayette epoch. Hence, those 
geologists who wish to include the Lafayette epoch under the 
Quaternary era, must base their claims on some other natural 
feature than climate. Mere earth movement, if its effects are 
not prominent, cannot be considered as instituting a new era, 
and, as the elevation of any part of America or the world at 
large in the Lafayette epoch is not known to have been great 
in vertical extent, and to have seriously effected climates, 1t- 
can hardly constitute a legitimate reason for placing the epoch 
in the Quaternary era. 
Immediately following the close of the Lafayette epoch there 
Was a period of pronounced elevation of the continent. This 
is indicated by the valleys which have been eroded beneath 
the surface of the Lafayette deposits, by the great depth of the 
coastal valleys now submerged to form the fiords of the coasts 
of British America, Alaska, Scotland, Norway, Patagonia and 
other portions of the earth’s land area; and no less truly 
