76 NEW YORK STATE MUSEUM 



deltas as the water level fell. It will be an interesting matter to 

 determine if any correlation be possible between these levels and 

 corresponding ones formed by West Canada creek. 



South of Dolgeville, and east of the creek, is a sand terrace with 

 summit level of 800 feet, and a line of morainic hills to the east 

 which culminates in the knob just opposite Dolgeville. The sand 

 overlies till, has a depth of from 20 to 40 feet, and seems to be a 

 delta deposit, of East Canada creek in all probability. 



The sand and gravel shoulder about Herkimer, with summit at 

 about 600 feet, has been correlated by Brigham with similar de- 

 posits farther up the Mohawk valley at the same approximate 

 level, all of which he regards as having been formed in a small 

 lake with water at the 600 foot level, held up partly by ice at Little 

 Falls and partly by the rock barrier there, since trenched by the 

 river. 



Below Little Falls is a prominent sand and gravel terrace, with 

 much coarse gravel on the north side of the river, whose summit is 

 between 460 and 480 feet. It is found on both sides of the river, 

 though most extensively and least interrupted on the north. 

 Though slightly higher, these levels are quite concordant with 

 those of the similar deposits described by Brigham as extending 

 from East Creek (just beyond the map limits on the east) down to 

 Amsterdam, at about the 440 foot level, and regarded by him as 

 indicating static water at that level, held up by some as yet un- 

 known barrier at or below Amsterdam. 



At several localities finely laminated, plainly water-laid clays, 

 nearly or quite destitute of pebbles, were noted. They seem of 

 necessity to mark static water conditions, yet are at such vary- 

 ing altitudes, and run up to such high levels, that they can be attri- 

 buted only to a series of wholly independent and very local water 

 bodies. 



Just west of Dolgeville is a flat topped, steep fronted sand and 

 gravel terrace with a summit elevation of 840 feet. One and one 

 half miles north of Dolgeville, on the divide between Spruce and 

 Cold creeks, are finely laminated clays at 900 feet. The lamina- 

 tion is so fine and even that the material was mistaken for 



