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State of Vermont. It is possible that much of this serpentine may be 

 the result of alteration from dolomitic rock, or from slates which con- 

 tain dolomite ; whereas it is clear that much of that found in Thetford 

 and Coleraine is an alterative product of dioritic eruptive rock, rich in 

 olivine or some allied mineral. 



The rocks of the central or Coleraine area differ as a whole from 

 those just described in being, as a rule, much more massive, and occur- 

 ring in large areas. They have associat-d with them deposits of chromic 

 iron and of magnetite, as well as of asbestus. Large areas of steatite 

 or soapstone occur also about Ham Lake, and mining for nickel was 

 carried on in this vicinity many years ago, the quantity of this mineral 

 obtained being, however, but small. The country occupied by these 

 rocks is generally rough and uninviting from the agricultural standpoint, 

 and the whole area from Ham Mountain to the northern terminus of 

 the main belt in Thetford or at the Bull Mountain in Adstock is of this 

 description. In character of rock the serpentine presents several varie- 

 ties. Portions are hard, reddish brown weathering and very siliceous, 

 as seen in much of that in the townships of Wolfestown and Ireland, 

 and even in the Coleraine ridge south of Black Lake and about Lakes 

 Caribou and Little St. Francis. In this hard siliceous serpentine, 

 asbestus very vaiely occurs, and when present is mostly of impeifectly 

 developed fibre in short and gashy veins. Occasionally, however 

 s eamy partings are found which at first glance and at a distance 

 pi'esent somewhat the aspect of asbestus veins, but on closer examina- 

 tion reveal the existence possibly of a small parting of fibre, or some- 

 times only of a seam of serpentine. In certain portions of the belt these 

 seamy partings are quite numerous, and by some prospectors are sup- 

 posed to indicate the presence of workable veins, on the general princi- 

 ple held by many practical miners, that a vein of mineral matter always 

 becomes larger as it is followed downward, a principle of such peculiar 

 application that its absurdity should be apparent to anyone who has 

 ever thought a moment on the subject. 



Passing beyond or to the north-east of the great masses of serpen- 

 tine in Thetford and Coleraine, detached masses, knolls, and sometimes 

 bands of this rock crop out at intervals. These are well seen near the 

 Chaudiere River, both in the Bras de Sud Quest and in the Des Plants 



