The San Francisco call. [volume] (San Francisco [Calif.]) 1895-1913, 1897-12-19

SLfeICneS IOr 10 miles or so
p along the western slope of the
Sierra Nevada Mountains
from Plumas to Mariposa
County in two parallel belts.
For this distance it is an almost con-
tinuous stretch Of series and punches
OF veins and ore masses varying from
a few inches to 900 feet in width.
These veins, resulting from eruptive
assures in the earth's crust, extend to
unknown depths.
The very few deep shafts yet sunk,
the deepest being 1900 feet in vertical
depth, in the kennedy mine, or nearly
half a mile, show no narrowing in the
veins or change in the average value
of the ore.
These deep" shafts and tunnels
along these 125 miles of belt are com
paratively few.
The immense region of Northern
California, comprising many thousands
of square miles, is also scanned with
collaborating quartz. Prospecting is
hardly begun there. South of the
mother lode, through MADEIRA, Fresno
and Kern counties, the Sierra Nevadas
likewise display a wealth of quartz
veins which remain practically un-
touched and unexplored.
During the past year the Randsburg,
Panimint and other districts in the
south have indicated the great mining
possibilities of the desert regions.
They are found to be veined with gold
bearing ore. San Diego County car
ries the surface indications of wealth
to the Mexican line.
a cube 300 feet square, representing
approximately the highest develop
ment Of quartz mining in California,
may. perhaps fairly be taken to repre-
sent one-tenth of the quartz that has
been mined in this State to date. If
so the total yet to be mined in the
mines would be ten such cubes.
No practical miner may even hazard
a guess. at the volume of the pay ore
in the nultitudinous veins that seam
the foundations of the State along this
broad gold belt OF over a thousand
miles. If one conceives those ten cubes
as compared with the infinitely greater
volume OF gold ore yet in the earth he
may form a vague conception of the
force of the statements that the sur
face of the State has hardly been
scratched" and that quartz mining in
California is in its very infancy"
Drift mining in California has an I'M
limited future before it. Hundreds Of
millions Of dollars will be taken from
the ancient placer" auriferous
gravels of the warehouses; of a for
rner age, now buried under lava and
other deposits.
It is pretty generally understood
that the western slopes of a large
stretch Of the Sierra Nevada were
once drained by system of water
courses different from that Of the
present day Their beds and bars were
enriched with gold by the process
common to the functions of all placers.
AT later period vast overf1ows of lava
and other like courses changed the
topography. buried these ancient chan
nels and another system of waterways
was developed. With the new system
began the formation of the recent"
surface pIacers which to date have
yielded the great bulk of CALIFORNIA;
gold product.
The buried beds Of these ancient
streams are now found in the middle
of hills and in all manner Of odd situa-
tons In some cases they may be
worked by simply washing down
deep aLuviaI deposits everything them
by the hydraulIc process. Generally,
however, they are worked by tunnel
Ing into the bottom of the old channel
and drifting along its course and min
ing out the rich gravel near the bed
rock.
The extent of these ancient water
ways can only be guessed at. To date
their exploration has been exceedingly
small, but nearly all of them dis
covered have proved to be enormously
rich.
Engineer John Hays Hammond, in
his contribution to THE Auriferous
Gravels of California" an annual re-
port Of the State Mineralogist for 1889,
says: q
The aggregate length Of NJ
the ancient water channels ~
of the State has been esti- s: