616 IOWA ACADEMY OF SCIENCE Vol. XXV, 1918 



side of the river, about five miles above Fort Dodge. Two 

 small outcrops were seen here, one near the mouth of the creek, 

 the other about two hundred feet upstream. The lower exposure 

 shows about two feet of gray nodular concretionary calcareous 

 marl, under which is exposed a few inches of sandy shale. At 

 the upper outcrop there is exposed above water a foot of gray- 

 green, red and varicolored clay shale, similar to those on Lizard 

 creek. A few specimens of Spirifer pellaensis Weller and 

 Fugnoides ottumwa (White) M^ere found in the clay shale. 



Along the west forlv of Des Moines river aljove Humboldt 

 there are several outcrops of brightly colored clay shales which 

 resemble those along Lizard creek although since they are non- 

 fossiliferous the identification must rest on lithological similari- 

 ties alone, and is not positive. 



In the banks of a little brook, just above bridge 355 on the 

 Chicago and North Western railway, about one-haJf mile east 

 of Rutland, there is exposed two feet of bright red clay shale 

 which is very finely arenaceous and breaks with a coarsely 

 starchlike fracture. It is at the level of the Des Moines flood 

 plain and reseanbles the red shale below the Minneapolis and 

 St. Louis Railroad bridge over North Lizard in Webster county. 

 Between Rutland and Bradgate there are exposures of red and 

 blue-gray clay shales as follows : In the bed of the small creek 

 jast back of the creamery at Rutland; about a mile above the 

 Rutland bridge, on the south side of the river, rising eight to 

 ten feet above the water; in the south bank of the river in the 

 southeast quarter of section 15 ; in the northeast quarter of sec- 

 tion 23 ; and just below the Bradgate bridge. It is difficult to 

 determine whether these shales are Ste. Genevieve or Fort 

 Dodge although on account of their clayey nature the former 

 possibility seems the more probable one. 



Further examinations of the outcrops near Minneapolis and 

 St. Louis Railroad bridge over North Lizard creek show that the 

 clay shales are exposed in a small gully for at least thirty 

 feet above the stream. This is perhaps two hundred feet be- 

 low the tributary ravine mentioned on page 601. Along this 

 ravine to the north there are exposed at intervals for nearly 

 one-half mile pink and gray clay shales which rise at least 

 twenty feet above the water. Just north of the east-west road 

 crossing the center of section 8 is a ledge of fine gray sandstone 

 ten feet high. Over it lies ten feet of red sandy shale Avith 

 some sandstone layers. The relations here seem to be cumula- 

 tive proof for the theory that these shales belong to the Ste. 

 Genevieve. 



