FIELD INVESTIGATIONS IN 1 92 1 827 



in tracing the formation along the bluffs from the old Government 

 quarry, 2 miles above Sainte Genevieve, to the south side of Aux Vases 

 River; approximately 5 miles below the town. In the quarry the more 

 or less oolitic lower part of the formation shows extraordinarily well 

 developed cross-bedding for a limestone. This part is succeeded by about 

 30 feet of yellowish gray, sanely-textured limestone which I regard as 

 including the horizon of the Eosiclare sandstone of the sections in Hardin 

 County, Illinois, and western Kentucky. Over this to the base of the 

 mantle of loess is slightly sandy and shaly limestone with fossils, the 

 most conspicuous of which is a very large and apparently undescribed 

 species of Bellerophon, found only at this place. 



Going southward from this quarry the cross-bedding of the lower beds, 

 evidently a near-shore facies, changes to horizontal bedding. This pre- 

 vails in the shallow syncline in which the town of Sainte Genevieve is 

 located. But cross-bedding prevails again in the succeeding low anti- 

 cline that elevates the unconformable top of the Saint Louis to some 8 or 

 10 feet above the level of the highway in the bluffs iy 2 to 2% miles south 

 of the town. Here also the sandy character of the higher beds of the 

 Sainte Genevieve is developed in thickness and volume of siliceous con- 

 tent about as in the Government quarry 4 miles to the north. Proceeding 

 from this point to the south side of Aux Yases Eiver, the road crosses 

 another shallow syncline, in the southern half of which the typical ex- 

 posure of the overlying Aux Vases sandstone occurs in the abandoned 

 Richardson's quarry, out of which the rock used in the construction of 

 the Eads bridge at Saint Louis was procured. 



The section shown in the column on the left of the chart was compiled 

 by Mr. Butts and myself from exposures on the two sides of the Aux 

 Vases found along the highway and in near-by places to the east and 

 west. The Cypress sandstone probably does not occur here, and only the 

 lower part of the Paint Creek formation is clearly visible. However, the 

 beds that are most important in this connection, namely, those referred 

 to the Yankeetown, Renault, Aux Vases, and Sainte Genevieve forma- 

 tions, are sufficiently well exposed and characteristic to leave no question 

 as to their character, fossil contents, and stratigraphic relations. 



Going downward in this section we may begin with the 10-foot bed of 

 highly siliceous sandy limestone that Weller, Butts, and I are agreed on 

 in correlating with the Yankeetown of Randolph and Monroe counties, 

 in Illinois. Under this is a variable bed of 30 to 35 feet in thickness, con- 

 sisting mainly of more or less highly fossiliferous limestone, but includ- 

 ing layers of shale, sandstone, and conglomerate. Concerning this also 

 we have agreed in calling it Renault. The Renault rests on the Aux 



