STUDIES IN THE DRIFTLESS REGION OF WISCONSIN 1 89 



confluent valleys first described, in which the highest portion of 

 the rim is toward the northwest, and consists of a high and 

 rather long bluff, somewhat crescentic in form. The north rim 

 of the valley consists of a much lower ridge, nowhere reaching 



Fig. 7. Contour sketch map of the easternmost of the two confluent valleys first 

 described in the last article. (The lower part is shown in Fig. 1.) The enclosing rim 

 of the valley reaches the limestone horizon at only two points. One of these is the 

 long bluff, a. The other would fall a couple of inches outside of the lower right-hand 

 corner and is the same as the one shown at g, Fig. 4. At b occurs the train of lime- 

 stone debris. Its downward extension is concealed by loess, c, knob of hard, ferru- 

 ginous sandstone. 



Scale 800' to an inch. Contour lines at intervals of 25'. 



to the horizon of the limestone. In proceeding eastward from 

 the base of the limestone at the northeast end of the high bluff, 

 limestone debris is lacking for some three or four hundred feet. 

 It then appears suddenly on the top of the ridge, extending to 

 an unascertained distance downward on the inside. A little fur- 

 ther eastward the upper edge of the debris begins to fall a little 

 short of the top of the ridge (on the inner side), and from that 

 point it continues to decline at a nearly uniform rate, making an 

 angle of about 4 or 5 with the horizon. The limestone is in 

 sufficient abundance to wholly cover the ground up to almost the 

 extreme limit of its occurrence, when within the space of a foot 



