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Report of the State Geologist. 



interrupted by a wide marshy and by protruding ledges of rock, but after an 

 interval of a mile it again appears and runs north to the Chazy-Champlain 

 line, finally disappearing one-half mile beyond that line. It rises, in general, 

 about thirty feet above the ordinary level and the base has a width of a 

 quarter of a mile. Its surface is 120 feet above the level of lake Champlain. 

 It does not exhibit its entire mass, as its base is buried in Champlain clay. 

 Assuming that the disconnected portions are parts of a single ridge, as seems 

 highly probable, its entire length is ten miles. No good sections are exposed. 

 A three-foot cut in it, two and one-third miles southwest of Chazy village, 

 frequently shows somewhat rounded boulders mostly of Potsdam sandstone, a 

 few of which reached one foot in diameter, embedded in a matrix of coarse, 

 brown sand. No signs of stratification were visible, but the opening was not 

 a very recent one. 



Champlain deposits. The term " Champlain," as here used, merely serves 

 to discriminate the deposits formed under water in the Champlain basin, from 

 those formed upon -the land. During and after the retreat of the ice, the 

 glacial deposits on the low strip were covered by deposits laid down in the 

 marginal portions of the body of water that occupied the basin at that time, 

 the present lake being its shrunken remnant. The mountain streams' brought 

 down vast quantities of sand, building up large deltas at their mouths, and of 

 mud, which was deposited farther out and also along shore between the 

 deltas. As the water level fell from time to time, the sand deposits were 

 pushed farther out and formed at lower levels, covering up the clays of 

 the preceding stages. During much of this time the Champlain basin was 

 occupied by an arm of the sea, and the marine clays and sands are fossiliferous. 

 The fossils can be collected in abundance at several points in the county. The 

 sand delta deposits formed by the Saranac, Ausable, Little Ausable and 

 Salmon rivers are very widespread in the eastern part of the county. At the 

 higher levels thej are confined to their respective valleys, but lower down 

 they become confluent. Much of the eastern portions of Ausable, Peru, 

 Schuyler Falls and Plattsburgh townships is covered by a wide, dreary 

 expanse of sand, often bare, sometimes with a sparse covering of coarse grass 

 with huckleberries and stunted pines, and which is dreary and monotonous in 

 the extreme. Dunes are quite frequent, especially where the sand has been 

 trenched by the present streams. 



Some of tiie evidence collected indicates that at first the water level 

 was at a greater altitude than has heretofore been recognized. Both in 

 the Saranac and Ausable valleys, the sands have been found to run up to 



