CINCINNATIC PERIOD 531 



| McMicken zone 60 feet. | In t Lorraine f New York. 



Edenian i Southgate zone, 120 1 feet. Y Fnmkfllrt and Pulaski of New York. 



( Economy zone, 80 feet. . J 



Ordovicic. 



Fulton ( = Utica), 5 feet. 



The Ordovicic period was closed by the Utica emergence. As has been 

 seen, this emergence was widespread, and even the greater part of the 

 early Utica sea was finally eliminated. This condition apparently con- 

 tinned into the Lorraine. If the necessary maps conld be made, however, 

 it is thonght that the paleogeography would show either a stationary or 

 a slightly enlarged sea during the Frankfurt and Lorraine, this having 

 been brought about by the Taconic revolution of long duration in the 

 Appalachian region. It began in the Trenton and persisted nearly to 

 the close of the Cincinnatic, during which time the older Paleozoic strata 

 were folded all the way from southern Virginia to Newfoundland. In 

 this eastern region, therefore, the life of the later Utica, Frankfurt, and 

 Lorraine was greatly affected not only by the large influx of mud and 

 sands, but even more by the shallowing of the Appalachian waters. In 

 the northeast, in the Saint Lawrence sea, these effects were perhaps more 

 pronounced than in the Appalachian trough south of New York. 



West of the Cincinnati axis, all of America was elevated above the sea 

 during the Utica, Lorraine, and earliest Eichmondian, but in later Eich- 

 mondian time there was again widespread submergence. Nearly all of the 

 Utica is absent at Cincinnati and to the south, but to the north the deep- 

 well borings show more and more of this formation. With the Edenian, 

 which also includes the Frankfurt of New York, the sea again returned to 

 the Cincinnati area, and this invasion is thought to have marked the be- 

 ginning of the Cincinnatic period. To the east of the Cincinnati axis the 

 Appalachian sea was fairly constant in areal extent to the close of the 

 Lorraine, when more and more of the marine waters here subsided. In 

 the Cincinnati region, the Maysvillian sea was apparently continued with- 

 out break into that of the early Eichmondian. This sea then spread west 

 of the axis and united with the widespread flood of the later Eichmond, 

 which came in from the Arctic and Pacific areas. In extent this trans- 

 gression stands second in comparison with that of the Trenton sub- 

 mergence. 



On faunal grounds there is decided evidence for placing the Edenian 

 and Maysvillian, together with the Eichmondian, in the Cincinnatic sys- 

 tem. These three series are united by about 5 per cent of the fauna that 

 is common to all of them, while of the Edenian species about 14 per cent 

 pass into the Maysvillian, and of the latter about 12 per cent occur in the 



