The Weiser signal. [volume] (Weiser, Idaho) 1890-1904, 1902-04-02

line gravel, cut by the main track OF
the Oregon Short Line Railway be-
tween Pocatello and American Falls.
plsinly indicate the rapid recession
of the lake levels of this period, its
anal drainage and complete oblitera-
tion by the erosion of Snake river
channel to its present level.
These varying lake levels are well
established throughout the valley
within a vertical range of 1000 feet.
and are now represented by the beds
of conglomerate gravel alternating
with flows of black basaltic lava OF
more recent date Most of these
conelomerate deposits are gold bear
ing, and their sub-aerial disintegra-
ton and erosion by recent stream
action Is doubtless responsible for
the immediate source of the fine float
colors, now 30 generally distributed
through the loose gravel and silt Of
the present river channel and it's
wide fat bars.
''Prior to the inception of the great
foods of black lava that have filled
the upper valleys, the shore lines and
basin area of Lake Idaho were almost
all composed of granite and Palace
zoic formations. These formations
were in placer and quartz gold, as pro-
ven by the higher slopes of the pres
emit drainage basin, and by the number
of island SUBMITS of those formations
that have been left exposed above the
sombre lava floods. The chemical
reaction set up by this combination
of conditions and events would read
lily account for the aqueous origin of
the gold, and it seems to me alto
gether probable that Capt. Turner's
theory is correct.
1.-The quality of Snake river gold
is high and when properly cleaned
minis for 1898 per ounce. The
colors are not only fine, running from
1000 to 1000 to the cent in value.
but they are also fakey in shape,
and are washed down stream with
every summer flood, enriching the low
shifting bars at every short bend in
the stream where favorable condi-
ton for their concentration Is pre-
sented. Bedrock is not important
to the disposition of the values, In
the high banks of loose gravel that
border the stream, as well as in
the low bars and flood planes, the
richest values are represented by thin
lines of gray silt or calcareous sedi-
ment. These lines OF enrichment rep
resent food periods. They are u.s.
ually from a few inches to one foot or
more in thickness, and one to ten feet
apart. The intervening space all
carries gold, but much more spar
ingly.
Subjected to microscopic exami-
nation many of the colors show
rounded edges and concave or cup
like depression in their fiat surface
and quite proportion of them are
coated with sugary incrustation of
silica or some other substance. which
involves the necessity of securing
them in a cleanup barrel or an ar
rastra pan before they will unite
freely with mercury Under sharp
focus OF the microscope all the colors |
show delicate lace like tracery of
fine brown lines, that suggest chemi-
cal reaction. The particles wer-e
probably precipitated from their orig
lnal watery solution of chloride or
bromide OF gold and afterward trans.
muted to metallic by natural process.
"Aside from the above character
istics, under a powerful glass the
fine particles reveal the natural vel
low color and worn, knotled appear
ance of high grade gold nuggets.
The only natural alloy that the gov
eminent assay Office at Boise, Idaho, |
accounts for on shipments of Snake
river bullion is small amount of
silver, and as the fneness of the
bullion after deducting the silver
does not exceed $50, there still re-
mains considerable room for other
natural alloys, which it Is not un-
I,n -,