GEOLOGY OF THE WHITE MOUNTAIN DISTRICT. 16/ 



holding black tourmaline, small garnets, a greenish mineral not yet deter- 

 mined, apparently a hydrous-mica, occurring in thick lamellre, albite, and 

 others. Some of these veins are three feet thick. A few layers concen- 

 trate a bronze-colored mica ; others consist of what seems at first a hard 

 granite, lacking mica, which is the most characteristic rock throughout 

 the Notch, and is called a granite on p. 123. It so intermingles with 

 what is surely stratified that it cannot be separated from gneiss. So 

 compact are its constituents that they seem as if cemented by an infil- 

 trated silica. Other layers, partly decomposed, show a reddish color 

 from the oxidation of iron and white spots of feldspar. 



The second is a much larger cut than the first, being 450 feet in 

 length and three times as deep as the first. The rocks are the same 

 with those just described, but the veins are larger, more numerous, and 

 somewhat diversified. They contain all the minerals first named, also 

 fluorite, galenite, smoky and transparent quartz crystals, pyrite, pyrrhotite, 

 calcite, siderite or ankerite, and an unknown green mineral. The fluorite 

 is both pink and green. The iron-carbonate has completely oxidized, and 

 the crystals crumble to powder upon exposure, leaving behind abundant 

 bunches of " paint." In other parts of the cut a little copper pyrites and 

 green tourmalines occur. Among the fragments in the pile to the south, 

 I find bunches of chlorite. There is no regularity in the strata or joints 

 in this cut. The vein holding fluorite and quartz crystals runs north and 

 south. The most marked planes that have any resemblance to strata 

 dip S. 78° W. Other veins cross the supposed strata irregularly. So 

 numerous are these veins that Professor Dana, who examined the rocks 

 of this neighborhood with me, suggested they might indicate the pres- 

 ence of an anticlinal axis at this point. Possibly the dip corresponding 

 to this, so as to make the arch, may be the one to N. 57° E. yG" , above 

 Silver cascade, p. 123, though opposing inclinations are not needed to 

 prove the axis in a region full of inverted folds. 



After passing the trestle-work, there is a third excavation known as the 

 "James cut," 250 feet long. This is through the more granitic variety of 

 the hard schist common at the two other cuts. Near its southern termina- 

 tion there is an apparent dip of 70° S. 70° W. A possible dip of 75° N. 

 38° E. is spoken of here. These planes may perhaps be connected with 

 the course of an interesting trap dyke, having the same strike, or N. 52° W., 



