POSITION. 393 



quartz is well developed along the east part of St. Albans, Swanton, and Fairfield, but is 

 succeeded gradually by a novaculite schist and limestone in Sheldon and Franklin. The 

 latter is especially abundant in the west part of Franklin. Between the Union and Brick 

 Churches, in Sheldon, there is a great development of conglomerate. In the north part 

 of Franklin, for about three miles, it would be difficult to name the rock, as it is a dirty 

 massive compound between limestone and novaculite schist. 



We have made no estimate of the thickness of the talcose conglomerates, but know 

 that they must be very thick. They must be 2,000 or 3,000 feet thick at the least calcula- 

 tion, where they are fully developed, as in the northern part of the State. We suppose 

 that this belt of rocks includes the Sillery sandstones of Canada. These are estimated at 

 4,000 feet, in Canada. 



No fossils have been found in the talcose conglomerates. 



Mineral Contents. 



The minerals of these rocks are very few. The most common, and in some places they are quite large, are 

 veins of milky and transparent quartz, with which there may be associated large crystals of quartz. We 

 noticed such specimens in Westford and Fairfax. 



Some of the fine veins of red hematite in Fairfield belong to these rocks ; though most of them may be 

 referred to the talcose schist. 



In Franklin there is some novacul,te though of inferior quality. 



Another mineral is dolomite, which passes into a rock. 



G-eological Position and Equivalency. 



The talcose conglomerates are the continuation into Vermont of the upper part of the 

 Quebec group and the Sillery sandstones of Canada. The Canada Survey now regard 

 them as lower Silurian ; but formerly considered them of the age of the Oneida conglom- 

 erate of the middle Silurian. Prof. Emmons, we suppose, would class them among his 

 Taconic rocks, and therefore as older than Silurian. 



The view that we shall present of the age of these rocks is, at present, less definite 

 than the others, and will eventually, probably, coincide with one of the first two theories. 

 If we were to decide stratigraphically, we must say that it is newer than the Georgia slate, 

 since it invariably overlies it, unless the dip be inverted. It is the eleventh belt of rocks, 

 overlying the Laurentian rocks of Northern New York. 



We regard this belt of rocks as associated with the quartz rock of the southern part of 

 the State. It may be of identically the same age, or in other words, the strata of quartz 

 rock pass gradually into strata of talcose conglomerate. It is for this reason that we have 

 used the same color to represent both the quartz rock and the talcose conglomerates, upon 

 the Geological Map. 



As the thickness of the conglomerates is greater than that of the quartz rock, so the 

 synchronism of the two may not be perfect. Some of the conglomerates may be newer, 

 and some may be older than the quartz ; but we think the same general age may be as- 

 cribed to both. 



It is in this belt of rocks that the great metamorphic agency is fully developed, which 

 has so altered the rocks of New England. Hence we have no fossils to guide our way, and 

 it is^exceedingly difficult to progress satisfactorily without them. But future discoveries will 

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