THE ORIGIN OF THE HELLS OF THE WISCONSIN. 
C. R. VAN HISE, PH. D. 
Professor of Geology in the University of Wisconsin. 
The reports of the State Geological Survey of Wisconsin show 
that the Paleozoic formations constitute a gentle southward 
plunging anticline the axis being a north-south line near the 
center of the state. Doubtless the axis of the anticline is also 
curved, which implies a bending in a direction transverse to 
the more conspicuous bending. 
So far as observed, in the south central part of the state the 
prominent joints are approximately in east-west and north-south 
directions, with, however, a good deal of local variation and in 
places another set of joints in a third direction. That there is 
a connection between this jointing and the folding is at once 
suggested, the joints being a rectangular system of fractures 
produced by the folding, and their directions being controlled 
by it, as explained by Daubree and amplified by others. 
The well known Dells of the Wisconsin constituting a cut 
through a broad flat ridge of Cambrian sandstone have been 
described by Chamberlin as eroded subsequently to the glacial 
epoch, this river finding a new channel, because of a dam of glac¬ 
ial deposits which obstructed its old passage through the Baraboo 
quartzite range. In what follows the courses of the dells of the 
minor streams which flow into the Wisconsin are first considered, 
the course of the Wisconsin itself being excluded. A close 
examination of these dells show that they were controlled in their 
location by the rectangular system of joints above mentioned. 
For instance, in following one of the side streams, one may first 
go in a north-south direction, then turn to an east-west direc¬ 
tion, then again in a direction north and south, and then in a 
direction east and west, etc. While the main creek or brook 
thus has a rectangular course, at any one of the turns a lesser 
stream may come in along the other system of joints. The dells 
