Idaho semi-weekly world. [volume] (Idaho City, Idaho Territory) 1875-1908, 1879-08-15

by quartz miners and prospcctors, who
will find II a piece of valuable informa-
tion.
s.fi1imneys and sfriations,v and the
Relation or the Eruptiye Rocks to
Ore Deposits.
Without entering into any general dis
cussion Of the opinions OF scientific men
as 10 the origin or source Of the ore he
posits that contain the precious metals, |
propose 10 make simple statement OF
facts as have observed them.
PROF. RIA, mond says: I'VE have yet to
find the educated gneer who admits the
correctness Of Mr.. Clayton's proposition,
ar The text book. or essay, or address, not
produced BIZ Mr. Clayton, who endorses II.
And our own observation, so far lis IL goes,
and that Of others with whom we have
conyersed, fails to show the existence Of
such law as he ). pposes to exist
Now let us examine ihr facts as OBJ
served by one who has spent most Of his
life in the field In contact with the iacts.
Ia the State of California ] observed that
the richest ore in the true veins was found
In chutes or oh mneys OF limited extent
on the horizontal Inc; but more or less
persistent To the deep, and In most cases
lode. | also observed that the tenure Of
gold was 50 light in ihe majority of quartz
veins that Il was difiicutto follow the best
pay streak, or chimney, by the appearance
OF the quartz TO the sight. Hence, the
work would be extended into barren
ground, causing loss, and probable aban-
donmcnt of valuable property. ! had
often observed with great interest the
.gtriaei' ON the walls OF VEINS and II oc-
CURED TO me that these lines of movement
had Il Significance heretofore unsupported.
For two or three years l made careful
study Of every mine | visited, that had
been worked 90 any considerable extent
to see IL the rich orerhutes and The .striae"
ON the walls were c0incdent In their
downward trend to the deep. The result
In ever instance was that they were, IN
most part, coincldent in direction. ! then
ventured topublsb, Gn 1866 The result Of
my observations, In an article entitled
s'lIints to Prospectors.' They, at least,
understood and appreciated the hints
given, and many an old abandoned mine
was rc.entcred and explored in the light
Of these new facts, and the pay cllutes re-
covered. This was done so often that the
facts became generally recognized by in
telligcnt miners throughout the State.
extended my study of these interest
ing facts over a large part OF the state,
from Butte county To Kern county inclu-
sive. examined veins in granite, slate,
am, greensboro; veins cutting across the
states; veins having course aud dip with
the states, ms we'll rs veins In lines of con-
tact between two geological formations
Of different characters; veins IN eruptive
rocks, aud veins in scdimentary rocks, all
tar
viz: the rich ores confined to one or
more chntes, or chimneys, Iitchiug down
Ia directions coincident with the Lines of
movement as shown in most part by the
"strlueN on the walls inclosing the veins.
The series OF observations, with the re-
suits above stated, naturally led me to the
Investigation of other phenomena Of equal
interest | found the metal hearing veins
more numerous in the neighborhood of
the eruptiye, or plutonic rocks than else.
where; she Il lie and shales more crysla.
line, the evidence of chemical activities
more obvious, aud the tenure of metal
GENERALLY greater than in districts undis-
turbed by the election of plutonic rocks.
Near these centefs of local dism bance,
two or more distinct systems of assure are
often found crossing each other; such sys
tenn having an approximate parallelism in
course and dip, and many other features
IN common, such as structure, character
istie minerals, Ne. that enable one 10 read
ily distinguish one system of veins from
the others In such localities the pitch
or downward trend of the chimneys Of ore
in one system of veins may differ widely
from the direction OF the chimneys In the
other system. But take such system of
veins separately. and the pitch of the ore
chuLes are approximately The same in all
the veins OF that system throughout that
district In most localities OF this char
aegcr II Is evident that each vein system Is
of diserent geological age, and that the
forces producing them acted from differ
eni directions. A careful study of the
erupiiye dikes, or other plutonie rocks in
tie neighboGhood, will give a clue to the
active causes that produced the assures, !
and Oiled them with ere.
The relation OF the cruptive rocks TO ore |
deposits has not been investigated as t or
oughly as its Importance demands. When |
fllis is done, and we'll done, unless | am |
greatly mistaken, true mineral veins will |
lie found ta occupy great geological |
faults and assures due tn local centers
of plutonic action, rather than to ''conti-
mental upliits, and depressions due to
gravity"
/ am not acquainted with any import
ant mining district, or any GREAT MINE
that IS not more or less intimately connect
Ia with cruptiye siikes, or ore lines Of
great geoiogi al faults. For fear that this
...,st.,,t ,,,ax, I,a canfroverfad or nttea