NORTHERN SECTIONS APPALACHIAN REGION 400 



tion of eastern New York/ 5 which appeared in the Report of the State 

 Paleontologist for 1903, published February, 1905. 11 Here he gave fur- 

 ther stratigraphic reasons for assigning the age of the Shawangunk to 

 the Salina, but regarded the Oneida as the equivalent of the Oswego 

 sandstone. Finally, in May, 1907, he reviewed the stratigraphic position 

 of the Oneida conglomerate, with the conclusion that it should be re- 

 garded as the equivalent of the Upper Medina. He also quotes a letter 

 of Col. E. Jewett, published in the American Journal of Science for 

 1864 (volume xxxviii, page 121), in which he announced the finding of 

 Arthrophycus harlani in typical Oneida conglomerate, and gives it as his 

 opinion that the age of that rock is Medina. 12 The discovery of the 

 Eurypterus fauna at Otisville gave paleontological corroboration to the 

 stratigraphic interpretation, since this fauna is essentially the same as 

 that found in the basal Pittsford shale of the Salina in western New 

 York, 13 discovered shortly before by Sarle. 



It thus became evident that the Shawangunk conglomerate must be 

 separated from the other conglomerates and placed at a higher level in 

 the stratigraphic column. This conglomerate crops out along the Hel- 

 derberg-Kittatinny-Blue Mountain Ridge, from near Binnewater, New 

 York, to some distance beyond the Lehigh Water Gap in Pennsylvania, 

 but with extensions southward into Maryland. The continuous mapping 

 along the Blue Ridge of a single formation on the geological map of 

 Pennsylvania is, therefore, erroneous, for the "Oneida" sandstone, which 

 forms the Front Ridge northeast of the Susquehanna Gap, is the much 

 younger Shawangunk, while the "Oneida" of that gap is the Tuscarora. 

 In the ridges to the westward the Tuscarora and the underlying Juniata, 

 mapped as Medina, represent, respectively, the Oneida, with perhaps 

 some Medina, and the underlying Queenston shales of Upper Ordovicic 

 age, as first pointed out by me in 1905. Finally, the "Oneida" of the 

 westernmost monoclines or Bald Eagle Mountain and of some of 11, 

 ridges to the east, is a still older conglomerate, the Bald Eagle, now r< 

 garded as of Lorraine age. To this conglomerate I at first gave the na 

 Tyrone conglomerate 14 from Tyrone Gap, a name which was, howe\.. 

 preoccupied, and so T was forced to change if to Bald Eagle conglomerate. 

 The equivalency of the Oswego sandstone with (lie upper pari of (his 

 sandstone I pointed out at the Baltimore meeting of Section E of the 



11 Bull. 80, New York State Museum, pp. 342-358. 

 "Bull. 107. New York State Museum, pp. 29-38 



Now v! 1 rV \ ( ?? rk0 : Th0 Eul TPterus shale of the Shawangunk Mountains m eastern 

 New \ork. Ibid., ,,,,. 295-310, plates i-viii. 

 "Science, n. s., vol. xxlx, p. 355, 1900. 



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