178 E.. Andrews on the Western Boulder Drift. 
drift deposits, even the boulders being swept off. South of the 
crest the waters were less violent, and deposits commenced. 
In northern Wisconsin, the impinging of the current against 
' the line of precipice flanking Green Bay valley left the marks 
of violent disturbance in the great gravel range. In northern 
Illinois the gravel shades off into clay, and in Central Illinois 
the ancient Pliocene soil is not stripped from the surface, nor 
even the stumps, nor the rotten logs that lay upon it removed. 
This could not be had the country been scraped by the ad- 
vance of a glacier, but might readily occur were it submerged 
by turbid waters coming to rest after their southward rush. 
Another remarkable fact, is the sudden retirement of the 
drift waters after the deposit of the orange loam above men- 
tioned. No sea or large lake remains long at or near the same 
level, without throwing up a beach or eroding a bluff which 
when produced is as indestructible as any other geological 
monument, Ancient beach lines have little tendency to disap- 
pear. The basins of the great lakes like so many cups were 
left full of water, and the ancient beaches are perfectly distinct 
te-day up to their very brims, but outside, on the seaward slope 
there are no such lines. From the uplands of Wisconsin to 
the Ohio river there is a descent of over 1300 feet on whic 
the most diligent search has failed to find a single beach. The 
no beach line crossing either of their routes. It follows that 
the waters at length retired with a degree of suddenness that 
left no time to accumulate beaches. It is possible that this 
sudden retirement, and the consequent rush of waters was the 
cause of the valleys of our streams being excavated to such an 
enormous breadth as compared with the feeble brooks that now 
meander through them. : 
I see it stated in a recent Smithsonian volume that the fossils 
1 ift are fresh water, and of the eastern deposits ma- 
rine. So far as this region is concerned I think this must be a 
mistake, for after fifteen years search I have never been able to 
find nor hear of a well authenticated fossil of any kind in the 
true boulder drift, except such as seemed to belong to the pre- 
vious formations—Pliocene, or older; and even these are surpris- 
ingly rare, when we reflect that the drift action passed over a Te- 
gion already teeming with animal and vegetable life. It can- 
not be, however, that they are totally absent on any theory We 
adopt. If the glacier theory be true, terminal moraines are 
haunted by all sorts of land animals, and where the materials are 
