96

In addition to the three main ore occurrences, magnetite ore is present
at a number of localities. Only one of these occurrences was more than
cursorily examined by the present writer. This place lies a few hundred
yards north of the Prescott mine. At it (See Figure 19) isolated outcrops
of magnetite project through drift in three places, of which the westernmost
has an area of 9,600 square feet, but all of this may not be underlain by
magnetite.

The various minor occurrences are described by McConnell as follows:

“West of the Prescott mine, a number of magnetite lenses of moderate

sizes occur along the diorite-lime, and farther on the porphyrite-lime
contacts, the larger having a length of 90 feet and a width of 20 feet.
Lenses have also formed at a few points along the small, outlying diorite
stocks and dykes. A lens 57 feet long and 20 feet wide occurs at one
point, forming the continuation of a diorite dyke. The magnetite in
this lens is remarkably free from both sulphides and non-metallic im-
purities. ;
North of the Prescott mine, the lime-diorite contact is exceedingly
irregular, consisting of a succession of spurs and bays. Three large and
several small lenses of magnetite occur in one of the limestone bays. (This
is the locality of Figure 19, See above.) The most westerly and largest of
these has formed entirely in limestone at a distance of 100 feet from the
tip of the diorite spur. It has a length of 250 feet and an average width of
about 50 feet. The second lens has a length of 160 feet, a width of 40 feet,
and has formed along the contact. The third lens has developed partly
in diorite and partly in limestone and has a length of 200 feet and a width
of about 70 feet. The diorite southeast of this lens is altered and replaced
for some distance by epidote, garnet, and grains and bunches of magnetite.
No work has been done on these lenses except the excavation of a small
pit at one point. The ore, judging from the surface exposure, is of superior
quality, and the percentage of sulphides is very small.

Southwest of the Prescott a mineralized area in the quartz diorite,
about 75 feet across, is exposed in a cut on the tramway (since destroyed)
from the mine to the coast. The area contains a narrow lens of magnetite,
but consists mainly of epidote, garnet, and small bunches of magnetite.
The percentage of sulphides present, mostly iron pyrites, is high.

The Paxton ore-body oceurs at the southern extremity of a long,
altered area consisting mainly of epidote, garnet, and magnetite, in grains
and bunches, situated on the south along a diorite-porphyrite contact.
To the north, the two intrusives are separated by a limestone spur and the
altered area divides into two portions, the easterly one following the por-
phyrite and the westerly one the diorite. The latter spreads southward
at one point into the diorite for a distance of 500 feet. It contains several
lenses of magnetite of good quality from 50 to 75 feet in length. The
easterly branch also holds some moderate-sized magnetite lenses and near
its termination small lenses of chalcopyrite, several of which have been
mined, occur in the limestone.

The lime-diorite contact farther to the north is marked at intervals
by small magnetite lenses and areas of the alteration, and at one point the
diorite at some distance from the contact is completely replaced by a mass
of secondary minerals. The replaced area is crescentic in shape and has
a length of 300 feet. It contains two magnetite lenses, each about 60 feet

in length, and numerous small aggregates and bunches associated mainly
with epidote and garnet.