152 NEW YORK STATE MUSEUM 



at least 20 years past. Another quarry is next the highway a 

 quarter mile north of the Cheever mine. A third, the Reed quarry, 

 is in western Moriah just southeast of Broughton ledge and in the 

 curious loop made by the brook which rises at its foot. This last 

 named opening has been more recently worked than the others. 

 The petrography of these rocks has been discussed in the general 

 treatment of the Grenville. 



• 3 Clay 

 The Champlain clays are very generally present upon the flat 

 Paleozoic strata wherever these appear in the larger areas along 

 the lake shore. The clays constitute the surface over the larger 

 partion of the peninsula of Crown point and are widespread in 

 Westport. Should they be needed in the future as the raw ma- 

 terials of brick they could be furnished in any desirable amount. 

 Up to the present the industry is practically undeveloped and these 

 resources may be considered as reserves. It is probable, that like 

 the similar clays elsewhere they would furnish a good grade of 

 ordinary red brick. The sand for' tempering would of necessity be 

 sought in the higher terraces along the Archean front, where the 

 deltas and water-sorted drift contain it. Judicious search would 

 tmdoubtedly serve to locate the sand and clay in proximity with 

 each other. 



Chapter 11 

 MINERALOGY 



The area of the Elizabethtown and Port Henry quadrangles 

 presents some localities of special interest to the student and col- 

 lector of minerals. It is therefore of interest to embody in a special 

 chapter the notes and experience gained while in the field. The 

 minerals may be classed under three or four heads on the basis 

 of association as follows, but it is not intended to include in the 

 list the ordinary rock-making minerals or others which do not 

 exhibit some feature of special interest. The list amplifies in some 

 respects the one given by the writer in the Geology of the Magne- 

 tites near Port Henry, N. Y. [Am. Inst. Min. Eng. Trans. 1897. 

 27:195]. 



1 Minerals of the Paleozoic limestones, embracing occasional 

 calcite crystals and one occurrence of sulfur, derived from the 

 alteration of pyrite. 



2 Minerals of the Grenville limestones, and their associated in- 

 clusions of silicates, viz : calcite, diopside, fluorite, garnet, graphite, 



