410 A. W. GRABAU PALEOZOIC DELTA DEPOSITS OF NORTH AMERICA 



American Association for the Advancement of Science, in connection 

 with the Symposium on Correlation (subsequently published). The 

 validity of this correlation will be more fully discussed in the subsequent 

 pages of this paper. 



THE SOUTHERN SECTIONS 



In eastern Tennessee and adjoining districts of the Virginias on the 

 north and Georgia-Alabama on the south there are two series of deposits, 

 which have as a rule been identified with the "red and white Medina" of 

 Pennsylvania and with the Medina as a whole in New York. The lower 

 of these is a red sandstone and shale resting on "Hudson Biver" (Sevier) 

 shales. From this at various times fossils of Ordovicic types were re- 

 ported, especially by Stevenson, but its correspondence to the Medina as 

 a whole was not questioned, the fossils being regarded as mere relics of 

 an earlier fauna in the higher beds. To this formation the name Bays 

 sandstone was given by Campbell in 1894, 15 who regarded it as "Bed 

 Medina." I believe I was the first to point out that these beds, as well as 

 the Juniata of Pennsylvania and the Lower Medina (Queenston) of New 

 York and Canada, were of the age of the Bichmond of Ohio and Indi- 

 ana 16 , and to furnish evidence for such a correlation. 17 The late Ordo- 

 vicic age of this formation has since been generally accepted, though 

 there is still some difference of opinion as to the precise correlation of 

 these beds. This will be more fully discussed beyond. 



The upper bed or "White Medina" of the southern region was origi- 

 nally named the "Clinch Mountain sandstone" by Safford. 18 Campbell 

 in 1894 renamed it the Clinch sandstone (loc. cit.) and correlated it with 

 the Medina-Oneida. The equivalency of this to the true Medina of New 

 York and to the Oneida conglomerate is now generally held. Its precise 

 correlation will be discussed beyond. 



THE SUCCESSIVE DEPOSITS IN DETAIL 





In general. — We may now consider each of these deposits in detail, 

 beginning with the lowest, the Bald Eagle conglomerate, and endeavor to 

 trace out the relationship of each series to the earlier and contemporane- 

 ous as well as succeeding formations. From their character and mode 

 of occurrence, we may then attempt to determine their origin and mode 



15 Bull. Geol. Soc. Am., vol. v, pp. 171-176. 



16 Science, loc. cit., 1905. 



17 Section E, Am. Asso. Adv. Sci., Baltimore Meeting, Dec, 1908. Symposium on Cor- 

 relation. Journal of Geology, vol. xvii. See also Science, n. s., vol. xxix, pp. 351-356, 

 Feb., 1909 ; a paper read before the Conference of Eastern Geologists in April, 1908. 



18 Geological reconnaissance in the State of Tennessee, 1st Report, 1856, p. 157. 



