88 GEOLOaiCAL FORMATIONS. 



are thought to represent the Eocene consist chiefly of brown 

 sands and blue clays, with some iron ores. The best exposures 

 are found in the bluffs of the Mississippi in Scott and Stod- 

 dard counties. 



PLIESTOCENE, 

 The drift mantle extends from the northern boundary of 

 the state southward as far as the Missouri river approximately. 

 These deposits consist mainly of silts, sands and boulder clays, 

 incoherent and indiscriminately mixed. 



