ITS The American Geologist. September, 1894 
state that the streams crccupy the anticlinals, and the larger 
upland ridges the synclinals. 
As already intimated, the dip between the two secondary 
axes of the area is very slight. But on the south side of the 
southern anticlinal the dip averages 120 feet per mile or 
2.04°. This, however, is not continued far. as the strata soon 
rise into another anticlinal. 
Besides these regular deformations, there are numerous 
local disturbances, the chief of which are small faults. One 
only will be described. This is two and a half miles south- 
west of Foreston, and the exposed portion shows the disloca- 
tion of the St. Peter sandstone and Trenton limestone. The 
strike is northwest to southeast. The dip is about 30° to the 
southwest. The downthrow is on the southwest side (on the 
anticlinal side), and amounts to 40 feet. This small fault is 
noteworthy, from its being the only one in this portion of the 
state where the actual contact can be observed. 
Summary. 
The history of this area, and its features of special inter- 
est, niay be summed up as follows: 
History, (a) Deposition of the Lower Magnesian or Cal- 
ciferous limestone, (b) Probable elevation above sea level 
and erosion of valleys, (c) Existence of a small island lying 
off the southern point of the Isle of Wisconsin. The waves 
beat about this island and over it, forming a thin breccia, 
(d) Deposition of the St. Peter sandstone. The sea in the 
vicinity of the now submerged island was shallow, and at 
times one or more sandy islets may have existed to the west 
of the old island site, as indicated by the irregular stratifica- 
tion, (e) Deepening of the sea and the formation of the 
Buff or Pecatonica limestone, accompanied by a slight eleva- 
tion in the northeastern portion of the area, forming a small 
island, (f ) Slight erosion and slight soil production on this 
island, (g) Decided submergence of the entire region, and 
deposition of the Trenton, Galena. Cincinnati, and Niagara 
strata over it. (h) Last elevation above the sea level, accom- 
panied by the formation of slight anticlinals and many small 
faults, (i) Erosion of the present valleys. 
Features of special interest, (a) The parallelism of the 
Lower Magnesian limestone of Wisconsin and the Elk Horn 
