292 H, p. CUSHING — FAULTS OF CHAZY TOWNSHIP, NEW YORK. 



crops are tolerably plentiful, disclosing no rocks of other age than lower 

 Chazy. Accurate determinations of dip and strike are attended with 

 much difficulty, but the data at hand suggest that faults are present. 

 In the state of our knowledge the relations north and south of the marsh 

 are best explained by the presence of a break of some sort somewhere 

 beneath the marsh, with a downthrow to the north. 



Supposed Fault N-N. — If the beds of lower Chazy age exposed just east 

 of the southern end of fault A- A were prolonged south westward in the 

 direction of their strike they would pass to the west of the Calciferous 

 exposures at West Chazy, which have an easterly dip. These Chazy 

 beds, however, are tolerably near the fault-line of A-A, so that their in- 

 clination and strike may be merely local. A fault along the line N-N 

 would make the relations between the two clear, but the evidence of its 

 presence is slight. 



Summary of Faults of the second Class. — Faults like L-L and M-M seem 

 to be distinguishable from those of the first class in their inferior magni- 

 tude and extent. The evidence at hand indicates that they are subor- 

 dinate to the main faults, and represent breaks in the blocks lying be- 

 tween them. If this conception be the true one, these faults of the second 

 class should be limited each to a single main fault-block, should be cut 

 off at the great faults and not pass across them. Proof that they are 

 really so cut off is difficult to obtain, though the negative evidence all 

 points in that direction. 



FAULTS OF THE THIRD CLASS. 



Faidt E-E. — The thrown block of the great fault A-A has suffered much 

 minor dislocation, being separated into a series of small blocks by a 

 number of faults, which are roughly normal to A-A. Near the fault- 

 line, however, the confusion is so great as to preclude detailed mapping. 



As the township is entered from the north along A-A, fault E-E, the 

 first of the series, is met. North and south of the fault are ridges of 

 middle and upper Chazy beds followed by the Black River limestone. 

 The fault is a dip-fault with a heave of about 400 yards, the beds on the 

 south side of the fault lying about that amount further east than the 

 corresponding beds to the north. The amount of heave, taken in con- 

 nection with the angle of dip, indicates a vertical throw for the fault of 

 from 200 to 250 feet, with the downthrow on the north. 



Fault F-F. — The ridges of rock south of fault E-E extend but a short 

 distance southward, and are then abruptly cut off along the strike at the 

 line F-F. Just south of this line outcrops are absent, except for a con- 

 siderable knoll of Black River limestone which lies close to the railroad 

 and very near fault-line A-A. It lies a full mile to the west of the Black 



