34 NEW YORK STATE MUSEUM 



accompanying map. One of them is in the quartzite ; the others are 

 in amphibolitic limestone. 



Geology. The range of rocks is rather complete. The sedi- 

 mentary series is represented by two distinct strata of the quartzite 

 and limestone, the latter of which in contact with igneous rocks has 

 developed an amphibolite phase. The first rock found on approach- 

 ing the property is a firm quartzite schist, usually graphitic, dipping 

 55 to 6o° eastward, followed by an igneous rock that is very com- 

 mon in the center of the Adirondacks, known as anorthosite. Here 

 it has been crushed and is somewhat " pulpy " in appearance. Then 

 follows a pure limestone carrying a very small percentage of the 

 usual silicates, but no graphite. Above occurs a quartz-feldspar 

 (the feldspar is orthoclase) schist that likewise is graphite- free. 

 Closely associated with the schist is a dense, hard, green quartzite. 

 Cutting the sedimentary rocks are small dikes or bosses of a fine- 

 grained variety of the augite-syenite. Especially in the vicinity of 

 the diggings this rock has produced contact effects, including the 

 development of large flake graphite. These flakes occur both in 

 the limestone and in the quartzite. 



The next rock is a fine-grained equigranular rock, nearly black in 

 color and rich in garnets. This basic (femic) rock occurs as a dike 

 4 feet wide with a direction N 50 ° W (magnetic) near the western 

 edge of the map. The writer has encountered several similar ones 

 in the Adirondacks but has never seen them described. Under the 

 microscope a specimen consists of augite, hornblende, basic labra- 

 dorite and garnet. Mineralogically it might be classed as a gabbro 

 but the texture is very different. This cuts all the above mentioned 

 rocks in the vicinity. The last rock to be noted is diabase (augite- 

 camptonite), two dikes of which were observed. All the dikes 

 occur along the fault line of the gulf. 



Ores. The graphitic rocks are clearly of two kinds : first, and 

 most important, is the lower quartzite which carries medium to 

 large-sized flakes, but no mica or clay substances. It splits readily 

 but would be a hard rock to crush. The south road crosses several 

 ledges of this quartzite, which dip at a high angle into the hills to 

 the east. There appears to be a good supply of the mineral from 

 what could be seen, although the glacial drift, which is exceedingly 

 thick, obscures much of .the surface. 



The other type of ore has already been mentioned. It occurs as 

 a contact effect where the small tongues of the augite-syenite cut 

 the quartzite and limestone. The farmer who lives in the log cabin 



