53 



of Thetford, Coleraine, Wolfestown and Ham a sudden and marked 

 development is noticed, the rock forming great mountain masses, as 

 seen about Black Lake and in Wolfe. Isolated areas are also found in 

 the St. Francis River basin at Brompton, Melbourne and near Dan- 

 ville, but at no place is there such a great development visible as in 

 Coleraine and Thetford. Other small areas, constituting part of the 

 second or Stoke Mountain anticlinal, exist in the vicinity of Massawippi 

 Lake, in Hatlej, while the areas of Oxford and Bolton have already 

 been indirectly referred to. While traces of asbestus are found at 

 nearly every one of these localities, in many places the indications of it 

 observed ai-e insignificant, though over large areas, it must be con- 

 fessed, the examinations yet made have been but cursory, and these 

 may yet yield this peculiar and valuable mineral in abundance. It is, 

 however, apparent that all serpentine is not equally rich in asbestus, 

 for even in the most productive areas great differences in this respect 

 are visible, and large portions of the belt are made up of what is called 

 barren rock. As a general rule, the different kinds of serpentine, 

 whether likely to be productive or not, can be determined by outward 

 characters, either by peculiarities of weathering or by the texture and 

 color of the mass of the rock itself. At Thetford and in the northei'n 

 part of Coleraine, more particularly about Black Lake, certain peculiar 

 conditions appear to have prevailed which have affected the great ser- 

 pentine masses there, and led to the formation in large quantity of the 

 mineralized form of asbestus, the veins here being not only very numer- 

 ous, often interlacing the rock in all directions, but being also of large 

 size, reaching a width at times of over six inches, while many of them 

 range from two to four inches. In quality of fibre also a marked differ- 

 ence from that found at several other points is apparent by its greater 

 softness and silkiness, which give it a special value for the many piir- 

 poses of manufacture for which it is most in demand. 



In its mode of occurrence asbestus appears to follow closely the 

 principles which are known to affect metalliferous lodes in general. 

 The veins have the aspect of segregation veins, the fibres in all cases, 

 unless disturbed, being at right angles to the sides of the fissure, and in 

 many cases, more especially in those of larger size, the fibi-e is broken 

 near the centre by particles or grains of magnetic or chromic iron 



