The Emporia news. [volume] (Emporia, Kan.) 1859-1881, 1880-03-19
rresistible drnamic force. and much cap.

AAAAt-tslt auG t4St-h DGlC% 14SSc DIlAin
from igneous and volcanic agencies
would contain gold and silver in paving
quantities. and thai we might treat with
profit the vast lava beds Of the Pacific
slope.
fhe innate greed for gold would have
changed Herculaneum and Pompeii
from fields of ancient relics TO mining
centers, while in mining parlance ''chini-
neys, blow outs and the like, instead
of being applied TO the results of chcmi-
cal clanges, would be more appropriate
ly applied to -12ina, Fesuvius, Aeowa-
qua, Pnpocatapeti aud other volcanoes.
The igneoGs or burnt condition of the
ore IN mines IS due TO chemical meta
morphisin. and only extends as deep
Is surface water and ath1osphey
or the meteoric agencies containing
oxygen and carbonic acids have pene
traied the ore bodies. The depth to
which such changes may take place de
ponds on various conditions, some of
which are, texture of ores. unfractured
formation, including country rocks, and
whether they are assures, lodes, or other
kinds of ore deposits. These chemical
changes and metamorphism, render the
mineral less rcbellious or refractory-to
some extent IL Is desulphuriZed, and, If
gold ore, II can ordinarily be treated
by amalgamation or the common stsimp
mill process. Fissure veins are seldom
found TO have undergone change deep
er than 40 10 100 feet-hence it is unsafe
to erect stamp for II assure vein until a
depth beyond the action of the metoric
elements has been attained, to ascertain
if the ore in its original state is of free
milling quality. Monuments of eXpen-
siye folly IN this regard are quite numer-
Gus, but 1t is to be hoped that mining
biologists will emulgate a greater pro-
ficiency in this branch of their import
ant and highly responsible calling, so
that capital. which at present tavors
Americas soon 10 be most lucrative in
dustry, may be guided from snch disas-
trous investments.
Gold and silver mines are the results
of aqueous depositlons and may be class
flied AS assure veins, contact lodes and
deposits.
TRUE FIssERE VEINS.
Upheavals of the earth's surface in ex-
tensive ridges and plateaus are caused
by lateral contraction of the earth's crust
while cooling, and erosion generally per
forms the rest of the mountain making
but during the process of contraction
and upheaval, cracks, fracturesior assures
are made in the granite or Other print
tive rocks. These assures are imme
diately filed with water and subsequent
ly with vein stuff in manner made
palmer further on. But right here if one
stops to think, he can readily imagine
how "horses," keys and wedges, could
have been dropped and lodged IN the fis-
sure before the ore body was formed
therein. So also may breaks" SLIPS"
faults" and other irregularities met with
in assures, be accounted for.
FIt,f. Granite and other DrimitIyn r,,p lie
formed during the first period of the
earlh'S couling, when the water now sur
rounding it wgs in Il semi-gaseOus state
are of the aquaigneouS OF scmi-aqueOus
character, and will be found IN our analy-
sis to contain the precious metals in the
most minute particles.
The next period of geologic Il crust for
nation after the first or toZoic (having
no auimals) was the ancient and most
primitive animal perion, or the palace
zoic time. The temperature had fallen
sufficiently to allow gasses TO assume "A
! liquid form. No mountains are yet
formed. the water entirely surrounds the
earth Ia a depth of al least three miles.
! The primitive rocks are disinteTated Oh
! dissolved, and held in fine fragmentary
! particles throughout the thermal waters
! which have aided in setting free the met
| ais preparatory TO filling the assures
when mountain making shall begin
| The cracks are then charged with the 81
| iicla and other remains from the print
| tive rock with the different metals most
| ~ by scdimentaTy depositions from
above, but panty from infil;ratiOn
| When subsistence takes place, so thai
water carrying free oxygen and carboniC
| acid reaches The vein matter, chemical
! changes begin and the various matamGr
pnic conditions are prodaccd.
CONTACT L0DEs.
Nearly all rocks formed after am
above the coz 'ic rocks are both frar
mcnt#ry and scdiml nt.sry-formcd fruH
! pulveriZed Particles ct other rocks ans
deposited ia the bottom of The ocean
| CUrals. chalks and limestone are partly
composed If the remains of marine all
mails.
The first part of the paIaeozic age
called the sIluriam, was prolific in dol
! matte magnetism limestone and sand
! stone uuartZiteS and the predominant
animals were trilobites and lingulae, a
shewn by their fossil remains. Their
would he times when the waters ant
other rock making agencies would b
conducive to sandstone formation, thel
shales and states. Then animal life wa
energetic, then lime beds were formed
then a period would pass that would b
conducive to mineral dispositions. I'll
LAYERS between which the bed of mincra
is deposited are called the contact. Tn
thickness of the ore body is not AWAY
: uniform-the departures may be cause,
by some slight npheaYel of the foot O
under rock, or an uneven floor caused b.
currents and other agencies. The pa
laeoZoic was the great mineral deposit
ing are of the world. However, som
4
ages. But tins law is observed. Tha
the richest precious metal ores were dc
posted along the line of, or near wher
mountain chains were formed, seeming
" proving that the heat and possibl
fractional electricity cngendered i
mountain making, were necessary (
precipitate the gold and silver.
DEPOSIT MINES
, NAV be classed as bodies of ore wit
both walls obliterated. leaving only tn
. mineral in a broken up mass deposit
; made by mineral springs-and placer.
which are gravel and wash materia
containing gold in small quantities {
nuggets brought from veins and lodcs.
THE CARBONATE FORMATION.
+ Both in fissure veins and contact lode
where no lime exists or surface water
: containing lime, there will be found II
surface wafer has penetrated the ore wi
= he changed from metallic sulphides I
, metallic oxides, and if gold ores the @ol
| will be free.
l The principal mines of the Blac
/, Hills are contact lodes with slate an
e felsite as the contact, hence the ores al
! greatly oxodIZed but not carbonate
? But at Leadville the contact is of MAJ
} nesian dolomitic limestone and micac
: Gus felsite. Upheavals, subsidences an
c extensive erosion have taken place an
+ left the formation tilted, the saline Sc
e waters have reccdcd and left the contac
:, near the surface. The atmosphere
D agencies combining with the lime ca
!, | donated the ores which were original
y formed rs sulphidcs.
/ SOME INDICATIONS THAT LEAD To TIL
/ DISCOVERY OF CONTACT LoDEs
4 Because mine is a assure vein it dot
c not follow that its vein stuff is rich
J. pay mineral, and this is equally true
; contact iodes While assure veins al
z usually found in the primitive rocks
c | Colorado. the contact lodes generally o
4 cur between the lower layers of the y
"A laeoZoic rocks. The upper layers a
y the carboniferous rocks that contain ii
l. great coal beds of the earth.
d After the formation of these rocks {
If upheaval of the land and subsistence
d the wafer takes place-erosion begiI
e work, the sedimcntary rocks are woI
Y off the highest ridges down to the prim
5 tive formations and the assures are e
Ii posed. From the backs OF the fissur
and from the contact the gold and silv
a are washed to the gulches below. II
Il coarser particles Of gold lodge in Il
:. gravel and clay as il did in Californ
il gulch from of the Mosquito range, b
l. the finer particles and the silver whiC
N dissolves are carried back TO the oce;
= and again take part IN mine making
Is As The palaeuzoic rocks lie next to d
e eeZoic, follow up the mountain sides