Reviews and Notices of Books. 219 



nineteen per cent., and from the Huron Copper Bay mine, pro- 

 bably about 1300 tons; making tbe total quantity obtained by 

 the two mining companies in that year about 3000 tons. The 

 deepest working on the West Canada Company's ground is about 

 twenty fathoms. The number of men employed on the Welling- 

 ton and Copper Bay mines is supposed to be about 260. All of 

 the ore raised by this Company is sent to the United Kingdom. — 

 Jluronian.''^ 

 *' Acton Mine, Acton, lot 32, range 3, 



W. H. A. Davies and C. Dunkin, Montreaiy 

 " The ore of the Acton mine occurs in masses subordinate to 

 the stratification, at the summit ofa band of greyish white and red- 

 dish grey compact sub-crystalline dolomite, from 200 to 300 feet 

 thick, belonging to the base of the Quebec group. The dolomite 

 is divided into two massive beds ; it is associated with a good 

 deal of chert, and encloses mammillated fibrous concretionary 

 forms, resembling those of travertine. At the summit, the 

 dolomite often terminates in a breccia or conglomerate, with an- 

 gular and rounded masses of limestone, intermingled with ragged, 

 irregular masses of chert. In many places the dolomite is mark- 

 ed by the occurrence of the yellow, variegated and vitreous sul- 

 phurets of copper, which are in patches, running with the strati- 

 fication. In the neighbourhood of these, many veins, and strings 

 and veins of quartz interset the rock, in various directions, and 

 hold portions of tbe sulphurets of copper. The copper ores which 

 often contain native silver, appear to be more abundant in the 

 upper part of the rock. At Acton the conglomerate is separated 

 from the main body of the dolomite by between eighty and ninety 

 feet of dark grey or black slates, intermixed with diorite ; in these 

 the conglomerate lies in large isolated masses, running parallel 

 with the summit of the main body of the dolomite. On the open- 

 ing of the mine, the sulphurets, where most abundant, appeared 

 partially to surround them ; in some parts constituting the paste 

 of the conglomerate. As the work proceeded, many slips and 

 dislocations, of no great magnitude, where found to cut the 

 strata. Some of them appear to run with the strike, and others 

 in two parallel series, oblique to one another. These disturb the 

 regular continuity of the copper-bearing bed, producing apparent 

 undulations in the dip, and causing the diorite and the limestone to 

 protrude into the copper ore, or unexpectedly to interrupt one an- 

 other. The ores were found to be concentrated in three large masses, 



