Conodonts from isolated Devonian outcrops

Abstract

Shales, sandy shales, and sandstones were sampled from isolated outcrops at Sulphur Springs and at Coal Hollow in Ste. Genevieve County. An attempt was made to find the answers to the following questions: (1) Can the boundary between the Devonian and the Mississippian be located at these localities by determining the distribution of conodonts? (2) Are there faunal difference between the concodonts in the Devonian part of the section? (3) Are there differences between the conodonts of the sandstones and the sandy shales that may be interpreted as environmental responses? (4) What other formation or formations do the conodonts of these two Devonian sections or parts of these sections suggest as time equivalents? It was concluded the boundary can be located in each of these localities. It was also concluded that there are no faunal differences in the Devonian part of the Ste. Genevieve County section or between the sandstones and shales that could not be interpreted as the result of factors which could not be controlled in the present study. Other formations or sections suggested as time equivalents to the Ste. Genevieve County section are the sandstone facies of the Eureka shale, the Sees Creek section, and the "Grassy Creek" group, as defined in this paper. Owing to the lack of conodonts in the Sulpur Springs samples, no similar conclusions were drawn concerning this locality.