IOWA ACADEMY OF SCIENCES. 7 



Walker, Peucy H State University, Iowa City. 



Weld, L. G State University, Iowa City. 



Witter, F. M Muscatine. 



ASSOCIATE MEMBERS. 



Ankeny, Miss Nellie W Ottumwa. 



Beardsukar, W. M.. Agricultural College, Ames. 



Hadley. S. M Oskaloosa. 



Howe, Miss Minnie High School, Des Moines. 



Mills, J. S Western College, Toledo . 



OsBORN, B. F .Rippey. 



corresponding members. 



Barbour, E. H State University, Lincoln, Nebraska. 



Bessey, C. E... State University, Lincoln, Nebraska. 



Bruner, H. L Irvington, Indiana. 



Call, R. E Louisville, Kentucky. 



CoLTON, G. H Virginia City, Montana. 



Crozier. a. a Ann Arbor, Michigan. 



Gillette, C. P Agricultural College, Fort Collins, Colorado. 



Halsted, B, D Rutger's College, New Brunswick, N. J . 



Erasmus Haworth State University, Lawrence, Kansas. 



Hitchcock, A. S Agricultural College, Manhattan, Kansas. 



McGee, W. J * U, S. Geol. Survey, Washington, D. C. 



Meek, S. E State University, Fayetteville, Arkansas. 



Parker, H. W New York City, New York. 



Rolfs, P. H Agricultural College, Lake City, Florida. 



Todd, J. E State University, Vermilion, South Dakota. 



WiNSLOW, ARTHUit Gcoi. Survey, Jefferson City, Missouri. 



THE RELATION OF THE CRETACEOUS DEPOSITS OF IOWA TO THE 

 SUB-DIVISIONS OF THE CRETACEOUS PROPOSED 

 BY MEEK AND HAYDEN. 



by 8. CALVIN. 



The cretaceous deposits of Woodbury and Plymouth counties are composed of 

 sandstones, shales and certain calcareous deposits. The heavier beds of sandstone 

 belong to the basal portion of the series, barely rising higher than forty feet above 

 the level of the water in the Big Sioux river. The part of the column to which 

 these heavier sandstones are confined is, however, not all sandstone, but consists 

 of arenaceous beds alternating with beds of argillaceous shales. Above the more 

 massive sandstones the beds, for a vertical distance of fifty to sixty feet, contain 

 streaks and thin layers of sand, but shales preponderate, lu certain typical 

 exposures these alternating beds are followed by from thirty to forty beds of pure 

 shales, dark in color, smooth and unctuous to the feel, and containing the remains 



