=36—

of various types of the most highly mineralized rock failed to

yield any gold and showed a maximum of 1.39 ounces of silver.

Prosperity. On this property on Dorreen mountain the main show-
ings are in a spur of argillite that extends into, and appears to
form, a thin shell lying on andesine granodiorite or quartz diorite.
It follows the bedding and strike across the spur which is 500 feet
wide at this point. Both below and above the property, the grano-
diorite, which is extensively exposed, contains only small quartz
gash veins that are mainly barren. The main deposit is exposed
intermittently along a length of less than 300 fect. Over a
length of 50 to 60 feet the deposit is a vein 12 to 18 inches wide,
varying in composition from quartz with moderate amounts of
tetrahedrite and pyrite to massive sulphides. The massive
tetrahedrite carries about 200 ounces in silver and 0.12 ounce in
gold to the ton. One hundred feet higher the vein has the same
width, but is of barren quartz and in a short distance becomes a
series of barren stringers, narrows, and ends against the grano-
diorite. In places the granodiorite crosses the course of the

vein, and in such places the vein is lacking. The evidence

i
,
if

suggests that the mineralization is related to the granodiorite
but that it occurs outside the intrusive, and, therefore, is not
likely to continue to any great depth. Jt is possible, but less
probable, that the deposit is older than the granodiorite and
has been cut off by it.

The rocks along the contact are well exposed and the

mineralization appears to be largely confined to the area in

which the argillite lics on the granodiorite in a relatively thin
shell. Elsewhere the contact appears to dip steeply. Slightly
mineralized showings were observed at a number of other points

on the mountain. Quartz veins; most of them barren or nearly so,