226 
BIOLOGY: A. P. DACHNOWSKI 
Proc. N. a. S. 
systems, while within the later and more recent positions of the ice border 
the deposits are younger in age and consist of only a few layers of peat. 
The lack of structural diversity in the uppermost layers of the older de- 
posits is related probably to the distance of those deposits from the direct 
climatic influence of the later glacial sub-stages. 
TABLE I 
Correlation of Glacial, Climatic, and Life Stages since the Last Ice-Age 
IN THE United States 
GLACIAL 
SUB-STAGES 
GREAT LAKES 
STAGES 
CLIMATIC 
CHANGES 
ESTIMATED 
TIME 
ANIMAL 
REMAINS 
HUMAN 
REMAIN 
VEGETATION 
SUCCESSION 
8. Present 
7 . Recent 
(post-gla- 
cial) 
6. Port Hu- 
ron 
Lake Michi- 
gan 580 ft. 
Post-Nippis- 
sing 
Nippissing 
530-590 
Champlain 
Sea, Niagara 
Algogum 608- 
609 
Rising dry 
Temperate, 
humid 
A. D. 
— o — 
B. C. 
7000-5000 
B.C. 
Mound 
builders? 
Forest 
Spagnum 
bogs and 
marsh 
Forest 
Marsh 
morainic 
system 
5 Lake Bor- 
der 
Lundy-Duluth 
615 ft. 
Whittlesey- 
Chicago- 
Saginaw 
Temperate 
Dry 
Cool, humid 
Mastodon 
Flint 
implements 
Forest 
Marsh 
morainic 
system 
4. Valparaiso 
Maumee 805 
ft. 
Late Wiscon- 
sin drift 
Warm, dry 
Warm, hu- 
mid 
11000-8000 
B.C. 
18000-16000 
B.C. 
Mastodon 
Forest 
Marsh 
Kalamazoo 
morainic 
system 
3. Blooming- 
ton 
Loess formed 
Cool, windy, 
dry 
Temporary 
ameliora- 
tion 
Cold, hu- 
mid 
25000 B.C. 
Steppe? 
Low shrubs? 
morainic 
system 
2. Shelby- 
ville mo- 
raines 
Cold 
28000 B.C. 
Tundra? 
1 . Wisconsin 
driftbor- 
der 
Arctic 
35000-30000 
B.C. 
To the practical worker it is obvious that a better understanding of 
the structural differences in peat deposits implies a more correct estimate 
of their economic value. 
The profile sections visualize the stratigraphic relationship of American 
and European peatland and they suggest the value of a more detailed 
