The San Francisco call. [volume] (San Francisco [Calif.]) 1895-1913, 1908-04-19
RICH TIN DEPOSITS
FOUND ON. COAST
Search for Metals Near Spokane
Reveals Rocks Full of
Cassiterite

WASHINGTON April 1S.-The dis
,covery of tin ore at Silver Hill south
east OF Spokane, Wash, has attracted
considerable attention. Search for
metalliferous deposits and for coal had
been carried on at this place for sew
eral years and prospects of silver bear
ing galena had been noted. The tin
bearing mineral cassterite was identi-
fed as such by Richard Marsh OF
Spokane in the summer of 1905, but
prospecting for tin was not begun until
March, 1907. The first authentic ac-
count of this discovery published out
side of the local newspapers was pre-
and appeared in the Mining and Scien-
tifc Press of June /, 1907. by which
time several carloads of selected ore
had been mined. piled and dumped.
The discovery derived additional in
terest from the fact that no tin ore
had previously been reported from
washington and Arthur j. Collier, one
OF the biologists of the United States
geological survey, was detailed to visit
the locality and examine the conditions.
Collier spent several days early in the
season in going over the prospects and
again visited the region In October to
note the developments made during the
summer. The information gained as
the result of these limited investiga-
lions is embodied in paper just pub
lished by the survey as an advance
chapter from bulletin No. $40, which
forms part l of Contributions to
Economic Geology 1907"
The region about Spokane is rich in
natural resources. The city itself. the
most important of eastern Washing
ton is about 1s miles from the Idaho
state line and 80 miles south of the
Canadian boundary on the lines of the
So Mort In md
Union Pacific railroad systems, and is
the center for extensive agricultural,
numbering and mining interests Vast
expanses of rich wheat lands in the
Palouse and Big Bend countries lie to
the south and west, great forests of
valuable timber are within 100 miles
to the east and the mines of the Couer
d'Alene district, the chief producers of
lead silver ore are within 100 miles to
the southeast Spokane river has a
fall of several hundred feet and fui-
nishes the surrounding country with
water power Several interurban rail-
roads radiating from Spokane are
operated with power from the falls and
on the line of one Of these railroads,
within half an hours ride from the CEN
ter of the city, are the tin deposits.
The location is therefore an ideal one
for mining, milling and shipping ore,
provided it is found in sufficient guam
titles. the only element lacking being
coal, for deposits of this fuel suitable
for smelling tin ores are not known
within $50 miles.
The geology of the Spokane region
has not been studied in detail but the
relations of the rocks in the vicinity
are known in a general way, and a
brief statement of these relations is
given by Collier. The rocks which
seem to be the older in the region COM
prise complex mass of gneisses and
schists. with many igneous intrusions
( of various kinds. These rocks form
/ the mountains southeast of Spokane
and contain the tin deposits.
The eassiterite found at Silver Hill
is nearly black and is without definite
/ crystal outlines 1t is distributed
through a nearly white fine grained
/ rock. characterized by slight tinges
of pink in grains ranging in size
! from that of pin head to several
| inches in diameter. Tin ore of
| this type has been found at four
localities within the area described by
Collier, who discusses also the local
! geology, the characteristics of the ore
| and the developments and form of ore
bodies. In conclusion Collier states
that the developments at Silver Hill
indicate that the tinsore is to be found
in detached masses whose relations to
each other can not yet be determined
The economic value of the deposit will
depend to considerable, extent on the
| amount of excavation necessary to To-
Ecate other ore bodies. This can be
determined only by exploration in
volving further outlay of capital and
possibly requiring several years time
but the discoveries already made are OF
i sufficient value to warrant such investi.
cations. Copies of Golfers paper car
r. 70
I ton d c..