ABSTRACTS AND DISCUSSIONS OF PAPERS 157 



The symposium on the Mississippi an controversy was then resumed by 

 the reading of the last paper on the subject, which was illustrated by 

 diagrams; 50 minutes. 



THE CHESTER CONTROVERSY 

 BY E. 0. XJLRICH 



(Abstract) 



The author defended his classification of the Upper Mississippian forma- 

 tions, the sequence, classification, and correlation of the beds of the Chester 

 series in Kentucky and Illinois being discussed in particular. New evidence 

 was presented showing a more decided Chester affiliation of the fauna of the 

 lower as with the upper Sainte Genevieve than had been previously believed. 



Of many stratigrapbic breaks within the Chester series the most widely 

 recognizable, and therefore the most important, is that between the top of the 

 "Tribune" limestone of Caldwell County, Kentucky, and the succeeding typical 

 Cypress sandstone (Bed 1 of Ulrich's Birdsville formation or group). Beneath 

 this break the Chester formation includes two Chester formations — the Sainte 

 Genevieve at the base, the "Tribune" (of Caldwell County) at the top — with 

 a widely distributed sandstone between them. This sandstone is the same as 

 the Aux Vases sandstone of Sainte Genevieve County. Missouri. Following 

 Engelmann and Worthen, who had identified this Lower Chester sandstone in 

 Hardin County, Illinois, with the Cypress sandstone, Ulrich, in his work on 

 the Kentucky-Illinois fluorspar district, adopted the latter instead of the sup- 

 posedly synonymous name Aux Vases sandstone. Now, however, since Weller 

 has shown just what the Cypress sandstone of the type section in Union County, 

 Illinois, is. the term Cypress sandstone, as used by Ulrich in the past (11 

 years), should in every instance be replaced with the name Aux Vases sand- 

 stone. 



The Upper Chester or Birdsville group includes three sandstones — the 

 Cypress, Tar Spring, and Palestine — all generally recognizable in western 

 Kentucky and southern Illinois, and above each a calcareous formation. These 

 Birdsville divisions vary more or less from place to place, and their variations 

 in areal distribution and lithologic character suggests considerable oscillation 

 of the sea in which they were deposited. As a whole, the group contains more 

 sandstone and shale than does the lower or Montesano group. 



The author admitted that the Tribune limestone of the type locality in 

 Crittenden County, Kentucky, is the same as the Menard limestone of Illinois, 

 and hence wholly distinct from the "Tribune" limestone of the adjoining 

 county of Caldwell. On the other hand, he insisted that the latter is a distinct 

 formation, limited below by the top of the Aux Vases sandstone and above by 

 the unconformable base of the Cypress sandstone. The Renault of the Illinois 

 section he regards as representing a part of the same interval. 



The time for adjournment for lunch having arrived, it was decided to 

 postpone the discussion of the three papers relating to the Chester until 

 the afternoon. 



