756 



DARRELL H. DAVIS 



a stream emptying into the Detroit River, as shown on the accom- 

 panying map of the vicinity, designed to show the relation of the 

 locahty to the surrounding country. 



Some seventy-five years ago a dam was built across the Middle 

 Rouge near Pikes Peak. Since that time the dam has been main- 

 tained continuously, except that it broke in 1895. It was, however, 

 immediately repaired so that to all intents and purposes the water 

 has been ponded up continuously for about three quarters of a 

 century. 



The floor of the pond is composed of silt of very uniform char- 



CANADA, 



Fig. I. — Map of the vicinity to show the relation of the locality to the surrounding 

 country. 



acter. Deposited under water as it was, and attaining a thickness of 

 several feet, it presented a material of exceptional character for the 

 river to cut into when the water was withdrawn from the surface 

 by the break in the dam. The uniform character of the deposit, so 

 far as any illustration can show it, is shown in Fig. 3, taken about 

 600 ft. above the dam on the right-hand bank of the stream. 



The deposit, which is a fine even clay with absolutely no bowlders 

 or stones, has cracked extensively, and to considerable depths since the 

 withdrawal of the water, and these cracks show plainly in the photo- 

 graph. The vegetation (Polygonum) also shows; but as the picture 

 was taken after snow had fallen, late in November, the luxuriance of 

 its growth is not apparent. 



