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Report of the State Geologist. 



tion, originally blue, but changed to white in those portions bordering on the 

 gneissic and granitic rocks. A third possible view is mentioned by Kemp 

 and Hollick, viz. : that the white limestone is Archean, but metamorphosed 

 along granitic intrusions, and thus charged with minerals, while the blue is of 

 later age. In this main belt no actual contact was found between the blue 

 and the white limestones, although outcrops were found within 200 feet of 

 each other on the road running due north from Edenville and northwest in 

 a general way, along the line of Professor Kemp's section 3. The two are 

 considerably mixed together on the northeast slopes of Mount Eve. The 

 writer, however, found exposures east of the road and one and one-quarter 

 miles west-southwest of Pine Island station, which showed the passage of the 

 blue into the white. In the main belt the blue limestone becomes graphitic 

 and more crystalline towards the white. On the east side of Round hill, the 

 blue limestone is found quite close to the granite and assumes a highly 

 siliceous character, if not actually becoming a quartzite. 



Two great knobs of granite, Mount Adam and Mount Eve, penetrate the 

 limestone. The rock is a hornblende-granite, gneissic in places, and coarsely 

 crystalline, especially at the quarries, the anhedra forming the granite being 

 one-quarter to one-half inch diameter. More or less biotite is present, and 

 augite is common near the margins. The granite is a basic variety, and 

 plagioclase equals or exceeds the orthoclase. Quartz is often common, and 

 contains dusty inclusions. The orthoclase is generally microcline or micro- 

 perthite. The hornblende is black, and is transparent only in the thinnest 

 sections. It is then yellowish green parallel to a, black parallel to I, deep 

 green parallel to c. Brown biotite is usually rare, but it is quite common on 

 Round hill. Allanite, a rare mineral, is abundant in the granite, and, together 

 with pegmatite veins, has spoiled much of the stone for quarrying. Small 

 zircons and titanite are not infrequent. The granite becomes quite gneissic 

 at the north end of Mount Eve, preserving the same mineralogic composition, 

 but the sections show evidences of dynamic metamorphism in the crushed 

 crystals of quartz, feldspar, etc. Sometimes the granite assumes a structure 

 resembling quartz-porphyry. Graphic granite was also found on a knob east 

 of Mount Eve. 



The white limestone is coarsely crystalline, with scattered scales of 

 graphite and, less often, phlogopite. Chondrodite is also present and 

 increases near the contact of the limestone with the granite. 



Contacts. The granite and the white limestone are found in actual 

 contact in several places, and only a few feet apart in others. Towards the 



