COOPER LIMESTONE. 



"ONONDAGA LIMESTONE— COOPER MARBLE 



The upper part is a bluish drab compact limestone, con- 

 taining cavities filled with a yellowish green substance, which 

 gives the rock a fine mottled appearance; but it passes down into 

 bluish compact beds, which contain numerous small crystals of 

 calcareous spar. 



Range and Thickness — Its thickness varies from 20 to 60 

 feet, as may be seen in Sec. 17, and the one above from the La 

 Mine, and the following from Clear Creek, some two miles above 

 its mouth: 



No. 1.— 6 feet of Bluff. 



No. 2. — 20 feet of Ferruginous Sandstone. 



No. 3. — 100 feet of Encrinital Limestone. 



No. 4. — 30 feet of Chouteau Limestone. 



No. 5. — 50 feet of Vermicular Sandsone and Shale. 



No. 6. — 30 feet of Lithographic Limestone. 



No. 7.— 20 feet of Cooper Marble. 



It is best developed on Clear Creek, and on the La Mine, 

 between the mouths of Clear Creek and Otter Creek, and on 

 little Saline, in Town. 47, R. 18, Sec. 34*. It becomes much 

 thinner, and passes into dull bluish gray semi-crystalline beds, 

 towards the southern and eastern part of the county, where it 

 is often entirely wanting. 



Organic Remains. — No organic remains have been found in 

 the Cooper Marble proper, but the beds into which it passes 

 to the south and east, contain the characteristic fossils of the 

 Onondaga Limestone." 



In the same report Meek 1 called attention to beds in Moni- 

 teau County that are in part Cooper. "Below the above- 

 mentioned beds, we have at some places in Moniteau County, 

 the lower member of the same group. This rock varies much in 

 its composition, being at some places an arenaceous limestone, 

 and at others a calcareous sandstone, and I even suspect it 

 passes, in some instances, into a pure quartzose sandstone. 



This formation was only met with at the following locali- 

 ties: — First, in a bluff on the Missouri, already referred to. At 



•The writer visited this locality and found Chouteau limestone on St. Peter sandstone 

 and Jefferson City dolomite. 



'Geol. Surv. Mo., Reports I and II, pt. II, pp. 104-105. 



