THE NONMETALLIC MINERALS. 301 



River. The geological horizon is that subdivision of the Lower Silu- 

 rian known as the Quebec Group. The material has also been found 

 in the Laurentian rocks of this region. 



Among the principal areas of serpentine which are found at so many widely scat- 

 tered points, the most easterly yet known is at a point called Mount Serpentine, about 

 10 miles up the Dartmouth River from its outlet in Gaspe Basin. The serpentine is 

 here associated with limestone and surrounded by strata of Devonian age. Small 

 veins of asbestos are found in the rock, but not yet in quantity sufficient to be eco- 

 nomically valuable. West of this the next observed is the great mass of Mount 

 Albert, whence it extends west in a great ridge for some miles. This mass is known 

 to contain veins of chromic-iron, and traces of asbestos have also been observed, 

 but the area has never yet been carefully explored with a view to ascertain the 

 presence of the mineral in quantity, owing largely to the present difficulty of access. 



In Cranbourne and Ware, to the north of the Chaudiere River and in the vicinity 

 of that stream between the villages of St.' Joseph and St. Francis, seVeral small 

 knolls are seen, in all of which small and irregular veins are visible, but apparently 

 not in quantity sufficient to render them economically important, at least in so far 

 as yet examined. Further to the southwest, in Broughton, Thetford, Coleraine, 

 Wolfestow and Ham, a very great development of these rocks is observed, forming 

 at times mountain-masses from 600 to 900 feet above the surrounding country level, 

 and presenting very peculiar and boldly marked features in the landscape by their 

 rugged outlines and curiously weathered surfaces. The large areas of this division 

 terminate southward at a point termed Ham Mountain, a very prominent peak of 

 diorite which marks the extremity of the ridge. In this great area, which we may 

 style the central area, asbestos can be found at many points in small quantity, but at 

 a comparatively few does it occur in quantity and quality sufficient to warrant the 

 expenditure of much capital in its extraction. 



The third area, regarding that of the Shickshocks as the first, begins near the 

 village of Danville, and may be styled the southwestern area. Thence it extends 

 through Melbourne, Brompton, Orford, Bolton, and Potton, in a series of discon- 

 nected hills, to the American boundary, beyond which the continuation of the serpen- 

 tines can be traced into Vermont. In these areas, with the exception of the peculiar 

 isolated knoll near Danville, the asbestos has, as yet, been observed in small quantity 

 only, and generally of inferior quality. Large areas of soapstone are found at points 

 throughout the area, and the associated diorites have a large development. It must, 

 however, be said of this section, that considerable areas, whose outcrops can be seen 

 along the roads which traverse the district, are concealed by a dense forest growth, 

 and the true value of such portions must, for some considerable time, be largely con- 

 jectural. In fact, until the forest and soil are completely removed by the action of 

 forest fires, as was the case at Black Lake and Thetford, the search for asbestos is 

 likely to prove difficult and unsatisfactory. It is, however, very evident from the 

 studies already made on this interesting group of rocks in Canada, that all serpen- 

 tines are not equally productive a fact very evident even in the heart of the great 

 mining centers themselves, where large areas of the belt are made up of what is 

 known as barren serpentine. As a general rule, however, the rock likely to prove 

 asbestos-producing can be determined by certain peculiarities of texture, color or 

 weathering. 



At the Thetford mines, and in that portion of Coleraine lying to the northeast of 

 Black Lake, certain conditions favorable to the production of asbestos appear to 

 have prevailed, and have led to the formation of numerous veins, often of large 

 size, which, in places, interlace the rock in all directions. These veins range in size 

 from small threads to a width of 3 to 4 inches [fig. 11], and in rare cases even reach 

 athickness of over 6 inches. [See large Specimens Nos. 72836 and 61348, U.S.N.M.]. 

 The quality of the fiber, however, varies even in these localities, and while much of 



