50 NEW YORK STATE MUSEUM 



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rocks, west and northwest of Cannon Corners, and traversed 

 the road from White School to the Rebideau farms. Fourth, Arm 

 strong's Bush, an indefinite rocky area on the north edge of the 

 map, which records the latest glacial stream flow in the State. 



The heavy delta tracts of coarse materials are the product of the 

 copious drainage noted, above, of which two are of special note. 

 The southern arid earher delta tract is the belt of bouldery, cobbly 

 stuff, complicated with moraine piling, lying west of West Beek- 

 mantown and West Chazy, the effects of the Altona drainage. The 

 later large and coarse deposit is on the west edge of the Mooers 

 sheet at the north, and related to the bare rock areas on the west. 



West Chazy district. In this district, the southern part of the 

 Mooers sheet, is a remarkable display of summit shore features. 

 The copious drainage from the Altona rocks supplied superabund- 

 ance of very coarse material for work of the waves, while the ice 

 built its frontal moraines as a foundation for bar construction. 

 We have here a complex of features which will be misinterpreted 

 and wrongly diagnosed by the geologist who has not had experience 

 with such deposits. Here is the work of powerful torrential waters 

 mingled with morainal material, and then more or less modified 

 or reshaped by the wave-work of the highest static waters. The 

 effects of the three agencies are mingled in varying proportions and 

 it is often difficult or even impossible to discriminate the wave 

 work, especially at the topmost line of the standing waters. In 

 some cases the approximate summit is marked by wave embank- 

 ments, but commonly the unmistakable bars are inferior to the 

 summit level. 



On the junction of the Mooers and Dannemora sheets the sum- 

 mit beach lies against a steep slope at slightly over 700 feet. Imme- 

 diately west of the four corners, at the bottom edge of the Mooers 

 sheet, is a heavy bar ridge with precise altitude (U. S. G. S.) 684 

 feet; and just east of the corners is another strong, conspicuous 

 cobble ridge at 660 feet. The south termination of the delta tract 

 is seen on the Dannemora sheet, plate 8. Northward on the north- 

 leading road the delta gravels are shaped into indefinite ridges at 

 about 700 feet. The photograph is plate 16. 



One-half of a mile west by south from West Beekmantown is an 

 isolated ridge, probably morainal, rising to 700 feet. About the 

 south end of the ridge are heavy bars of boulder and cobble. On 

 the east slope at the north end the ground is so rough that no one 

 would suspect it to have been subjected to centuries of heavy wave 

 action. It is a good example, that can be indefinitely multiplied, of 

 the nonvalue of negative shore-line characters. 



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