80 NEW YORK STATE MUSEUM 



the only development consisting of temporary and small-scale 

 operations to supply local needs in the way of road metal or founda- 

 tion stone. 



In its topography the region is a plateau which slopes to the west 

 and northwest, the surface broken by ridges and hills of incon- 

 siderable altitude. The elevation of the interior ranges from about 

 1500 to 2000 feet, while the outer border where the crystalline 

 formations disappear beneath the Paleozoic sediments lies for the 

 most part between the approximate limits of 400 and 700 feet, but 

 is somewhat higher than that on the south. The interior is largely 

 wilderness and accessible only in restricted districts where one or 

 two branch railroads have been extended eastward from the main 

 lines which skirt the borders. Of these, the Carthage & Adiron- 

 dack Railroad belonging to the New York Central system is the 

 more important and runs from Carthage at the contact of the 

 Paleozoic strata with the Precambric complex in a direction north 

 of east across the central part of the highland as far as Newton 

 Falls near the outlet of Cranberry lake. The few small settlements 

 that exist in the interior are mainly dependent upon lumbering and 

 the summer visitor for support. There is little local demand for 

 building material of permanent nature. 



Of the crystalline formations the gneisses and schists are most 

 prominent, but massive rocks occur in several rather extensive 

 areas. Granite, syenite and gabbro are the principal representa- 

 tives of the igneous rocks. They constitute dikes, stocks, and 

 larger irregular bodies that may be called bathyliths, all Precambric 

 in age though widely separated no doubt in the intervals of in- 

 trusion. The term " massive " is hardly applicable to their general 

 field appearance since they often pass by insensible gradations 

 from such condition into gneissoid and schistose phases, scarcely 

 distinguishable from some of the country formations which are 

 made up of an unresolved complex of gneisses and schists with the 

 more characteristic members of the sedimentary or Grenville series, 

 the latter including quartzose, mica and hornblende schists, amphi- 

 bolites, graphite schists, quartzites and crystalline limestones. 



The massive granites of this region have for the most part de- 

 cided colors, ranging from pink to dark red in the different occur- 

 rences, while the very light and gray shades are relatively uncom- 

 mon. They are generally rather coarse in grain, but finer sorts occur 

 as local modifications of the coarse rocks or in separate intrusions. 

 The predominant reddish color is imparted by the feldspar of which 

 the prevailing variety is microcline. Hornblende and biotite (both 



