TIME DIVISIONS OF THE ICE AGE. O07 
EPOcHS AND STAGES OF THE GLACIAL PERIOD. 
I. The Glacial Epoch. 
1. THE CULMINATION OF THE OZARKIAN EPEIROGENIC UP- 
LIFT, in the later part of the Lafayette period, the earliest of 
the Quaternary era, affecting both North America and 
Europe, raised the glaciated areas to so high altitudes that 
they received snow throughout the year,and became deeply 
ice-enveloped. Submerged valleys and fjords show that 
this elevation was 1,000 to 4,000 feet above the present 
height.* 
Rudely chipped stone implements and human bones in the 
plateau gravel of southern England, 90 feet and higher 
above the Thames, and the similar traces of man in early 
(Juaternary sand and gravel deposits of the Somme and other 
valleys in France, attest man’s existence there before the 
maximum stages of the uplift and of the Ice age. America 
also had been already peopled, doubtless by preglacial 
migration from Asia across a land area in the place of the 
shallow Bering Sea. 
The accumulation of the ice-sheets, due to snowfall on 
their entire areas, was attended by fluctuations of their 
gradually extending boundaries, giving the Scanian and 
Norfolkian stages in Europe, the Albertan formation of very 
early glacial drift and accompanying gravels, described by 
Dawson, in Alberta and the Saskatchewan district of western 
Canada, and an early glacial advance, recession, and re- 
advance, in the region of the Moose and Albany Rivers, 
south-west of Hudson Bay. In that region, and westward 
on the Canadian plains to the Rocky Mountains, there seem 
to thus have been three stages recognizable in the glacial 
results of the epeirogenic uplift, namely, the ALBERTAN STAGE 
of early ice accumulation, the SASKATCHEWAN STAGE of 
abundant melting and considerable retreat, and the ensuing 
great Kansan growth of the continental icefields. 
A deposit of glacial drift, the lowest and oldest observed 
* The amount of uplift as compared with the present level of the 
ocean was greater than above stated, as shown by Professor J. W 
Spenser for the American side, and by Professor Edward Hull for tke 
eastern side of the Atlantic, in the latter case amounting to 6,000-7,000 
feet, at which depth the submerged river-valleys (such as the Loire, 
the Adour, the agus, and the Congo) open out on the floor of the 
abyssal ocean. See Trans. Vict. Jnst., vols. xxx, xxxi, and xxxii.— 
Epiror. 
