2.A. 



NEW YORK STATE MUSEUM 



changed into three different varieties of rock. In one lo or 12 

 feet thick, it is charged with diopside; in the next about 15 feet 

 it has become a black, granular pyroxene which doubtless encour- 

 aged the search for ore; finally the last, about 20 feet thick, is 

 largely changed to garnet and pyroxene, with which apatite is found 

 tinder the microscope. 



East W est 



Anq 



RTHOSITE. 



Garnet , Calcite: 

 Pyroxene: Rock 



Black Limestone. Anorthosite 



P „ CHARGED with 



UlOPSIDE. 



r R O X E M c 



Fig. 2 Cross-section of north prospect, Weston mines, looking south. The 

 strike is N 5 E unless compass was influenced by local attraction. 



One-eighth of a mile to the south one finds another large pit 

 now so caved as to be inaccessible. Erastus Hale of Keene Center, 

 with whom I visited it a second time, called it the " Fifth shaft." 

 The inaccessible rocks had an apparent dip to the west. On the 

 dump was much limestone, charged with pyroxene, lime-silicate 

 hornfels, consisting of green pyroxene containing multiludes of 

 little garnets. There is also a green rock consisting of diopside 

 about 75 per cent and calcite 25 per cent. All these rocks are 

 undoubted contact effects, and the magnetite which was nlined and 

 of which a few stray pieces are still available, was one of the char- 

 acteristic attendant features. 



X X ^'T X X X X X X X X X 



■;■: y X >^ X >ir X X X X X 



X X X X ^ X X . X X X X X 



_:-iX X X X 



X X •>^^^c:;^Zir-rr=rj=.^rt^£r3L_X X X 



X X 



X X 

 X X X "U-5^:;:;^:;:;;^i^j;;ir3r~x' X X 

 X X X X X X X X X X X X 

 X X X X X X X X V X X 



X X X ;'C X X X !)C X X X X 



j Ft, , 



Fig. 3 Sketch of a fragment of Grenville 

 gneiss, caught up in anorthosite. Near Fifth 

 shaft, Weston mines. 



