OLENTANGY SHALE AND DEVONIAN DEPOSITS 485 



the similar one in western New York, 1 although many other forms 

 are also common to the Encrinal limestone of the two regions. 



The fossils in the beds immediately below the Prout limestone 

 are more abundant than in the shale just below the Encrinal lime- 

 stone of Ontario. In this respect the northern Ohio deposit shows 

 more decided relationship to the western New York section. In 

 fact, the upper part of it includes a portion of the fauna of the 

 "Demissa bed," although it lacks Spirifer granulosus and some of 

 the other prominent forms. However, this suggested relationship 

 with the New York section is not fully substantiated. 



In addition to the marked lithological similarity and strati- 

 graphic relation of the Prout and Encrinal limestones, over 75 per 

 cent of the fauna of the Prout limestone also appears in the Encrinal 

 limestone of Ontario, and the upper layers contain many of the corals 

 of the coral zone at Arkona, Ontario. It seems reasonably certain, 

 therefore, that the Prout limestone is the Ohio representative of 

 the Encrinal limestone to the north and perhaps to the east as well. 



At Kettle Point, Ontario, the Devonian black shale rests upon 

 a limestone of the Hamilton which lies about 150 feet above the 

 Encrinal limestone, and well-records 2 show that this is the usual 

 succession of beds in Lambton County, Ontario. In Middlesex 

 and Kent counties, which lie to the south of Lambton, this limestone 

 is sometimes present, but at other places is wanting, 3 as might be 

 the case where erosion has taken place prior to the deposition of 

 the black shale. The Huron, or basal portion of the Ohio, lies 

 directly upon the Prout limestone at Sandusky. It therefore either 

 represents the upper Hamilton shale and limestone of Ontario, or 

 these deposits are wanting in northern Ohio and the Huron shale 

 rests unconformably on the Encrinal limestone. On the basis of 

 the fossils and the occurrence of spheroidal concretions in both 

 deposits, Kindle has correlated the black shale at Kettle Point, 

 Ontario, with the Huron shale of northern Ohio. 4 If this correlation 



1 Bulletin of the Geological Society of America, Vol. XIII (1902), 164, 166. 



2 H. P. H. Brumell, Geological Survey of Canada, Ann. Repl., V, Part Q (1892), 

 61-70. 



3 Ibid., pp. 52, 73, 74. 



4 Geological Survey of Canada, Summary Report for igi2 (1914), pp. 287, 288. 



