1881.J ^Od [Stevenson. 



that group and of the upper part of the Knox group can be obtained in 

 passing from Clinch mountain through Estillville and thence towards Cop- 

 per creek, by either the Rye Cove or the Stony Creek road. The liigher 

 beds of the following section were seen on the former road, while the lower 

 beds were examined on the latter. There may be an error in No. 15, for 

 that is the horizon at which the two sections were joined, and the thick- 

 ness of that mass may be greater than is given. All thicknesses are based 

 on estimates, the dip being such that instrumental measurement is neces- 

 sary for accurate determinations : 



Trenton and Naslwille Group. 



1. Shale and thin limestone 600' 



2. Limestone and calcareous shale 25' 



3. Calcareous shale 130' 



4. Limestone 70' 



5. Shale 65' 



6. Limestone 45' 



7. Shale 50' 



8. Massive limestones 200' 



Knox Group. 



9 . Cherty rock and limestone 160' 



10. Limestone and shale 120' 



11. Concealed 60' 



12. Cherty rock 165' 



13. Light blue limestone 55' 



14. Concealed 15' 



15. Limestone, shale and chert beds 300' 



16. Variegated shale 70' 



17. Limestone 250' 



18. Shale 60' 



19. Limestone 260' 



20. Shale 30' 



21. Silicious limestone 200' 



Total, Trenton and Nashville, 1185' ; Knox group exposed, 1745' 



No. 21 is exposed along Copper creek, and is the rock which, in this 

 memoir, has been regarded as marking the base of the upper division of the 

 Knox group. The dip throughout Moccasin ridge is not far from 30 de- 

 grees, but the rate increases on Clinch mountain, that at the base of No. 3 

 being 42 degrees. 



No continuous exposure of the shales, No. 1, was seen ; but, as far as 

 observed here, the features are the same as on the northerly side of 

 Wallen's ridge. Thin limestones were seen, several of which are fossil- 

 iferous. No. 2 is well shown on the side of Clinch mountain at the residence 

 of Mr. R. A. Ayres, opposite the village of Estillville, where it consists 

 of limestone, 2' ; calcareous shale, 10' ; ferruginous shale, 5' ; limestone, 

 8'. The upper limestone is impure, irregularly bedded, and contains a few 



