CARBOA'IFEROUS AND PERMIAN FORMA TIONS I 5 



In 1868 Professor Marcou reaffirmed the Dyassic age of the 

 Nebraska City rocks, stating that: "In Nebraska the Dyassic 

 rocks form the right bank of the Missouri River from Aspinwall 

 to Plattesmouth and Aureopolis, that is to say, all the bluffs of 

 the counties of Nemaha, Otoe, and Cass The best sec- 

 tion of the Dyas of Nebraska and the most easy to be studied, 

 is that formed by the bluff at the Nebraska City landing, at Otoe 

 City, at Peru, and at Brownville, where the strata are higher in 

 the Dyassic series than at Nebraska City ; whilst at Rock Bluff, 

 Plattesmouth, and Aureopolis, on the contrary, we find the lower 

 layers forming the base of the Nebraska Dyas." ^ Following 

 the above is a detailed section of the rocks at the Nebraska City 

 landing accompanied by lists of fossils which were identified by 

 Professor H. B. Geinitz. In 1892 Professor Marcou still regarded 

 the Nebraska City rocks as of Lower Dyassic age.- 



In the summer of 1867 Meek and Hayden spent about two 

 months in carefully studying the rocks along the Missouri River 

 from Omaha to Kansas. In 1872 an excellent work based upon 

 this study was published in which Hayden discussed the general 

 geology of southeastern Nebraska, and Meek gave a detailed 

 account of the stratigraphy of the Missouri River region accom- 

 panied by a very careful description of the fossils. 3 This work 

 has become a classic in paljEontology for the Upper Carbonifer- 

 ous of the Mississippi Valley. The conclusion in reference to 

 the age of these Missouri River beds agrees with the former 

 opinion of Meek and is clearly expressed in the following sen- 

 tences : "From all of the facts, therefore, now determined, it 

 must, I think, be clearly evident that all of these strata under 

 consideration along the Missouri, that have been by some 

 referred in part to the Mountain limestone, in part to the Per- 

 mian or Dyas, and in part to the Coal Measures, really belong 

 entirely to the true Coal Measures ; unless the division C, at 



'Trans. Acad. Sci., St. Louis, Vol. II, p. 562. 

 'Am. Geol., Vol. X, pp. 369, 373. 



3Final Rep. U. S. Geo. Sur. Nebraska and portions of the adjacent Territories, pp 

 245, 11 plates. 



