GEOLOGICAL REPORT
ON
ASBESTOS,
AND ITS INDICATIONS, IN
THE PROVINCE OF QUEBEC,
CANADA.
London:
E. FORSTER GROOM, 15, CHARING CROSS, S.W.
1889.
[All rights reserved.]
HAVING been called upon to make a close and careful examination of thegeological formations in the eastern townships of Garthby, Wolf'stown,and Coleraine, situated in the province of Quebec, Canada, I gavespecial attention to the distribution of the Asbestos-bearing rocks(serpentine), which have been, in my opinion, heretofore only partiallytraced. Perhaps this was owing to the difficulties which had to beencountered from the thick undergrowth which in many places rendered it[2]almost impossible to penetrate sufficiently in order to make a truereport as regards the "existence," "location," and "association" ofthese rocks.
Admirable reports have been written by R. E. Ellis, LL.D., Dr. Hunt, andothers, on the origin and distribution of the serpentines, and have beenfully discussed and ventilated. Still, though various opinions have beenexpressed upon the subject, they appear to differ in many respects. Imention these facts as possibly one inexperienced or unacquainted withthe country might consider it strange that a thorough examination of theAsbestos properties had not been followed. Yet the causes I havementioned above, as well as the difficulties I had to contend withduring the months of heavy snowfall, lead me to believe that myconfrères (geologists) were disinclined to follow up a correct andactual prospectus of these valuable serpentinous localities.
Before locating, or going into details of these classes of rock as amineral repository, I intend to treat on the subject as regards their[3]mode of existence and origin.
Serpentine is diffused under the head of "metamorphic rocks," while, inthe widest sense, according to Studor and others, mineral metamorphismmeans every change of aggregation, structure, or chemical condition,which rocks have undergone subsequently to their deposition andstratification, or the effects which have been produced by forces otherthan gravity and cohesion.
There fall under this definition the discolouration of the surface of,for instance, black limestone, by the loss of its carbon, the formationof brownish red crusts in rocks of limestone, sandstone, manyslatestones, shales, granite, &c., by the decomposition of compounds ofiron, finely disseminated in the mass of the rock, the change in rocksconsequent in the absorption of water, and the crumbling of manygranites and porphyries into gravel, occasioned by the decomposition ofthe mica and felspar.
In its more limited sense the term "metamorphic" is confined to those[4]changes of rock which are produced directly or indirectly by agenciesseated in the interior of the earth. In many cases the mode of changemay be explained by our physical or chemical theories, and may be viewedas the effects of temperature or of