SiUDIES IN THE DRIFTLESS REGION OF 
WISCONSIN: 
THE superficial deposits of this region, aside from the interest 
which would naturally attach to any such deposit, possess a 
certain special interest due to the relation the region holds to 
the adjoining glaciated territory, and the presumption that they 
might furnish a record of certain subsidiary facts which from 
the nature of the case the glaciated region itself could not furnish. 
The field as a whole is a most inviting one for study, present- 
ing as it does considerable variety. But the purpose of this 
article is more especially to describe a particular deposit as seen 
in the vicinity of Trempealeau on the Mississippi River. As 
some knowledge of associated beds is necessary to a full 
understanding, I will briefly describe them in order beginning 
with: 
The loess.— From the upper limits reached by the Champlain 
floods, all the smaller valleys, the lower hills, and, in a less degree, 
the higher hills are covered by a bed of clay, the average thick- 
ness of which may be between twenty and thirty feet, but it 
‘Early in 1894 Mr. G. H. Squier brought to the attention of the senior editor of 
this JOURNAL some observations which he had made on ridges of coarse gravel and 
bowlders in the vicinity of Tomah, Wis., which lies in the heart of the driftless area. 
It was his opinion that the formations constituted evidence of local glaciation. 
The débris was described as made up of chert and sandstone too coarse to be 
easily accounted for, in his opinion, by floods. It formed ridges on the slopes or 
side-plains of the valley and neither had the form of definite terraces nor of axial 
valley drift. No glacial striation either of the transported rock or of the rock zm site 
were observed, nor were glacial contours recognized in the configuration of the valley, 
nor distinctively in the ridges of débris. These deficiencies of evidence seemed less 
important however than the apparent absence of limestone débris. The deposit in 
question seemed to be made up wholly of sandstone, chert, and other residuary 
material. As limestone lay on the summit and formed the protecting crown of the 
highlands in which the valleys head, and as its habit of outcrop is such that it could 
readily yield massive blocks to glaciers occupying the heads of these valleys, and 
further, as limestone is habitually present in morainic débris formed in such situations. 
825 
