294 H. p. GUSHING FAULTS OF CHAZY TOWNSHIP, NEW YORK. 



block between H-H and I-I is a wedge thrown down between the adja- 

 cent blocks to the north and south, these last being in substantial accord. 

 Their continuity has not been affected by the faults, which have simply 

 thrown down the intervening block. 



Fault K-K. — At the extreme southeastern limit of the area shown on 

 their map, Brainard and Seeley met and noted evidence of this disloca- 

 tion. The testimony, as to its reality and position is of the same un- 

 equivocal character as that for the other faults, and, as the Black River 

 limestone furnishes in every case the most convenient horizon for use in 

 defining the fault, the corroborative evidence of other horizons may be 

 omitted from the discussion. The Black River, south of the fault, lies 

 85 yards to the east of the same bed north, measured normal to the 

 strike. This, together with the low dip, indicates only a slight throw for 

 the fault — 40 feet as a maximum, with the throw to the south. 



SUMMARY OF THE FAULTS. 



From the preceding descriptions it may be seen that the assemblage of 

 faults E to K, inclusive, are peculiar in certain respects. The zone lying 

 between the great faults A and C is greatly shattered, not only absolutelj^ 

 but also when compared with the rest of the area under discussion. The 

 zone between faults B and C will answer best for comparsion. Though 

 the work on that zone is somewhat incomplete, it is evident that it has 

 suffered far less from faulting than the other. As has already been indi- 

 cated, the disturbance around Chazy village is greater than can be dis- 

 played on a map of small scale. Witness the outcrops of Black River 

 limestone along fault A- A between the Potsdam and the Chazy.* 



Two possible explanations of the disturbed zone at Chazy village sug- 

 gest themselves to the writer. One has already been hinted at, namely, 

 that faults A-A and C-C form a sort of double fault, or, in other words, 

 may be considered as one fault with a crushed zone of unusual width.f 



The second explanation would perhaps be a more natural one. If the 

 three faults A-A, B-B and C-C are prolonged northward, holding approx- 

 imately the same trends, they may perhaps come together — that is, the 

 three faults may have been formed by the subdivision of one fault. What 

 seems a similar case is exhibited north of Plattsburgh, where the fault 

 B-B separates into two branches, bringing up a wedge of Chazy between 

 the Calciferous and Trenton. J This wedge is much shattered and broken 

 in a manner quite similar to that in the region around Chazy. Brainard 

 and Seeley 's map of Providence island and the neighboring portion of 

 South Hero seems to illustrate a similar case.§ 



* See ante, p. 293. -f See ante, p. 290. J See ante, p. 290. 



g Bull. Am. Mus. Nat. Hist., vol. iii, no, 1, pp. 18, 21. 



