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REPORT OF THE DIRECTOR 1923 19 
boulder deposits have been examined along predetermined lines ex- 
tending westward from Rensselaer county, through Saratoga, 
Schenectady and Montgomery counties, and from Altamont south- 
west and west through Albany, Schoharie, Otsego, Chenango and 
Madison counties. Further examination has been made of the St 
Lawrence river lowland near Ogdensburg and Clayton. Specimens 
of these crystalline boulders were collected for thorough petrological 
examination in the hope that some of them may lead to a definite 
correlation with the parent rock. 
A larger part than is generally thought, of the morainic material 
and outwashed gravels of our glacial deposits is of local origin; 
that is, it has not been transported far. By way of illustration, of 
the coarse gravels which are deposited in what is known as the Van 
Rensselaer sand bank north of Albany, which are outwash or esker 
deposits, more than 80 per cent by actual test, show that the ice and 
water movements have carried them for but a relatively short dis- 
tance, not far from the confines of the mass of sandstone and shale 
which makes up a large part of the northern Hudson and eastern 
Mohawk valleys. Crystalline boulders, however, have better re- 
sisted wear and have therefore been able to travel farther, and these 
far-travelled boulders are those which for the most part constitute 
the large glacial rocks scattered over the State. During this season’s 
operations in this field the actual work has been done by Mr James 
ii. C. Martens. 
