126 NEW YORK STATE MUSEUM 



evidence. In the more rugged portions of the mountains east of 

 this region where- the faulting was more intense they can sometimes 

 be traced by the crushed condition of the rocks along the line of 

 fracture, or suspicion of the presence of a fault line is aroused by 

 an abrupt and complete change in the kind of the rock. An excellent 

 example of this latter case is the Cascade Lake valley, where the 

 rock on the southeast side is anorthosite, while the opposite side is 

 composed of gneiss. 



One of the striking physiographic features of the Adirondacks is 

 the gridiron pattern of the topography produced by one system of 

 faults, running from the northeast to the southwest, crossing another 

 set at right angles. Many valleys have resulted from this condition 

 and they furnish natural passes for the roads between the separated 

 lowlands. In the central portion of the mountains they are, as a 

 rule, narrow V-shaped defiles, but in the Lake Clear region they are 

 not so marked because erosion has leveled the escarpments and they 

 have been deeply buried in glacial sands. Nevertheless, a number 

 of faults have been positively identified. It would be natural to 

 suspect upon topographic grounds that a fault line exists from 

 Bloomingdale to Saranac lake, as shown on the accompanying map. 

 A steep cliff 2 miles directly south of Bloomingdale is strongly 

 suggestive. The fault line drawn on the map from Saranac lake to 

 Kiwassa lake was proved to be correctly placed by the crushed 

 condition of the anorthosite which has since been welded or rece- 

 mented together at an exposure a mile south of the town of Saranac 

 Lake, and west of Lake Flower. A similar condition exists at the 

 head of Lower Saranac lake not far from where the Ampersand 

 Hotel stood. This fault line is identified farther to the northeast in 

 the town of Saranac by the rusty and crushed character of the dark 

 syenite shown on the side of the state road between the two railroad 

 crossings. Another fault, supported by petrographic evidence, 

 follows the route of the Delaware and Hudson, Chateaugay branch, 

 from Bloomingdale Station southwest. Still another, and to us an 

 important one, runs from Gabriels, Paul Smith's Station, on the 

 New York Central, southwest through Lake Clear itself. The 

 evidence to support this is furnished by the record of soundings in 

 the lake (made by Dr W. M. Smallwood). A submerged channel, 

 varying from 30 to 40 feet deep, runs northeast-southwest. A cross 

 fault, belonging to the other system, is likewise shown by the sound- 

 ings. This runs from the swamp south of Upper St Regis lake south- 

 east through the bay of Lake Clear, sometimes referred to, locally, 



