Faulted Eegion of the Mohawk. 



39 



rapids and falls over the Calciferous which the fault has brought 

 up. In plate 4 the character of the exposure and some of the 

 relations are shown. In the following figure an explanatory 

 diagram is given. 



Figure 4.— Diagram of fault phenomena and dike shown In plate 4. East Canada creek, N. Y. , 

 looking north-northeast. D'. Utica slate. T. Trenton limestone. D. Dike. B. Birdseye limestone. 

 C. Breccia. CA. Calciferous. 



In these illustrations there should be noted the vertical fault 

 plane, the presence of the dike along the fault plane, the typical 

 unbending of the Utioa slates and Trenton beds against the fault, 

 and the breccia which includes a large fragment of Birdseye 

 limestone. 



The Calciferous wall on the west side of the dike is consider- 

 ably fractured and the general southerly dip of the formation, in 

 the fine series of exposures up the creek, gives place to gentle 

 undulations shown in part in plate 4. The breccia comprises 

 angular fragments of Calciferous sandrock (some but slightly 

 out of place) and of Birdseye limestone, in a matrix of sand 

 from the Calciferous beds. The thickness of this breccia varies 

 from three to eight inches. The relations of the large fragment 

 of Birdseye limestone are not clearly exposed, but it appears to 

 be in the breccia and not in regular sequence with the Trenton 

 beds cut off by the dike. 



