62 THE DEVONIAN AND CARBONIFEROUS. ^bull.80. 



Old Red in Forfarshire, etc., Scotland, in its gra£, thin, laminated sand- 

 stones and green shales," Hall recognized in Ohio, at Cuyahoga Falls, 

 Akron, etc. He also correlated the Portage and Gardeau with rocks at 

 Cuyahoga Falls and Newburg in Ohio, but found thein of diminished 

 thickness. He said, "The Portage sandstone (known as Waverly 

 sandstone) n is found in many places in Ohio. The thin-bedded lime- 

 stones which he found often Oolitic in structure, and in some places 

 becoming thick beds of limestone interstratified with sandstone, in 

 Indiana, Illinois, and Kentucky, Hall found to contain fossils which 

 were different from those of the limestones of New York, and he thought 

 them to be identical with the Carboniferous limestone of Europe, re- 

 cording one of the fossils, Productus hemispherlca, which was a char- 

 acteristic of that formation. 1 The conglomerates which occur above 

 this he correlated with the Millstone grit of the British classification. 

 This identification of the carboniferous rocks in the West, or in the 

 Mississippi Valley Basin, was not new with Hall, but had been made 

 several years before by D. D. Owen, as will be shown further on. 



In 1842 Hall 2 read a paper before the Association of Geologists and 

 Naturalists, which was published the following year with a plate ex- 

 plaining a section from Cleveland to the Mississippi River. In this 

 plate the Waverly sandstone series of the Ohio report is called " Che- 

 mung and Portage groups." The term " Subcarboniferous rocks" is 

 applied to " friable gray sandstone with intercalated beds of oolitic 

 limestone" lying between the " Waverly series" and the " Carbonifer- 

 ous limestone." Where the latter outcrops in the Mississippi River 

 Valley it is called the " Great Carboniferous limestone." 



At Newburg " the Portage sandstone or upper part of the group is 

 seen, and is there underlaid by the green shale. These are equivalent 

 to the Waverly sandstone of the Ohio reports, as was afterward ascer- 

 tained by visiting the quarries at Waverly. From New burg we pass 

 over the shales and sandstones of the Chemung group, till we arrive 

 upou the Conglomerate, which is well developed at Stow and Cuyahoga 

 Falls. This Conglomerate, which, so far as I could discover, is identi- 

 cal with the outlier of a similar mass in the southern part of New York, 

 is the fundamental rock of the great coal formations." 



The " black, bituminous shale underlies this Portage and Chemung 

 on the road toward Columbus, and represents Hamilton and Marceilus, 

 particularly the latter." 3 



In the vicinity of Louisville and New Albany, at the Falls of Ohio, 

 the " black, bituminous limestone " he correlated with the Marceilus 

 shale of New York above the " Corniferous limestone." This is fol- 

 lowed by the "green shales and slaty sandstones of the Portage group 



1 Notes upon the Geology of the Western States, Am. Jonr. Sci., vol. 42, p. 57. 



2 Hall, James : Notes explanatory of a section from Cleveland, Ohio, to the Mississippi River, in a 

 southwest direction, with remarks upon the identity of the western formations with those of New 

 York. Assoc. Am.Geol., Trans., 1843, pp. 474-531, 



3 Ibid.,p.272. 



