40 Report of the State Geologist. 



The dike was recently described by C.H. Smyth,* who incidentally 

 refers to some of its relations. Its thickness in this exposure is 

 from eight to ten inches, and it is accompanied by a thin adjoin- 

 ing vein of calcite, carrying pyrite and galena. An adit was run 

 in on the vein some years ago in the hope that it might be found 

 metalliferous, and, according to Smyth, it was found that the 

 dike ends at about sixty feet. Its extension along the surface 

 southward was not found owing to drift and debris. The rock 

 is described by Smyth, and in a supplemental paperf is stated to 

 be alnoite, containing the rare mineral melilite in considerable 

 amount. 



The amount of displacement of the fault is about sixty feet, 

 not counting the upturn of the beds on the downthrown side. 

 This upturn extends for about 100 yards from the fault and 

 gradually gives place to gentle southwest dips. The Trenton 

 limestone exposed is nine feet in thickness, in layers three to eight 

 inches thick. It is abruptly terminated by Utica slate beds with 

 a six-inch layer at their base. In its extension northward, the 

 fault diverges from the creek at a small angle and appears to be 

 lost in Utica slates in the hills west of Crumb creek, but owing 

 to heavy drift cover, it could not be followed any great distance. 



Ascending the creek above the fault, there is the fine series of 

 exposures of Calciferous shown in plate 8, with others extending 

 to Ingham's Mills, all dipping gently southwestward. Above 

 the mills the Birdseye, Trenton and Utica formations extend 

 across the creek in succession. Half way between Ingham's 

 Mills and Dolgeville, the dips suddenly change to northeast, and 

 increasing rapidly in amount, bring up the Trenton, Birdseye 

 and Calciferous beds in succession on the east bank of the creek ; 

 a fault also developing which increases rapidly northward. This 

 fault is shown on plate 2. 



In the following figure the four sections illustrate the develop- 

 ment and relations of this uplift. It will be noted that this fault 

 differs from the two others described, in having the uplift on the 

 eastern side. The upturned Utica slates are finely exposed along 

 the high eastern bank of the creek to the high falls below Dolge- 

 ville. North of the falls there is a low cliff of Calciferous which 



* Am. Journ. Sci., 3(1 Series, vol. 43, pp. 322-327. 

 + Am. Journ. Sci., 3d Series, vol. 46, p. 104. 



