251 
In the bed of the Cincinnati creek the joints are enlarged and forms 
an underground course. The stream disappears for several hundred yards. 
The contorted layers in the Trenton Falls section are in two distinet 
horizons. The lower one is from 4 to 6 feet thick and les at the crest of the 
lower part of High Fall. It outcrops also in the upper end of the gorge near 
Prospect. According to the measurements of Prosser and Cummings it lies 144 
feet below the top of the Trenton. 
The second layer is from 8 to 15 feet thick and shown along the path oppo- 
site High Fall and may be traced to Prospect. It lies 65 to 70 feet below the 
top of the Trenton. : 
Such contortion of strata does not appear in the outcrop of Trenton 
exposed along Mill Creek. 
Vanuxem suggested that as the folded layer was more ecyrstalline than 
the layers above or below, the expansion of crystallization was manifested in 
the contortion of the erystalizing layer. 
T. G. White discovered overturned fold, cross-bedded, channel filling 
structures that must be explained by other means which would yield a con 
siderable expansion in excess of the crystallization. 
W.J. Miller states that it is thought that the folded structure at Trenton 
Falls was in reality caused by a differential movement within the mass of the 
Trenton limestone. That the whole body of the limestone has been moved 
is clearly demonstrated by the existence of the thrust fault at Prospect. It is 
easy to see how when the force of compression was brought to bear in the 
region there would be a tendency for the upper Trenton beds on the upthrow 
side to move more easily and consequently faster than the lower Trenton 
beds. A similar explanation would apply to the lower folded zone. The folded 
zones thus indicate horizons of weakness along which the differential move- 
ment has taken place. As thus explained it is evident why the strike of the 
minor folds, the strike of the fault, and the strike of the large low folds of the 
region should be parallel, and why the contorted strata should be so local in 
occurrence, because all the phenomena were produced by the same local 
pressure. The differential movement would also readily account for the 
rubbed or worn character of the upper and lower sides of the contorted zone. 
The topography of the limestone region, underlain by the Trenton, Black 
river, Tribes Hill and Little Falls dolomite is given by E. R. Cummings, who 
states in describing the Mohawk valley near Amsterdam, that the lime- 
stone region is characterized by a low, rolling relief and shallow stream val- 
