12 CHARLES S. PROSSER 



from the underlying Coal Measures by the absence of coal and 

 black shales, and by the prevailing magnesian character of its 

 limestones, by the presence of certain characteristic indurated 

 marls and oolitic limestone, as well as by the new and distinct 

 types of animal life." ' These rocks are undoubtedly of Permian 

 age and it is probable that the Neosho formation and possibly a 

 part of the Chase occurs in Gage county. This supposition is 

 supported by the statement of Professor Knerr that in Marshall 

 county, Kansas, which adjoins Gage county on the south, there 

 are about 250 feet of Permian above the Cottonwood lime- 

 stone.^ 



OTOE COUNTY. 

 HISTORIC REVIEW OF THE GEOLOGY OF THE COUNTY. 



To the north of Nemaha and Johnson counties is Otoe county 

 which extends from the Missouri River on the east to Lancas- 

 ter county on the west. This is an important county in the 

 history of the geology of southeastern Nebraska because the 

 cliffs near Nebraska City have been fully described by several 

 geologists. 



Owen in 1852 gave some account of the rocks along this 

 part of the Missouri River, referring them to the Carboniferous. 

 He briefly described the rocks in the bluff near Fort Kearney 

 (the old name for Nebraska City) and reported Productus costatiis, 

 P. Flemingii = P. corn, and Fusulina cylindrica, which he says 

 "previous to this discovery was only known in Ohio." 3 



Swallow in 1855 mentions strata at Fort Kearney and the 

 mouth of the Little Nemaha which he referred to the "Upper 

 Coal Series " of the Upper Carboniferous. ^ 



In 1855 Marcou published a geological map of the United 

 States on which the rocks along the Missouri River from the 

 mouth of the Big Sioux to that of the Kansas River are colored 



'Am. Naturalist, Vol. XX, p. 882. 

 ^Univ. Geol. Sur. Kansas, Vol. I, p. 144. 



3 Rep. Geol. Sur. Wisconsin, Iowa and Minnesota, pp. 133, 134. See sections 

 34 and 35 M. 



■* 1st. and 2d. Ann. Rep. Geol. Sur. Missouri, p. 79. 



