Geology of the St. Croix Dalles. — Berkeii. 351 
line and most of them above the 900-foot line. Thej' issue from 
drift areas, because of local impervious layers whicli check 
the underground escape of the descending waters. While such 
springs are numerous in Wisconsin, there ai*e few on the Min- 
nesota side of the river. The most notable examples are found 
in Sec. 7, T. 34 N., R. 18 W., where one of the number issues 
at an elevation of 1,000 feet. It is the water from these 
springs which is so much used in the maintenance of the sev- 
eral trout ponds or farms located within the district. The 
three now developed are in Sec. 6, T. 34 N., R. 18 W., Sec. 24, 
T. 34 N., R. 19 W., and in Sec. 14, T. 33 N., R. 19 W. 
The water discharged from the springs of the district is. in 
most cases, exceptionally clear and wholesome. In a few 
places along the river much calcium carbonate is deposited 
from these waters in the form of travertine and crystallized 
calcite. In a few places iron is carried in considerable 
amount, and still more rarely, on account of local accidental 
contamination, the water is too impure for domestic use. But 
these are exceptional conditions. 
Abandoned Eiver Channels. There are several well-marked 
abandoned channels along the present course of the river. Two 
of these are referred to under the heading of terraces, but 
each will here be mentioned and their location noted: 
1. The sandy bottom on which the wagon road runs through Sec. 2, 
T. 31 N., R. 19 W., on the west side of the river, appears to be a part of 
the ancient river bed, representing a stage marked farther to the south 
by a well developed terrace. This portion of the channel is separated 
from the main river gorge by a moderate rise of sufficient elevation to 
form a considerable island in the river during that stage. 
2. The next attempt at cutting a channel outside the present one is 
found in sections 24 and 25 of T. 34 N., R. 19 W. This is in the north- 
ern part of the village of Taylor's Falls. The exact location is in the S. 
E. l4 S. E. I4 Sec. 24. and continuing through the E. Ig N. E. I4 Sec. 
25. This marks a stage coincident with the 780-foot terrace, and is in 
itself cut down nearly to the 760-foot contour line. At this stage of the 
river the rock outcrop lying in the S. W. I4 S. W. I4 Sec. 19., T. 34 N., 
R. 18 W., formed a bare, rocky island in the stream, reaching an eleva- 
tion of 800 feet. 
3. The third channel, and the most extensive and important one with- 
in the limits of the district, extends from the elbow in the Dalles, S. W. 
I4 S. W. I4 Sec. .30, T. .34 N., R. 18 W., thnuigh the W. i^ N. W. I4 
Sec. 31, T. 34 N., R. 18 W., and S. E. I4 Sec. 3(;. T. 34 W., R. 19 W., 
\n the river at Folsoni lake in N. W. I4 Sec. 1, T. .'13 N., R. 19 W. 
