23 



An examination of the minerals in the third foot-section on the 

 two drifts showed that on the Kansan considerahly larger quantities oi 

 trap rocks and iron minerals (limonite, magnetite, etc.) were present 

 than on the Late Wisconsin, while on the latter a higher percentage of 

 quartz, light colored quartzite, chert and shales was observed, no trace 

 of the two last named rocks being found on the Kansan. 



The average weight of the gravel particles (Table 10 j in the three 

 foot section is very similar for all fields on the Late Wisconsin and for 

 Fields IV and V on the Kansan. The average weight for the other 

 fields, I, II and III, on the latter, is slightly higher, due to the heavier 

 particles found in the third foot-section. 



Table 10. — Averai^e iveight of eoarse gravel particles in the different sections 

 from the five fields on Carrington loam. 



