88 KANSAS ACADEMY OF SCIENCE. 



on the character of the strata being eroded. Hence there might be 

 all gradations from gypsiferous shales to pure gypsum. At some 

 time the limestone might not, have been changed to gypsum and beds 

 of limestone, dolomite or calciferous sandstone would be formed, 

 mixed or interstratified with clay. 



