REVIEWS—GEOLOGICAL SURVEY OF CANADA. 461] 
Leeds, precisely resembles that in which it occurs in the bituminous slates of 
Germany, and it is only the circumstance that the facts known in connection with 
the Canadian deposits are yet too few to give entire confidence in the persistence 
of similar conditions over a great area, which should moderate the expectation of 
an important result. “As the copper in the beds is probably contemporaneous 
with them, it would of course be antecedent to that associated with the courses 
of quartz, the fissures holding which, it is unnecessary to state, must have been 
formed subsequent to the strata in which they occur. The copper in the courses 
was probably derived from that in the beds, and though the former, not only in 
Leeds but in other parts, may in many cases prove to be economically unavailable, 
it may yet be serviceable as an index to the position of available beds, and ma- 
terially aid in their discovery. The copper-bearing quartz courses, from contrast 
of colour, are much more conspicuous than the copper-bearing beds; and though 
the latter, from the undulations in the strata, might be brought to the surface in 
many places, they would not readily attract the eye, unless from marks connected 
with the strata more prominent than the copper ore itself, which at the surface 
will often have disappeared from the influence of the weather. At Harvey’s Hill, 
the soapstone underlying the lower cupriferous bed, might prove a serviceable 
mark by which to trace the copper ore on the surface. The soapstone known to 
crop out at a certain distance beyond Fremont’s shaft, though its accompanying 
ore has not been remarked, could, in ail probability, be followed for a considerable 
distance on the strike, with very little difficulty. Should the cupriferous charac- 
ter of the upper part prove continuous, which appears to me very likely, the 
existence of a valuable copper ore deposit might thus be established as probable 
at a very small’expense. Cupriferous beds would, of course, be subject to the 
accidents of dislocation affecting the strata in which they are enclosed. One of 
these appears to affect the Harvey Hill bed, where the lower shaft intersects it. 
At this spot the copper ore suddenly ceases, and a mass of quartz presents itself, 
cutting a part of the stratification iu a nearly vertical direction; while a little to 
the eastward, the inclination of the copper-bearing bed suddenly increases from 
nineteen to thirty-nine degrees. These circumstances combined, appear to me to 
indicate a dislocation, with a down-throw to the northward. 
“The discovery of copper ore, subordinate to the stratification of the maguesian 
group in Upton, Acton, and Leeds, of which the last two instances, and perhaps 
the first, afford quantities economically available, invest the traces so widely 
spread in connection with this group in Eastern Canada, with more importance 
than they previously possessed. These traces are not confined to the more crys- 
talline and altered parts of the deposit, but extend to the portion which is so far 
unchanged as to be marked by characteristic fossils, and the ores being found to 
occur mingled with the original sedimentary matter of the beds, there is no 
geological reason why such traces may not lead to the discovery of economical 
quantities of the ore at Quebec and Point Levi, as well as in other parts. There 
are dolomites, however, in a lower part of the Silurian series than this group, and 
both these dolomitic groups are found to exist below Quebec, on the St. Lawrence, 
—the one on the north side, at Mingan; and the other on the south side, all the 
way to Cape Rosier, and in various islands near both sides; and the fossils being 
