106 IOWA ACADEMY OF SCIENCES. 



4. Specimen of the Clower phase taken from the quarry 

 at Mount Vernon. Analyzed by Mr. E. A. liayner. 



CaCOs 54.02 per cent. 



MgCOs 44.73 



FeeOs and AhOs 0.61 



SlOs 0.-29 



Total !»1).05 



The rock is nearly a typical dolomite. 



5. The rock at the Palisades on the Cedar river, six 

 miles distant from Mount Vernon, is similar in composi- 

 tion to the Mount Vernon Rock. It is stratified, but not 

 granular. Building stone occupies layers adjacent to 

 others which are burned for lime. The specimen was 

 analyzed by G. R. Greaves. 



CaCOs 53.64 per cent. 



MgCOs 43.89 per cent. 



Ve-.Os and AhOs 0.52 



SiOa 1.98 



Total 100.03 per cent. 



6. This is of the same type as 3. It is a finely lam- 

 inated building stone, but crystalline instead of granular. 

 The specimen analyzed by Miss Herrinton is from the 

 large quarries at Lime City. It is nearly a dolomite in 

 compostion. 



CaCOs 55.3 per cent. 



MgC03 43.0 



FezOsand AI2O3 1.4 



SiOe 0.6 



'J'otal 100.3 per cent. 



7. This is also a representative of the Gower limestone 

 and of the LeClaire lithological phase. The specimen was 

 taken from a ledge on Rock creek, two and a half miles 

 southwest of Tipton. The ledge is notable for its excep- 

 tionally high dip, reaching 70 = . It varies but little from 

 a true dolomite. The analysis was made by G. R. Greaves. 



CaCOs 55.76 per cent. 



MgCOs , 43.85 



