134: GEOLOGY OF EASTERN WISCONSIN. 



reason to believe that the original surface of the drift, which controlled 

 the direction of the stream, was determined by these underlying 

 formations, and that they are none the less truly, though remote- 

 ly, the governing influences. This view of the case is supported by 

 the unquestionable facts relating to the similar detour, though 

 in an opposite direction, of the Peshtigo river at a point nearly op- 

 posite. 



Although perhaps more than usually winding in its minor features, 

 the general course of the Peshtigo river is exceptionally direct, and 

 almost exactly southeast. The only noteworthy deviation is that to 

 which attention is now called. From the outlet of Lake l^oqueba, its 

 course is nearly due south until it crosses the western edge of the 

 Lower Magnesian limestone near the third correction line, when it 

 immediately sweeps round to the north of east, and flows nearly at 

 right angles to its general course for about nine miles, approaching 

 the Menomonee within less than three miles, when it reverts to its 

 southeastward course. 



Throughout this northeasterly course, it is flanked on the south- 

 east by a wall of Trenton limestone and St. Peters sandstone, the for- 

 mer appearing at points in naked ledges left projecting by the disin- 

 tegration of the latter. The present bed of the stream is excavated 

 below the horizon of these formations, and lies in a trough cut from 

 the Lower Magnesian limestone, for the greater distance. But the 

 dip of the formations to the eastward is greater than the descent of 

 the stream, so that it is finally enabled to surmo.unt them at Potato 

 and White rapids, when it returns to its original direction. 



The controlling influence of this barrier is also shown to the south- 

 ward in the courses of the "Little river" of the Peshtigo, and the 

 "Little river " of the Oconto. 



Perhaps the conjecture may be ventured that the Peshtigo and Me- 

 nomonee rivers, before the drift period, united near their point of 

 nearest approach on the west side of this limestone barrier, and passed 

 it through a common, but now drift-filled and concealed, channel, for 

 it is abundantly evident that they did not then pass it, at the same 

 points they now do, and this vicinity appears to present the lowest 

 point to which the western edge of the Trenton limestone is depressed 

 within the basin of these rivers. 



On the flats below the village of Peshtigo, the tortuous course of 

 the river reminds us of the Asiatic Meander. 



If the limitations of our space allowed us to go more into detail, 

 and to examine the minor streams, we should find equally instructive, 

 though less conspicuous, phenomena. "We can find room for only one 



