456 REVIEWS—GEOLOGICAL SURVEY OF CANADA. 
“The rock of the hill is such as has usually been called talecose slate; but 
though unctuous to the touch, analyses by Mr. Hunt of slates of a similar charac- 
ter in other parts of the vicinity of Harvey’s Hill, have shewn that instead of 
magnesian they are aluminous, and that they should rather be designated mica- 
ceous, or, as he has called them from their lustre, nacreous slates. They are in 
general whitish, or light grey, and are often thickly studded with chloritoid. 
These slates are interstratified with bands of a darker colour, more resembling 
clay slates, and the darker appears to prevail over the lighter colour at the mouth 
of the adit. The dip of the strata appears to be from N. 19 W. to N. 65 W. 
with an average slope of between fifteen and nineteen degrees. The bearings of 
eight of the quartz courses are from N. 15 E. to N. 35 E. while one of them runs 
N.75 W. They all underlie to the westward at angles varying from fifty to 
nearly ninety degrees, and it would thus appear that none of them coincide with 
the strata either in dip or strike. 
“ During the present year (1859), Mr. Cushing has made an arrangement for the 
working of the copper ore on his property, and under it Mr. Louis Sleeper, of 
Quebec (who has heretofore been engaged in mineral explorations in the County 
of Megantie, and in testing for different mining companies by trial-shafts and 
other excavations, various quartz courses marked by copper ore in the townships 
of Inverness and Leeds), commenced mining in the Acton copper ore, on the 23rd 
of September last. After several weeks had been spent in the excavations, I had 
an opportunity of visiting the mine, and of spending several days in the examina- 
tion of the facts observable in the natural exposures of rock in the neighbour- 
hood, as well as those brought to light by the excavations. 
“The mine is just half a mile to the south of the Acton Station of the Grand 
Trunk Railway. The road to it is over a marshy piece of ground, and it is crossed 
by one or two low mounds of yellow sand. At the end of the road, a hill rises 
to the height of about 105 feet above the marsh, and descends to a marsh on the 
other side. It stands on a base of a quarter of a mile in width, and for nearly 
one half the distance is composed of a sub-erystalline magnesian limestone dip- 
ping to the north-west, with an inclination varying from thirty to forty degrees. 
The limestone is light grey in fresh fractures, and weathers to a dull pale yellowish 
tint on the exterior. It is in some parts studded with coneretionary nodules, con- 
sisting of concentric layers of carbonate of lime, with a transverse fibrous struc- 
ture. The exterior of these is of a botryoidal form, and the layers are in some 
places partially replaced by chert, preserving the fibrous structure. These nodules 
very much resemble corals, but they also resemble some concretionary forms of 
travertine, and the occasional intercolation of magnesian layers in the nodules 
makes it probable they are the latter. As stated by Mr. Hunt, the limestone of 
the hill is intersected by several small veins of quartz; and one of them, more 
conspicuous than the rest, carries traces of the yellow sulphuret of copper and of 
galena. The mass of limestone visible, extending a short distance beyond the 
summit of the hill, has a thickness of about 270 feet. It is divided into heavy 
beds, in which irregular masses of chert are disseminated in unequal quantities 
in different places, being most abundant towards the bottom. 
“The summit of the limestone from the north-eastern corner of the lot, pro- 
