42 2 WALTER H. SCHOEWE 



Creek flowing north and Brophy Creek south, and in both cases, 

 the creeks are very small in proportion to the size of the valley. 

 The valley occupied by one stream continues across the very gentle 

 divide at its head into that of the other without any constriction 

 or in any way losing its identity. The divide between the two 

 creeks, which has an elevation of about 670 feet above sea level, 

 is so flat and poorly drained that a large marsh, formerly Goose 

 Lake, covers its surface. Were it not for the fact that the creeks 

 are seen to flow in opposite directions a divide would not be sus- 

 pected. 



Exposures in the channel are extremely few and those seen 

 consist chiefly of horizontally stratified sand covered by loess. 

 According to Carman, 



The surface material of Goose Lake valley passes downward into fine sand 

 which is 60 to 100 feet thick on the divide south of Goose Lake. Farther north 

 in Sees. 17, 8 and 5 of Deep Creek Township, Clinton County, several wells 

 go no to 120 feet in sand and fine gravel. In the south part of the channel 

 south of Elvira, wells 70 to 80 feet deep do not reach rock.' 



MUD-ELKHORN-MUD CREEK VALLEY 



For a distance of about fifteen miles westward from the south 

 end of Goose Lake channel the temporary Mississippi River followed 

 the valley of Wapsipinicon River to the debouchure of Mud Creek. 

 This portion of the valley bears no particular name and calls for 

 no special comment. 



The name Mud-Elkhorn-Mud Creek Valley is applied to that 

 part of the temporary Mississippi River course which lies between 

 the mouth of Mud Creek on the north and the junction of Elkhorn- 

 Mud Creek and Cedar River on the south, a distance of approxi- 

 mately thirty-six miles (Fig. i). Like the Goose Lake channel, 

 this valley also contains two insignificant streams, one flowing to 

 the north and the other to the south. As the divide between the 

 creeks in the Goose Lake channel is imperceptible and ill drained, 

 so is that between the headwaters of Mud and Elkhorn creeks in 

 the Mud-Elkhorn-Mud Creek Vafley. Several large ponds and 

 marshes cover its surface. It has an elevation of about 725 feet 



'J. Ernest Carman, "The Mississippi Valley between Savanna and Davenport," 

 Illinois Geol. Survey, Bull, ij (1909), p. 57. 



