The Origin of the Gold
Written expressly for the Klondike Nugget by J. Sloan Johnson.
The gold on Bonanza and Eldorado creeks originated principally in the track
of the glacier that parallels those streams. The glacier traveled from a
northerly direction following a formation commonly known as prophyritic quartz,
which is about 800 feet wide and which lies about 150 feet higher than the
present bed of the two creeks mentioned.
The formation over which the glacier traveled is composed principally of
igneous rocks mixed to a certain extent whith metamorphic rocks. The
formation of the gold belt is very similar to that of California, and the gold
found in the alluvial deposit has at some time been connected with the dikes of
dissimilar rock and with the quartz veins and stringers crossing and connecting
with each other throughout the gold-bearing formation.
We will mention a few formations crossing the great dike covered by the
gravel. Commencing opposite No. 25 below on Bonanza, on Fox gulch, we find
small stringers of rhyolite crossing the main formation at right angles.
On 19 gulch we find an intrusive dike, commonly known as pegmetite; this occurs
on the bench claim opposite the upper half of No. 3, left limit. On the
upper half of No. 3, Magnet gulch, we find the pure porphyritic quartz, largely
interlaced with quartz stringers. On the benches opposite No. 12 below,
Bonanza, mica schist intrudes itself into the main dike and forms the bed rock
of the benches. At No. 5 below Bonanza, we encounter the graphite shists
crossing the benches at right angles. This is found in great abundance on
Passing to Big Skookum, we find a cross section of choloritic shist.
This formation traverses Gold hill and has much to do with the rich deposit of
gold found there.
Between No. 13 and No. 14 Eldorado, we encounter a diabase dike crossing the
On French hill we have black slate, talcose slate and plumbago shist.
On upper Eldorado, porphyry occurs quite frequently, together with mica shist
and plumbageo shist.
These formations are intrusive, and at the point of contact with the quartz
veins and stringers form what are known as quartz pockets. And when the
gravel is removed from the hills and the bedrock exposed, the pocket miner will
then uncover the richest pockets the world has ever seen.
French hill, Gold hill and Cheechako hill give evidence of wonderful pockets
in the quartz. The glacier wore the formation down and turned the pockets
inside out and deposited the gold on bedrock. The pick and drill will
delve into the quartz stringers and find pockets of fabulous richness when the
pocket miner can see the formation and find the stringer on which to sink.
A peculiar feature of the coarse gold streak in the high benches is that
native quicksilver is found from Fox hill to Gold hill. Also we find along
the line of the glacier drifts, especially about the sixties below on Bonanza,
many specimens of casseterite or stream tin. This follows with the heavy
gold. This is very rich in tin, assaying 67 per cent tin. We think,
judging from the peculiar geological structure of the country that the great
wealth of Bonanza and Eldorado districts lies under the alluvial deposit of the
high benches, and when transportation companies will sell powder and steel at a
reasonable profit, and the government be more liberal in its policy, then the
resources of this country will be developed. We do not look for milling
quartz, but the wealth of the country lies in the bull quartz or pocket, where
it makes a crossing with other veins or dikes; and instead of heavy machinery
being necessary, the miner with a hand mortar can separate the gold as we do in
The Klondike Nugget,
November 1, 1899.