578 P. E. RAYMOND TRENTON OF TENNESSEE AND KENTUCKY 



14. Rather thinly bedded strata which weather to a rubbly mass— 30 feet. 



15. Less shaly beds with a layer of large Stromatoceria and Columnaria at 



the base — 12 feet. 



16. A layer of much contorted limestone suggesting slumping. Rolled effect 



particularly well shown — 10 inches. 



17. Limestone like 13 — 7 feet. This is the highest exposure near the station 



of the Tennessee Central Railroad. 



Correlation with Kentucky 



About 7 feet above the base of zone 13 one finds the typical Catheys 

 fossils, such as Cyclonema varicosum and Constellaria emaciata; so that a 

 part at least of the Catheys is to be considered as of the same age as the 

 Cynthiana. The layer of Stromatocerium at the base of number 15 is 

 probably not the "Sponge bed" of Jones' paper, since it lies 37 feet above 

 the "False Dove." Jones stated that the Sponge bed rested in some places 

 directly on the False Dove, whereas in others it was separated from it by 

 from 10 to 15 feet of ordinary blue limestone. 10 He mentioned another 

 occurrence of Stromatocerium as much as 25 feet above the Sponge bed, 

 and it is probable that it is this higher layer which was encountered in 

 the above section. Jones attached considerable importance to the Sponge 

 bed, considering its top the upper limit of the Trenton. If there is more 

 than one such stratum, as there apparently is, a bed of Stromatocerium 

 will prove a very unreliable indicator of the plane of separation of two 

 formations. 



The abundance of Bellerophon troosti and other gastropods in the 

 Cyrtodonta bed (number 11), and particularly its association with a 

 "Birdseye" limestone (number 12), justify its correlation with the Faul- 

 coner, and the False Dove with the Salvisa, these two representing the 

 Perry ville. Whether or not the lower part of number 13 is the Cornish - 

 ville has not been determined. 



The Ward limestone is, according to Jones, fairly fossiliferous, and it 

 is significant that in it is the lowest horizon at which Columnaria alveolata 

 is found. He also lists Orthis borealis (Heoertella frankfortensis) and 

 Rhynclionella fringilla (probably Orthorhynchula linneyi). These fos- 

 sils strongly suggest a correlation with the Woodburn of Kentucky. It 

 may also be noted that these are the only strata in the section which pro- 

 duce chert, and since that is a unique characteristic of the Brannon in 

 Kentucky it is entirely possible that the Ward represents both the Bran- 

 non and the Woodburn. At Columbia, according to Hayes and Ulrich, 



10 Loc. cit., p. 45. 



