50 GROLOGICAL FORMATIONS 



In 1858 Hall continued to regard the Burlington (Iowa) 

 section below the oolite layer as Chemung. But he also in- 

 cluded in the group some yellow sandstones occurring fifty 

 miles to the northward, which Calvin* has recently proved con- 

 clusively to be of Devonian age. 



Although Owen had referred the shales lying immediately 

 below the limestone at Burlington, Iowa, to the Subcarbon- 

 iferous (limited ) more than a decade previously. Meek and 

 Worthen f in 18(31 were the first to prove beyond a doubt that 

 the faunas of the rocks along the. Mississippi river between 

 the cities of Burlington and Saint Louis, and lying between the 

 " black shales " and the Burlington limestone, have much closer 

 affinities with those of the overlying strata than with those 

 below, and therefore the rocks in question properly belong to 

 the Lower Carboniferous series. The name •' Kinderhook " was 

 then proposed for the formation. 



Soon after, Worthen | published further details, especially 

 in regard to the typical locality, Kinderhook, Illinois. Various 

 sections in the neighborhood were fully described, leaving no 

 doubt as to the exact limits that were intjBnded to be assigned 

 to the formation. On the opposite side of the river, in Mis- 

 souri, the exposures are practically continuous for more than 

 30 miles, and show well the relations from the " black shales" 

 to the upper division of the Burlington limestone. 



In the Iowa section, White || recognized as Kinderhook 

 the Burlington rocks previously called Chemung, together with 

 a few feet of what was once considered as belonging to the 

 superimposed stratum. 



The " Chouteau " group takes its name from the leading 

 member of the three-fold division, the Chouteau limestone. 

 The application in this sense was first proposed by Broadhead,§ 

 who used the term to cover the same limits as Swallow's 

 "Chemung" in the earlier Missouri reports. Very recently 



*Am. Geologist, Vol III, p 25. 1889. 

 tAm Jour S(5i., Vol. XXXII, p. 228. 1861. 

 tGeol. Sur. Illinois, Vol. I, p. 108. 1866. 

 IIGeol. of Iowa, Vol. I, p 192. 1870. 

 §Geol. Sur. Missouri, p. 26. 1874. 



