396 The American Geologist. December. i897 
of loose sand covered mainlj by vegetation, often by large 
trees and former]}^ no doubt by primeval forest, have been seen 
by me in Hennepin, Ramsey, Washington. Anoka, Isanti and 
(Chisago counties in Minnesota, and although my exploration 
lias been merely incidental and not extensive, still there seems 
to be evidence enough to warrant the belief that deposits of 
wind-driven sand in this region are really very extensive. In 
all cases except one these sands have been interpreted as wat- 
er deposits* — modified drift — the evidence for which these 
sands do not bear. There is true modified drift too in the 
region. The ancient wind-driven sands are also extensive 
and ver}^ evidently the little desert in Anoka county, describ- 
ed by Warren Upham, represents only Vae remnant of a much 
larger one. 
The source of the sand here is the drift, since the whole 
region is drift-covered. Of course already sandy areas have 
afforded conditions for the greatest accumulation and hence 
the sand is often associated with the modified drift. It is 
spread or heaped over terraces and over hills, especially 
deep on top of low hills, as near Harris. 
Associated in the neighboring area is also a loess loam, seem- 
ingly of the same age, for example in Washington and Dako- 
ta counties, Minnesota. Winchell (N. H.) writes of the for- 
mer county : "on the most elevated tracts, is found a light 
clay-loam, of a yellowish color, which is comparable to that 
found in similar situations in Dakota and Goodhue counties." 
(Vide op. eit. p. 380, 1. 33). The loam of Goodhue county is 
the pre-Wisconsin loess, the other post- Wisconsin. Salisbury 
has recently interpreted some deposits of loess upon the Wis- 
consin, although the deposits described by him are not adjac- 
ent to the Anoka desert. "Heretofore loess has not been known 
to occur in or above the drift of the Wisconsin epoch; but 
during the past summer it has been found in connection with 
this formation at several points in Wisconsin, namely near 
Green lake. Devil's lake and Ableman's."f 
Besides the sand and loess deposits that are known to lie 
upon the Wisconsin drift there are probably other perhaps 
larger contemporaneous ones. Yet the post- Wisconsin as 
*Vide loc. cit. p. 254, fig. 16, p. 295, 297, 352, 371, 380, 404, 411. 
tSalisbury, 1896, Jour. Geol. iv, p. 930. 
