290 H. p. GUSHING — FAULTS OF CHAZY TOWNSHIP, NPJW YORK. 



It has been traced for a distance of two miles and a half, but as it then 

 passes at both ends into country heavily drift-covered, further tracing 

 is impossible. Between it and A-A lies the zolie of much faulting. To 

 the east of it is a tolerably regular and nearly continuous section rang- 

 ing from the upper Calciferous to the Black River limestone, with a dip 

 and strike which correspond with those in the Potsdam west of A-A, 

 while the varied dips and strikes in the shattered zone between the two 

 faults bear no apparent relation to either. If, however, these two faults 

 are considered as genetically connected — that is, as forming practically 

 one fault, with the zone between regarded as merely an unusually wide, 

 crushed strip — the apparent lack of relationship is at once explained. 

 Both faults are dip-faults and the combined throw is about that esti- 

 mated for the fault A-A, or 2,000 feet. The Little Chazy river follows the 

 fault-line C-C for two miles, then, near Chazy village, passes from it to 

 fault H-H, which it follows to A-A, where Tracy brook joins it. 



Fault B- B. — This is a third great north-and-south dislocation, which 

 is first discernible at a point about a mile and a half east of Chazy village, 

 north of which point outcrops are too few and meager to permit of fol- 

 lowing it further in that direction. Its trend, however, suggests a possible 

 junction with the fault A-A somewhere to the north. Where first recog- 

 nizable the higher beds of the middle division of the Chazy are exposed 

 on the west side of the fault-line, and outcrops of an horizon somewhere 

 in the Trenton on the east side, these last lying at a level 100 feet lower 

 than that of the beds across the fault-line. Outcrops on the east side of 

 the line are few and far between, but the fault can be traced with tolerable 

 certainty to the shore at Monty's bay, where it passes beneath the lake. 

 It reappears on the opposite side of the bay and is traceable all the way 

 across Beekmantown township, next south, into Plattsburgh township, 

 a distance of between ten and eleven miles. Throughout Beekmantown 

 township the entire Chazy is faulted out along this line. In north Beek- 

 mantown an horizon low down in the Trenton is exposed on the east side 

 of the fault, and an unknown horizon in the Calciferous on the west side. 

 Assuming that the thickness of the Chazy here is the same as in Chazy 

 and Plattsburgh townships — that is, in the neighborhood of 750 feet — the 

 throw of the fault here is an as yet unknown amount in excess of that. 

 At the Plattsburgh-Beekmantown line the fault seems to divide, enclos- 

 ing a much faulted block of Chazy and Black River limestone between 

 the Calciferous and Trenton. Still farther south, at Blufi" point in Platts- 

 burgh, the Trenton is faulted down against the Chazy on the prolonga- 

 tion of this fault-line. If this prove to be the same fault its known 

 length is increased an additional five miles. 



Summary of Faults of the first Class. — The three faults just described 



