REPORT OF THE DIRECTOR I913 71 



material enlargement of the productive industry which has long 

 been an important one. Recently the resources of the Highlands 

 region have shown the greatest interest perhaps, although develop- 

 ments have continued in the Adirondacks where the principal mines 

 are now situated. Additional details in regard to the economic 

 situation of the mineral resources will be found in the report al- 

 ready mentioned. 



Report on quarry materials. Owing to the press of other work, 

 it has not been possible to extend the investigation of the quarry 

 materials beyond the crystalline rocks, and consequently the prepa- 

 ration of a comprehensive report on the subject which was men- 

 tioned last year as in progress has had to be postponed for the 

 present. The matter already in hand has been made ready for pub- 

 lication and will be submitted for that purpose unless the field 

 work can be resumed during the coming season. The part com- 

 pleted covers the crystalline silicate rocks and the marbles, the 

 materials that have received the least attention in previous work in 

 the field. 



Molding sand. Some of the molding sand localities in the vicin- 

 ity of Albany were visited last summer for the purpose of procuring 

 samples for the Museum collections, and the opportunity was used 

 to study the features surrounding the occurrence of this material. 

 The origin of the sands and of their peculiar qualities which give 

 them industrial value have received little attention hitherto beyond 

 brief statements included in some of the areal reports on the Hudson 

 river region and one or two other publications. 



Stoller in his report on the " Glacial Geology of the Schenectady 

 Quadrangle " remarks that the deposits in that vicinity do not occur 

 at any definite level, but rise and fall with the surface contours, 

 a feature which is true for the sands throughout the region. Al- 

 though they are restricted to the flat-terraced area of sands, gravels 

 and clays accumulated in the glacial Lake Albany, there is a varia- 

 tion of 200 feet in the elevations at which they are found in the 

 section around Albany and Schenectady. Moreover, the sand in any 

 particular locality follows the minor surface irregularities with a 

 variation sometimes of as much as 20 feet between the high and 

 low places. Any sudden and pronounced change in the topography, 

 however, such as caused by a stream cutting into the terrace, marks 

 the disappearance of the valuable sand. The thickness of the sand 

 ranges from a mere film to several feet. Eight or 9 feet was stated 

 by the gatherers as the maximum known to have been excavated 

 in the vicinity, but the average is probably not over 30 inches. 



