296 The American Geologist. November, isw 
literated bj T ice action. This last question involves the prob- 
lems of subsidence of t he region and of the character of ice 
dams. The writer regards the beaches as substantially formed 
at sea-level (as some of the beaches unquestionably were), 
although the outlines may have been obstructed by > glaciers, 
iioe-bergs, or local ice accumulations, or perhaps the north- 
eastern continuity of the beaches is obliterated by recent 
faults. These are unsettled questions. Much is still to be 
done in the survey of the ancient lakes, yet we have some in- 
teresting contributions to record concerning them, even with- 
out inquiry here as to the still unread history." 
Fragments of beaches occur in the peninsula between lake- 
Ontario, Erie and Huron, up to altitudes of about 1,700 feet : 
and terraces are found in the Genesee valley at a much 
greater bight, besides others at high levels elsewhere in the 
lake region. But when we descend to an altitude of 778 feet, 
at the head of lake Erie, we are at a beach of great extent (to 
the northeast this rises several hundred feet) ; and one still 
more extensive is reached by descending to 653 feet. All 
the higher shore developments are the remains of the first 
waters that covered the drift at the close of the Pleistocene 
period, whether they were ice-bound arms of the sea, or held by 
glacial dams, or by undiscovered land barriers since deformed 
by terrestrial movements. The beaches were water-levels, but 
now they rise toward the north and east in increasing ratio. 
At the head of lake Erie they are nearly level ; at the eastern 
end of this lake the northeastern rise is between three and two 
feet per mile, according as we take the uplift on the higher or 
lower beaches. East of Georgian bay the deformation is four 
feet ; and near the outlet of lake Ontario it is from five to six 
feet per mile towards the northeast, but increases onward to 
seven and a half feet per mile. These rates of ascent are re- 
corded in shores not the highest; and there were man}' lower 
stages of the lakes. 
/'/. Warren Water. The contracting waters of the Great 
Lakes region, represented b} 7- the succession of beaches, the 
writer named the Warren water, — the ancestor of all these 
lakes; and its lowest strand is the Forest beach, which at the 
head of the Erie basin has an elevation of 653 feet above the 
Bea. This lake, during part of its history, covered 200,000 
