GEOLOGY OF MOUNT MARCY 



25 



Fifty yards above this pit and on the hillside anorthosite out- 

 crops, in which is caught up a fragment of gneiss as shown in 

 figure 3. It is one of many such cases in the vicinity of the Keene 

 valley. 



One-fourth of a mile or less south of Fifth shaft is a large open 

 cut some 75 feet long and 25 feet deep now caved in with only a 

 few old timbers sticking tfirougih the drift. It is the abandoned 

 Hale mine. The dump, however, shows the usual limestone charged 

 with pyroxene, and the garnet-bearing hornfels. 



The largest workings of all at the old Weston or Wood mine 

 are still farther south and in the valley of the brook which comes 

 down from Cascade mountain. Only the old dumps and the walls 

 of old stalls in which the ore was roasted now remain. Limestone 

 charged with pyroxene, or with garnet, occasionally showing rude 

 crystal outline, or with magnetite, indicate the old mineralogy. By 

 amplifying the available material with the collections made in 1893, 

 a very good idea of the relationships can be obtained. 



N.E. 



Fig. 4 Cross-section near Weston mines, looking southeast 



Figure 4 is plotted from observations made in 1893, in the brook 

 beginning with exposures to the southeast and passing upstream 

 toward the mine. In the section the observer is looking at the south 

 or southeast bank so that the eastern end is at the left. The gneiss 

 first encountered varies somewhat in the slides, but the most import- 

 ant mineral is microperthite in irregular shreds and torn fragments 

 showing the results of crushing and severe pressure. In the first 

 slide it is accompanied by shreds of emerald green augite and pink 

 garnet. A very little quartz may be present, and a very little mag- 



