Glacial Deposits In Dnffless Area. — Sardeson. 4-01 
considers it to be, has been sc-attered higli above its oi'iginal 
bed ill the -'driftless area," the same as at Freeportin the nor- 
thern drift. Taking for example the railway cutting through 
the Shakopee formation next south of Argyle station; there 
the residuary clay contains "Freeport gravel," lighter colored 
chert from the Galena (Trenton), blocks of Saint Peter sand- 
stone, and common and or)litic chert from the Shakopee for- 
mation itself. The chert fragments in ,the clay may be ex- 
plained as residuary debris from higher although in part no 
longer adjacent limestone ; except the "Freeport gravel" which 
seemingly has ascended. 
Mr. Hershey's theory of the "Freeport gravel" harmonizes 
with my own observations in that the red-brown chert has 
been seen in the valleys, only, and inasmuch as it is scattered 
back upon the sh)pes above the river's plain and beyond where 
the river's bed could liave been at any stage of its develop- 
ment, it is necessary to assume that in the "driftless area," 
too, the "Freeport gravel" pebbles have been again transport- 
ed by glaciers. Much depends upon the future determination 
of the "Freeport gravel" liere referred to, in the "driftless 
area." 
Deposits not covered by the undisturbed loess loam I have 
neglected to describe althougli some of them could be of gla- 
cial origin, as for example the boulders at Jonesdale below 
Dodgeville. There upon the west side of a ridge the south 
end of which forms a high, steep bluff over the river opposite 
the mill, is found a heap of rounded sandstone boulders one 
to twelve feet in diameter, covering an area tifty by flftj^ feet, 
about twenty feet deep, and scattering up and down the slope 
but not extending back along the exposed side of the hill, 
in the direction from which they would liave been trans[)orted 
by a glacier. They are probably boulders of disintegration, 
pushed from tlieir resting places along the side of the hill 
and left piled in a heap. The corresponding southeast side of 
the same ridge shows no similar accumulation, but near the 
top are boulders of disintegration in phice, nearly covered by 
sand and vegetation, which the heaped-u]) boulders are not. 
.). I). Whitney, who tirst called the "lead region" "driftless." 
observed a similar occurrence of boulders in the midst of the 
area. He writes :* 
*Geoi();j:y of Wisconsin, vol. i. ISlil. p. 137. 
