■ GEOGRAPHICAL CHANGES DURING PENNSYLVANIAN 143 



That all but an insignificant part of the Appalachian basin had be- 

 come dry land at the beginning of the Pennsylvanian was suspected long 

 ago. In 1874 Professor Newberry * thought that some of the West Vir- 

 ginia coal beds were older than the Ohio conglomerate, and in the follow- 

 ing year Professor Andrews f asserted respecting certain plants obtained 

 at the bottom of the Ohio column that "their stratigraphical position 

 is more than 2,000 feet above the base of the series as revealed in the 

 geosynclinal basin of West Virginia, which was first filled with strata 

 of the Coal Measures before any similar formations took place upon the 

 ancient marginal Waverly plateau of Ohio." A year later Mr Maury,! 

 making use of measurements by Professors W. B. Eogers and W. M. 

 Fontaine, called attention to the great difference in extent of the deposits 

 in the northern and southern parts of the basin; but the erroneous con- 

 ceptions concerning correlation then prevailing prevented him from 

 recognizing the full value of his data. Fifteen years afterward Doctor 

 White § compared the Ohio and Pennsylvania Pottsville with that of 

 West Virginia and indicated the vast thiclcness in West Virginia of 

 rocks below the Jackson Shaft coal horizon of Ohio, illustrating his 

 understanding of the relations by a diagram. In the interim Mr Les- 

 quereux j| had tabulated the distribution of plants obtained from Penn- 

 sylvania and had shown the existence of horizons in Tennessee below those 

 of Ohio, and had compared the lower horizons with those in the anthra- 

 cite region of Pennsylvania. It was reserved for Mr David White, after 

 study of fossil plants collected systematically in many portions of the 

 basin, to present the conclusion in definite form and to determine the 

 relation of the earlier anthracite deposits to deposits in other parts of 

 the great area.lf His studies, based primarily upon paleontology, led 

 to practically the same conclusions with those reached by the writer 

 from study of stratigraphy and presented in the following pages. The 

 two lines of investigation have not led in all cases to full agreement 

 in correlation, but it must be conceded that the disagreements are con- 

 fined mostly to localities where the stratigraphical evidence is incom- 

 plete. 



At the beginning of the Pennsylvanian the water area was confined 

 to lakes on the eastern side of the basin, one in northeastern Pennsyl- 



• J. S. Newberry : Geology of Oliio, vol. li, 1875, p. 167. 



t B. B. Andrews : Palseontology of Ohio, vol. ii, 1875, p. 415. 



t M. F. Maury, Jr. : Resources of West Virginia, 1876, p. 187. 



§ I. C. White : U. S. Geol. Survey Bulletin, no. 65, 1891, p. 182. 



II L. Lesquereux : Coal flora of the Carboniferous formation of Pennsylvania and 

 throughout the United States, 1880, pp. 636 et seq. 



H D. White : Deposition of the Appalachian Pottsville. Bull. Geol. Soc. Am., vol. 15, 

 1905, pp. 267 to 282, and map. 



