The Cheyenne daily leader. [volume] (Cheyenne, Wyo.) 1870-1884, 1882-09-07
I From tue Mining Record,
WYOMING MINES.
CHEYENNE, WYo.,
An.naH "a I0aN


Sir: In your issue of Jnly
29th. you have an article on "the
general course of assure veins"
which generally, is correct; but |
find that in this region-the cop
per belt ofthe Colorado range
comprising as it does the Laramie
hills stretching northward from
the extreme southern line of wy
Oming on the Union Pacific Rail
road, the general strike of the
veins is nearly north and south,
agreeing very nearly with the
trend ofthe range and these veins,
which by some writers is classed
"male veins III contradistinction
to the east and west veins which
he characterizes as ''female veins"
are invariably the richest.
Here in this magnificent copper
belt, the north and south true fis-
sure veins oundinthe oldarchaean
formation goes upward through
the transition and mctamorphic
rocks whore they are covered up
by the ]cretaceous and later forma-
tons, and cause the immense de-
posits, improperly called fcontact
veins from their general local APP
pearance ut the contact between
the porphyry and the lime. These
~carbonates, s~ilicates and oxides
are really in vulgar parlance,
merely "slop overs ofthe true ifs
sure veins, and down below and
beneath the deposits | am satisfied,
will, at some time or other, when
mining exploration is carried
deeper into the older rocks, eXhib-
it well-detined true assure veins,
carrying the copper pyrites, asso-
ciated with gold and silver.
The surface deposits of the lime
stones, the jaspers and the porphy-
ries, may carry silver, especially
if there are found associated with
them, the chalcocit or copper
glance. This state of things has
been a%bundatly demonstrated at
Hartville in this county, which is
a very late formation on the sur
face, but in the gulches and can
yons of the neighborhood the
older schists and gneissoid rocks
crop out.
In the copper camp west of Chey-
enne, twenty-one miles distant, the
the old archean formation forms
the whole of the rocks and true
assure veins like the Colorado
lodes carrying the copper pyrites
allied with a soluble sulphates,
goes down deep bearing the evil
dences ofpermanency aud contin-
uation to the inner crust of the
| earth.
The east and west veins all over
this country, intersectingthenorth
and south veins, have the same
outcrop of white quartz and iron
ore, but the white quartz are
much more dense massive andcom-
pact and carries free gold in beau
tiful nuggets and sometimes silver
for a distance of fifty feet, but ut
that depth generally it changes
its character, butnot as the cores
pondent (NIr. WILSON, to the Min
ing journal says, to no pay ore.
Its change is to an iron pyrite
which sometimes pays very rich;
below the iron pyrites, galena is
often found in paying quantities
and quality. | cannot agree with
that sweeping denunciation Of
east and west veins, for Colorado
experience has demonstrated hat
very rich mineral has been taken
out ofthcm hundreds OBJECT below
the surface of the rocks.
AT the Queen Sheba mine in the
Colorado lode, is an cast and west
assure vein, but it mtersccts n
north and south vein within n few
feet, which when they cut it, will
develop the copper ore like the
Colorado. | have no hesitation
in saying this, not because | can
see into the rocks more than
others, but | argue from an extern
sive experience of many years in
in these formations, and with the
eye of experience they can be
read like an open book, by just
turning the leaves. | think, the
conclusion, that the north and
south veins, were formed ut an
erlier period than the east and
west veins may be correct, but |
am not quite satisfied on hat
point, to be able to dogmatize
upon it.
FRED. j. STANTON, NJ. L.
Late Ter. Geol. 4 NJ. f. for
Wvo