64 THE DEVONIAN AND CARBONIFEROUS. Ibull.80. 



garded them as representing both the Marcellus and the Hamilton, 

 although not equivalent to either. 1 



In 1843 2 JJavid Dale Uwen commented u On the Geology of the West- 

 ern States.' 7 In this paper a fine-grained sandstone and chert with 

 iron ore was described from Tennessee, Kentucky, and Indiana, and 

 examined on its outcrop near the Knobs. In its lower part this forma- 

 tion was correlated with the Devonian system of England and with the 

 Chemung group of New York, and was described as resting on black 

 bituminous shales and as equivalent to the Marcellus shales of New 

 York. 



The high appreciation of the results of the New York State survey is 

 indicated by the frequent references which were made in the Journals 

 to the reports. 3 



In D. D. Owen's review a tentative scheme of a chronologic table is 

 given as follows: 4 



I'rotozoic rocks or New York system. 



Transition series I. Potsdam sandstone. 



f 2. Calciferons sandrock. 

 '.i. Black River limestone. 



First or Lower Division { 4. Trenton limestone. 



5. Utica slate. 



I 6. Hudson River group. 



( 7. Oneida Conglomerate. 

 Transition series <? 8. Medina sandstone. 



( 9. Clinton group. 



f 10. Niagara sandstone. 



| 11. Onondaga .Salt group. 

 Second or Middle Division .. { 1*2. Water limestone. 



13. Fentamerus limestone and Cat-skill shaly limestone. 

 • v 14. Oriskany sandstone. 

 i 15. Cauda-galli and Schoharie grit. 



Transition series <? 16. Onondaga limestone. 



( 17. Corniferous limestone. 

 1 8. Marcellus shale. 

 lit. Hamilton group. 

 ■J<». (;<;uesee slate. 

 „21. Portage group. 

 Transition-series 22. Chemung group. 



Third or upper division < 



Owen speaks of the Marcellus shale as "the base of the third division 

 of the American Protozoic rocks." The equivalents to this are given 

 as the " lower part of F. VIII of Pennsylvania and Virginia, Post- 

 medidial, Older Black slate of Bogers." 5 The transition from the under 

 lying Corniferous and Seneca limestone is sharp. 



He expressed the opinion that the black shale at the Falls of Ohio is 

 probably the representative of the Genesee, and that the Eucrinital 

 limestone of Tennessee and Kentucky (Button Mould Knob) may rep- 

 resent the Eucrinital limestone of the Hamilton of New York. 6 



•See Am. Jour. Sci., vol. 43, pp. 161-162. 



2 Am. Jour. Sci., vol. 45, pp. 151-1G5. 



3 Amoug these may be mentioned particularly, " Review of the New York Geological Reports," by 

 D.D.Owen, published in the Am. Jour. Sci, vol.46, pp. 143-157; vol. 47, pp. 354-380; vol.48, pp. 296-316? 

 2d ser., vol. 1, pp. 43-70, vol. 3, pp. 164-171. 



4 Ibid., vol. 47, p. 355. (This article is signed "D. D. O.," p. 380.) 

 6 Am. Jour. Sci., voL 3, 1847, p. 57. 

 6 Ibid, p. 72. 



