THE NEW ZEALAND GAZETTE 275

crystalline micaceous clay-slates, with quartz' land. In the serpentine district of Cornwall,
layers and veins, occur.
On either side of this central ridge, the
slates exhibit a more sedimentary character,
alternating with dioritic schists, with amyg-
daloids, with very compact sandstones, ap-
proaching the character of graywacke. As
no fossils have yet been found in those oldest
sedimentary New Zealand schists, it is im-
possible to assign to them their geological
place in a European classification of strata.
The slate and sandstone ridges are flanked
by serpentine.

Below the confluence of the Blarich river
with the Awatere, where the side of the
mountain has slipped with an earthquake rock of
rent, serpentine appears. The Grey Mare's
Tail is a waterfall over a serpentine cliff.
The serpentine extends, in a south-westerly
direction, through the Blarich valley towards
Mount Mowatt, whose south-eastern slope to
a height of about 2000 feet is composed of
serpentine. In the bed of the Blarich river,
Mr. Haast found a piece of copper ore of
the same description as the Dun Mountain
ores.

On the western side, the serpentine occurs
developed to a much greater extent. An im-
mense serpentine dyke of a thickness of
several miles, stretches from the northern
extremity of D'Urville's Island, across the
French Pass, through the Croixelles, by the
Dun Mountain, Upper Wairoa, and is met
with again, on a continuation of the same
straight line, on the red hills, near the Top-
house, on the northern side of the Wairau
Valley. This dyke can thus be traced from
north-east to south-west for a distance of
eighty miles. The strike of the serpentine
dyke is perfectly parallel to that of the slates,
but its eruptive origin is proved by the oc-
currence of a breccia of friction (Reibungs-
breccia) at the line of contact; and the fact
of beds of slate enclosed in it being converted
into hard and semi-vitrified cherts. The ser-
pentine, in its turn, has been broken through
by eruptive dykes of hypersthenite and gab-
bro. The rock of the Dun Mountain proper
is a variety of serpentine, of so novel and
peculiar a character, that I am obliged to
apply to it a new term, and call it "Dun-
pentine." The Dun Mountain district offers to
the scientific geologist a field of unbounded
interest; but I shall perhaps best respond
to the wishes of my audience by telling them
something about the ores of copper and
chromate of iron, which are the characteristic

COPPER.

The occurrence of native copper, red oxide
of copper, and copper pyrites, the principal
copper ores of the Dun Mountain, is by no
means peculiar to the serpentine of New Zea-
land. In the serpentine district of Cornwall,
native copper is found. The Monte
Ramazzo, near Genoa, contains cop-
per in serpentine; and in North America,
the same thing occurs.

I have visited (accompanied by Mr. Hacket
and Mr. Wrey) all the workings of the Dun
Mountain. I could not convince myself of
the existence of a number of parallel lodes,
so as to justify the various names which have
been given, and which appear to designate
different lodes. The Dun Mountain copper
does not occur in a regular lode; by
which I mean a metaliferous dyke of differ-
ent mineral composition from that of the
Mountain. As is usual in ser-
pentine, the copper ore occurs only in nests
or bunches. The richer deposits of copper
form lenticular shaped masses, which,
if followed, may increase to a certain dis-
tance, but then disappear again in a thin
wedge. Where these nests are large and
rich, one alone may sometimes make the
fortune of a mine. The richest found on the
Dun Mountain appears to have been that of
Windtrap Gully, from which pieces of
copper (some of them weighing as
much as eight pounds) were extracted. These
of copper ore occur in the Dun Moun-
tain in one continuous line, as if a rent had
taken place in the serpentine rock, into which
copper had either been injected from be-
neath, or deposited there by the operation of
causes which science is unable to ex-
plain. The green and blue silicates of copper
on surface minerals, which are only of value
showing the direction of the fissure in
greater depth. At a certain distance below
the surface, they disappear entirely, and it is
only by the broken and softened character of
the serpentine that the miner is enabled to
follow the fissure from one deposit of metal
to the other. The occurrence of the best
indications of copper ore on the surface, over
a continuous line of about two miles, affords
good ground for supposing that considerable
quantities of ore are contained in the moun-
tain; but, on the other hand, owing to the
manner in which the ores occur in isolated
bunches, mining operations in such a region
are always attended by less certain profits
than where the metal is deposited in a regular
lode; and I may be allowed to express a hope
that the Dun Mountain may prove to be all
the Nelson people could wish.

In Croiselles and in Current basin, where
mining operations have been carried
out, the indications were very obscure, and
the result has proved that there is no reason-
able ground to expect a profitable copper
mine there. More promising specimens of
copper ore have been obtained from D'Ur-