310 E. O. ULRICH REVISION OF THE PALEOZOIC SYSTEMS 



most favorably exposed in quarries and cuttings along the Iron Mountain 

 Railroad, which here follows the west bank of the river. Observations 

 were made at frequent intervals between Riverside and Wickes Station 

 below the mouth of Meramec River. 



At Rattlesnake Creek and Bushberg the top of the Kimmswiek is 

 formed by the Receptaculites oweni bed. One-fourth of a mile south, in 

 the Glen Park quarry, the Fernvale rests on a lower bed. Then there is 

 a long bluff to Grand Glaize Creek, showing how the contact descends 

 still farther. Between Sulphur Springs and Kimmswiek there is a minoi 

 syncline, in which the contact rises a few feet. In the last exposure, 

 above the town of Kimmswiek, the contact seems to have descended 

 again. In 5 miles of almost continuous exposure the Fernvale cap main- 

 tains its thickness of a little more or less than 2 feet. 



On the flanks of the Nashville dome the Kimmswiek, with character- 

 istic lithology and fossils, indicating the upper part of the formation, has 

 been observed at only one point, namely, in the southwestern part of the 

 circumference, near Aspen Hill, Tennessee. Here it is over 40 feet thick, 

 and followed in turn by the Hermitage, the Bigby, and the Catheys, all 

 three of Trenton age. The contact with the underlying formation is not 

 seen, but there is no reason to doubt that the Kimmswiek at Aspen Hill 

 rests either on the Carter limestone, which is commonly succeeded by the 

 Hermitage, or on a wedge of Lowville. The latter formation, though 

 usually absent on the west side of the dome, is believed to reach the 

 vicinity of Aspen Hill by overlap from the south. 



Deposits of Cincinnati age (Eden and Maysville) are generally want- 

 ing on the south and east sides of the Nashville dome, but along the west 

 and north a good development of the upper division is indicated by the 

 Leipers formation of Hayes and Ulrich. The Eden is unknown along 

 the Cincinnati axis south of central Kentucky, though the upper member 

 of this group probably extended well on toward the border of middle 

 Tennessee. Crustal movements had caused the withdrawal of the Ordo- 

 vician sea from the greater part of the accessible area previously covered 

 by it. Shrinkage at the same time caused elevation of Appalachia and 

 accentuation, with slight general depression, of the Appalachian Valley 

 troughs, the latter opening the way for the Utica invasion of the North- 

 eastern States to Cincinnati. 



Where the full Utica follows the Trenton the transition is more often 

 gradual than abrupt. However, at Cincinnati, which point was reached 

 by only the last of the Utica deposits, there is clear evidence of erosional 

 unconformity between the Utica and the middle Trenton on which it 

 rests. In middle Tennessee, where the emergence at close of the Trenton 



