The San Francisco call. [volume] (San Francisco [Calif.]) 1895-1913, 1896-08-21
Spectators May Traverse With
Speed Six Large
Counties
AND STUDY ALL THE ROCKS
Without Moving More Than a Few
Feet During the Entire Pros.
pecting Journey.

sion concerning the precious metals as
recently has been and still is in prog
ress should attract great attention to
gold mining in California. One ar
gument urged by one party is that
gold is so scarce that it can be co rnered.
Indeed, Mr.. Bryan, the Democratic P opu-
list candidate for the Presidency, asserted
in his Madison Garden speech in New
York that the gold product of the world
could be represented by 22-foot cube,
while the silver product would make only
66foot cube. The official returns of the
State Bureau of Mining show that during
the wear 1895 the Stat of California pro-
duced in gold SIS, 1874, 317 10 as returned to
United States Mint, and the silver product
of California in the same year as returned
according to the same authority amounted
to only $3.50, 7S9 70. These figures show
conclusively the preponderance OF the
gold interest in this State and also indi.
cate the important part that this State is
now playing on the stage of international
finance.
The cube of gold introduced by Mr..
Bryan in his speech has also large inter-
est here, for in 1885 California sent to the
exposition at St. Louis a cube of over four
teen feet, representing the California pro-
duction of gold up to that time.
All parties being agreed upon the in
trinsic value of gold, or, rather, that it
has large intrinsic value, the gold produc-
tion of this State becomes continually a
more engrossing subject of concern. Sill
yer, since the slump in value of that
metal. has cut comparatively small
figure in California production. The
Inyo County prod uction and the San Ber-
naroino mines have history which is too
generally known among mining men and
hnanciers to make repetition necessary
here for common information. "Where
can we successfully mine for god2' is a
daily question at the State Bureau of
Mining. In response to this inquiry H.
s. Durdon, the curator of the museum at
tached to the bureau, has prepared an il
Illustrative object-lesson, which is compre-
hensive, striking and novel.
A large amount of the gold mined in
California has been taken from the mines
along what is known as the "morher
lode" in Mariposa, Tuolumne, Calaveras,
Amador and Ell Dorado counties. Some
years ago Harold w. Fairbanks spent five
months studying up the story of the
geology OF the mother lode" of which
three months were passed in the field and
two months were devoted to the making
of maps showing the course of the
mother lode," the location of mining
claims and the preparation of the speci-
mems which were picked up along the looe,
and also within belt five miles wide, ex-
tending on either side of the lode. The
geological specimens in the ore-bearing
lode and in the country Immediately con-
tiguous were carefully designated and
mum bered by Mr.. Fairbanks, the numbers
80, H.
geological map, which was made part of
the exhibit.
No scheme of greater accuracy Or more
definiteness could seemingly have been
devised to indicate the characteristic rock
of the lode and iii the country adjoining
within the counties named. The lode in
Ell Dorado County was traced through to
the Middle Fork of the American River,
but the in closing rocks were only partially
lode in only five counties was com pletely
presented. 1t occurred to Mr.. burden
that the geological specimens collected by
Mr.. Fairbanks should be exhibited.
A glass case has just been filled with the
specimens and the geological map and the
arrangement is such that inQuirers can
see in study of few hours more than
they. could learn in months Of weary pros
pecting so far as an exhaustive examina-
ton of the rock formations of the coun-
try all along the lode Is concerned.
The specimens are arranged in order
from Mariposa County onward, while d.
rectly above hangs the map showing the
lode in each OF the counties enumerated.
and on the map are the numbers corre-
spending to the numbers of the speci-
mems. Miners study these specimens and
maps for knowledge of these counties. OF
course, they are applicable to only those
localities, but they are of value in that
connection.
Mr.. Fairbanks had in view in making
his reconnaissance to give thorough
knowledge of the occurrence of the ores
and to scientifically explain what he de-
scribed as lone OF the most remarkable
metalliferous deposits in the world" The
descriptions are to be found in the report
of 1890. The specimens which were act
ually taken from the lode and its vicinity
are on exhibition.
These give an approximate idea of the
physical characteristics of the vein. The
mother lode" according to Mr. Fair
banks description, and this description
will be read with interest everywhere,
"may be defined as series of gold -bearin o
veins of definite characteristics and often
of great magnitude, forming a nearly
continuous line over 100 miles long. They
usually occur in a belt of black slate. with
either slate, diorite, diabase. serpentine
or occasionally granite as wall rock,
They are generally distinguished by
peculiar green vein-matter, known as
mariposite, and by the more or less rib
bon-like character of the quartz. As far
as can be learned the term s'mother Iode''
was first applied to the veins washed at
Nashville, twelve miles south of Placer
vile, Ell Dorado County, in the latter part
of 1850 or earlier part of 1851.
The extent of the mother lode has been
discussed and different conclusions have
been reached. There are geologists who
believe that it extends all the way to
Alaska. The region traversed by the
mother lode is characterized by vertical or
steeply inclined rocks, which are either
aruptive dikes or sedimentarv strata.
Each of the four formations, granite.
slate, serpentine and diabase. is char
acterized by a different surface. The
granite. according to Mr.. Fairbanks. is
best illustrated by that body of massive
rock at the southern termination of the
lode and is characterized by rolling sur
face and by light but fertile soil. The
serpentine, unless lying in valley where
it receives the wash from other rocks. is
uniformly distinguished by an almost
barren surface with scarcely any soil. no
grass and only a few stunted trees. It's
rapidity Of erosion is between that of the
orv al lipa and the W rocbs