REPORT OF THE DIRECTOR I915 S^ 



scattered over the area, although they appear to be more numerous 

 on the southwest and northeast, at the extremities. The ore is 

 sphalerite, usually of dark, nontransparent character mdicative ot 

 a relatively large iron content, associated v^^ith pyrite and occasion- 

 ally with a little galena. The wall rock invariably is limestone of 

 the granular metamorphosed type that is an important element of 

 the Grenville strata in the Adirondack region, and is folded and 

 contorted, usually resting at a high angle. Quartzites and various 

 feldspathic schists and gneisses accompany the limestone as a part 

 of the same series. The. mineralization is in the form of lenticular 

 bodies, streaks, bands, and zones of disseminated ores within 

 impure beds of the limestone. At times they show a high degree 

 of crushing and brecciation, the fragments having been recemented 

 by fiowage of the limestone or infiltration of mineral matter in 

 solution. Apparently the formation of the ore bodies dates back 

 to an early geologic period, probably the Precambrian. The area 

 comes within the Gouverneur quadrangle of which the geological 

 survey is now in progress. 



Molding sands. A preliminary paper on the Albany molding 

 sands was prepared as a contribution to a discussion of the subject 

 at a meeting of the American Foundrymen's Association. It is 

 planned to complete the study with laboratory investigations of the 

 physical and chemical properties of the sands, as soon as the neces- 

 sary opportunity is presented. The molding sands have an inter- 

 esting geological history, being one of the deposits formed in the 

 expanded waters that occupied the Hudson valley in late Pleistocene 

 time and that have become known as Lake' Albany. The sands 

 were the last of the sediments then laid down and originally formed 

 a mantle over the whole area covered by the waters, which reached 

 up to nearly 406 feet above present sea level. Since their deposi- 

 tion they have been partially removed by erosion of the streams 

 arid have been shifted about by the winds, the latter agency having 

 a prominent part, it would appear, in the formation of the molding 

 sands proper. The field work has brought to' light a number of 

 features of scientific and practical import. The account of these 

 molding sands referred to is printed in the appendix to this report. 

 Hudson River clays. An investigation of the clay beds in the 

 Hudson valley with particular reference to the possible extension 

 of their uses, hitherto confined practically to the manufacture of 

 common grades of building brick, seems to be a present need that 

 is emphasized by the unfavorable conditions obtaining in the brick- 



