558 



IOWA ACADEMY OF SCIENCE Vol. XXV, 1918 



The relations of the present Des Moines valley and the ancient 

 Moingona gorge at Des Moines are shown below (figure 180). 



That such a great drift-filled channel is traceable entirely 

 across our state is made largely possible through the results and 

 records obtained by our State Geological Survey. Although its 

 determination appears at first glance a strictly scientific achieve- 

 ment it is not "v\athout important economic bearings. Artesian 



Fig. 179. — Sketch map of Lee county showing courses of old Mississippi 

 and old Moingona rivers. 



waters derived from Glacial gravels doubtless mark the entire 

 •course of the ancient valley, as they are already encountered in 

 some parts. Local reservoirs of natural gas occur in the old 

 valley. The gas-wells of Ilerndon, in Guthrie county, are of 

 this class. Systematic prospecting along the line of the buried 

 valley probably will reveal other similar pockets. 



Another point of especial local economic interest is the pres- 

 ence of an immense gravel bed in the old gorge at Des IMoines. 



