590 



IOWA ACADEMY OF SCIENCE Vol. XXV, 1918 



hontas counties. In spite of the softness of the Cretaceous rocks 

 fossils certainly could be transported as far as the gypsum region 

 and in fact they are found in the drift at considerable distances 

 from the original strata. There are no known strata in north- 

 western Iowa west of Webster county intermediate in age be- 

 tween the Missouri and the Cretaceous. The presence of Mis- 

 souri life forms in the conglomerate of the gj^psum region proves 

 it to be of post-]\Iissouri age. while the entire absence of fossils 

 of Cretaceous or later age argues strongly for a post-^Ossouri- 

 pre-Cretaceous age for the 'Conglomerate and for the associated 



Fig. 197. — A view from the opposite end of tlie pit, Vincent pit, showing' 

 the uneven surface. 



gypsum and the shales and sandstones which in some localities 

 ■overlie it. The po.s.sibility of the Miocene age of these beds, 

 which has recently been advanced,- seems to be definitely ex- 

 cluded by the evidence. 



Doctor Sidney L. Gralpin of the Department of Geology of 

 Iowa State College informs the writer that a similar fossiliferous 

 conglomerate underlies the gypsum beds of Kansas, which are 

 well known to be of Permian age. 



, Vol. XXI, p. 186. 



^Keyes. Clias.. Iowa Acad 

 100, p. 466, 1915. 



Eng. & Min. Jour.. Vol. 



