222 



A. Winsloiv — Cambrian in Missouri. 



nesian series is necessary,* and it is further tending to the con- 

 clusion that rocks placed higher in the series than the Third 

 sandstone are of Cambrian age. As bearing upon these ques- 

 tions the results of studies recently made by the writer in 

 Madison, St. Francois and Ste. Genevieve counties are here 

 presented. 



Fig. 1. — Outline map of St. Genevieve, St. Francois and Madison Counties. 



Previous Results in St. Genevieve County. — St. Genevieve 

 county is in the eastern portion of the State, about 40 miles 

 south of St. Louis. As is shown in the adjoining sketch it is 

 bordered by the Mississippi river on the east, by St. Francois 



* Vol. ii, Report Missouri Geological Survey, 1892 ; Iron Ores, chap. v. 



