44 Keport of the State GEOLoaiST. 



Through this ridge the river has cut a narrow gorge with high 

 walls of Calciferous, which are seen to be underlain for a short 

 distance by crystalline rocks. The river winds slightly in the 

 eastern portion of this gorge, and the short, sharp spurs of the 

 high cliffs have given rise to the appellation of the " Noses," 

 which is well known to travelers along the Mohawk as a particu- 

 larly wild and picturesque part of the valley. This dislocation 

 is shown in plate 2. The fault is not so great in amount as that 

 of Little Falls, and the crystalline rocks are not so extensively 

 exposed, but owing to oscillations in dip, the walls of Calciferous 

 extend much farther up the river. The Trenton and Utica 

 formations extend continuously along the south side of the 

 gorge, beginning in an upper terrace lying a short distance back 

 from the crest of the Calciferous cliff. On the nort side of the 

 river these formations extend to nearly opposite Spraker's Basin, 

 below which the Calciferous extends widely to the north, and 

 eastward to the fault, where it ends in a prominent scarp. This 

 scarp is elevated high above the rolling surface of the Utica slate 

 region eastward. The crystalline rocks at the " Noses" on the 

 Mohawk do not extend quite to the fault, but, as shown in sec- 

 tion A, plate 2, rise in a low anticline just west, to an extent of 

 about forty feet above the river on the south side, and seventy - 

 five feet on the north side. Possibly in the river trough, where 

 the Calciferous is deeply eroded, the crystalline rocks may extend 

 to the fault. 



South from the river the relations of the fault are well exposed 

 on the road to Curry town, which crosses it three times. The 

 Calciferous rises as a wall or steep slope, with the Utica 

 slates abutting against it and dipping away at angles, for the most 

 part averaging 50°. This dip rapidly decreases eastward and 

 finally gives place to the gentler general southwesterly inclina- 

 tion. The essentially vertical position of the fault plane is clearly 

 exhibited between Currytown and the river, not only in many 

 small exposures of a perpendicular fault scarp but in its straight 

 course up the long slope, aggregating over 200 feet in ascent.. 

 Half a mile north of Currytown the Trenton and Birdseye lime- 

 stones are seen overlying the Calciferous and, in a short distance 

 up the slope, the Trenton limestone passes beneath the Utica 

 slates. The Calciferous along the fault is often considerably 



