Kemp — (xeologmc of Essex County. 



593 



at 2,203 feet is the culminating point of the largest clump of hills, but 

 farms extend almost to its summit. The drainage of the western part of the 

 town is mainly through Trout brook into the Schroon river in Warren 

 county to the south. The exceptional interest that attaches to the topo- 

 graphic relations of the Schroon lake basin are later commented on. 



Geology. The northern portion of the town is formed by Series III, 

 but almost all the remainder, except for outliers of gabbro, consists of the 

 gneisses and crystalline limestones of Series I and II. A small but 

 extremely significant remnant of Calciferous cherty limestone covers a few 

 acres at Schroon Lake post office. 



Series I. As shown by the map, the southern portion of the town to 

 the extent of more than half its area is formed in largest part of gneisses. 

 The gneisses vary somewhat among themselves, but a light colored, strongly- 

 laminated one, shown by the microscope to consist of quartz, microperthitic 

 orthoclase, prominent garnets and a little hornblende, is a very prominent 

 type. It is the principal rock around Schroon lake, and in the country to 

 the southeast around Mount Pharaoh and Pharaoh lake. Hornblendic 

 varieties also appear that are darker than this one, and still different varieties 

 as noted in the detailed itinerary that follows. 



The valley of Paradox lake is bounded on the south by the limestones 

 of Series II, but on the eastern border of the town, at Nos. 100 and 101, is 

 the Schofield ore-body, whose walls are a massive gneiss, precisely like that 

 which contains the ore at Hammondville. It is little else than plagioclase 

 feldspar and quartz. A few magnetite grains appear, but the rock is a very 

 pure aggregate of the two minerals mentioned, right up to the ore. The hills 

 and ridges in this region are very generally gneiss, while the lower lying slopes 

 and depressions are limestone. Along the highway to Crane pond, No. 97 is 

 a coarse gneiss of mterlaminated flat lenses of quartz and orthoclase, which 

 have evidently been rolled out under dynamic stresses. In the slides, strained 

 or crushed crystals are abundant. Very little hornblende is present. Along 

 the east shore of Schroon lake, the rock is a coarse quartzose gneiss, at times 

 with mica, again w r ith hornblende, and often with garnets, while along the 

 highway which lies in part in Warren county, it is much the same, and is the 

 garnetiferous variety cited at the outset. The same rock makes up the mass 

 of Mt. Pharaoh. A fine illustration of a brecciated gneiss was met at No. 69 

 on Pharaoh lake. This light garnetiferous gneiss leaves a strong impression 

 on the observer that it is clastic in origin, although precise evidence is diffi- 

 cult to obtain. 

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