The indicator., 1897-04-24
MINING DEPARTMENT
DvICE OF A NEW KIND FOR PROSECUTORS.
Thomas Smith, in Lecture Before the Denver Miners
Bureau, Attacks the Old Theories of Geo.
logical Formation


Of the biologists and others who have
formulated theories concerning the
formation of blanket veins. His ad-
dress is given below:
prospecting or searching for metal
liferous ores is II business of itself,
separate and distinct from mining
proper. and should never be undcrtak-
en- without first learning all that is
known of the means and conditions of
ore deposition. As the greater number
or the pr0Spcctors now engaged III
hunting for the mineral wealth of this
and other countries have not had the
opportunity 10 study the subject it Is
not surprising thar so many failures
are made. When we take into consid-
GRAFTON the fact that our acknowledged
authorities on geology are themselves
entirely i'll the dark on the subject, 1t
is surprising that so much success has
been attained.
, IN prospecting. the archnen or gran
Ito and the crupiive rocks are of most
Interest. the sedimenlaries of what
ever age being only the recipients of
any ores which may be found in them.
To explain the manner and causes of
ore deposition, shall have to attack
some of the pet theories of the ac-
knowlcdgcd authorities on geology. II
great many of which are stated as
facts.
In the first place metalliferous ores
come from he Interior of the earth
and are elected by dry volcanic heat,
and not by aqueous igncous solutions.
When the earth first commenced to
nool all the water was far above lis
surface in the. form of steam. The
first rocks formed were the lower
crystalline, archaen granite. which
were the lightest fluids in specific gray
ity of the molten mass; ns it solidiiied
cracks were formed. through which
volumes of the molten material poured
which cooled and solidilied on the sur
face of the first crust. This continued
happening for n long time until the
carth's crust became so thick that 1t
would not pull apart by its own con-
traction
''When this surface cooled sufficient
ly the water. which does not belong.
nor cannot stay below the surface of
The earth. except in cavities. descended
In the form of rain and formed the up
per stratum. As the surface continued
TO cool its contraction caused immense
pressure ON the imprisoned fluids until
the weakest part gave way-not in Il
gentle. quiet manner. occupying a long
period of time, but in n sudden paroX-
ysmal manner similar to II boiler eX-
plosion, the effect being to lpheave Il
long line of crust on its edge, and to
make two or three fractures paralleling
one another and some distance apart.
through which the imprisoned fluids
discharged. until the pressure was re-
lieved. Water and steam generation
could have had nothing TO do with 1t
until the vent was made. rs Ii is alb
solutely impossible to make a fluid of II
lighter specific gravity stay below one
pf heavier. 50 the water must have
been above the earth's crust.
"rhese upheavnls have taken place
at different periods and places, and in
some places II number of times. all over
The known surface of the world. and
our minerals have been elected from
these lines of fracture. with the crup-
;ive rocks. When | first studied geolo-
;.y with n view TO utilizing 1t in pros
pecting. | read that the carth's crust
lad been crumpled. folded and faulted
by the contraction of the interior. and
that erIptivc rock pOrphyryl had been
inirudcd or forced between the bed
ding planes of sedimentary rocks, the
same as 1t is taught to-day. 1t was
pretty hard to swallow. like Jonah and
the whale, but. believing that the au-
,thors had evidence which would prove
the facts and having no contrary evi-
dence. | accepted 1t and cndeavored to
utilize the knowledge in my practice.
My experience from that time to the
present in actual field work is that both
al.
sdence proves that the upheaval of the
granite has not been gradual by means
of crImpling. folding and fnllltng. but
violent and extending over
long lines and invariably accompanied
by II large outflow of eruptive rock.
and find also that the laccolite or in
trusiyc theory is disprovcd by the fact
that where an intrusive sheet tso-
called is examined. the evidence of
heat is very marked on the upper sur
face of the sedimeniary rock on which
II rests. but is not visible in the rock
above. proving that the upper sedimen-
ffry rock was not deposited until the
igncous rock had cooled. As most of
the scdimeniary rocks of which our
geological tcNt hooks mainly treat have
hccn deposited through and from water
in II similar manner to the deposition
of snow and water through air. let us
take n few simple Illustrations from
snow.
"SuppoSc after Il storm had ceased
we were 10 find IL gate or section of
fence had vanished and was hidden
by the snow and. in digging it out.
found that ii wus lying half way down
between the surface and the ground.
as much snow above us below. which
would be the most reasonable theory?
That it was blown down when the
storm WAS only half over. and covered
by that which fell afterwards, or. as
orr geological friends would explain
it. that IL had waited till all the snow
had fallen and then intruded itself be
tween the upper and lower layers?
again. if we noticed that layer of
SNOW one foot in depth was lying on
top of house and that layer of the
same thickness were lying on the
ground alongside. would 1t he ncces-
sary to explain it to state That the
earth and house top were on the same
'evcl when the snow quit falling. but
that 1t had fnulted and the earth
had slipped down between that time
and the time of our observation?
II would pay no attention to these
theories. considering them unworthy Of
notice. II they had not been used so
to explain the manner of
nrc deposition and the geology of our
different camps.
when we read that it is necessary
for thermal springs. solfataric action
and intrusive porphyry TO be present
in Il camp before ii can he an ore pro-
Ilucer. and that this nonsense is be-
lieved in. indOrsed and acted on by the
mining engineers. biologists and So
called experts, who are sent down by
to examine our properties.
we can understand what are the
causes which retard the development
,f so many of our camps.
prospecting and ore deposition are
simple matters II we