Graham guardian., 1905-10-20
Deposits in GIiffon-MorsneI District


The copper deposits of the Cliff
ton. Morenci district, Arizona, were
discovered in 1872, but for many
years their development was slow
because only rich ores could be
utilized, as the district was far
from established lines of communi.
cation. Since 1890, however, the
progress of the district has been
rapid. At the present time large
bodies of low grade ore are utilized
and production has reached high
figures. A professional paper (No.
43) recently published by the
United States Geological Survey
will therefore be of interest 10
many. 1t is entitled "The Copper
Deposits of the Clifton Morenci
District, Arizona" and is the work
of Mr., Waldemar LIndgren.
The scope OF Mr. Landgren's in
vestigation is very broad. Besides
discussing the general geology Of
the district, its ore deposits and
their minerals, and the principal
characteristics of these deposits,
he devotes a separate chapter to
the metasomatlc processes repre-
sented in the rock structure of this
district, and describes the many
mines in detail. The illustrations
include 25 Photographic plates
and 10 figures. Among the plates
is a geological map of the Clifton
Morenci district and a geological
and Typographical map OF the
vicinity of Metcalf
In 1902 the total production of
this district rose to 49,5O0,000
pounds of copper; in 1908 it had
attained 53,400,000 pounds, with "a
value of about S7,400, 900. Two
strong companies, the Detroit Cop.
per Company and the Arizona
Copper Company, have contributed
by far the greatest part of the pro-
duction since 1882. Since 1902 a
third, the Shannon Copper Com
pany, has been added. The mines
of the Detroit company are located
at Morenci, those of the Arizona
company at Morenci and Metcalf,
and those of the Shannon com
pany at Metcalf. OF the produc-
tion of 1903 the Arizona company
contributed 20,228,O00 pounds, the
Detroit company 16 55S, ,232
pounds, and the Shannon company
100000 pounds. The total out
put of the district to the end of
1908 is estimated to be about 201,-
900 short tons of copper, having a
value ofapproximately $50, 100000
The ores mined average 3 or 4
per cent of copper. Tho monthly
output of ore in 1902 was about
$4,000 short tons. OF this $4,000
tons we're classed as concentrating
ore and l2,000 as high grade
smelling ore, with six to ten per
cent copper. The Arizona com
pany smelted the lowest grade Of
ore, while the Detroit company
averaged somewhat higher. The
ore of the Shannon company were
in 1902 exclusively oxidized ores,
containing about per cent cop
per. Since then this company has
also begun the mining OF concen-
tratng ore. By far the larger
Of ore consisted of
ore, containing pyrite and
chalcocite. Ofoxidized ores about
$4,000 tons a month were mined
at Metcalf, and a steadily diminish
ing amount from 1900 tons month
at Morencl, making a total ofI
l4,500 tons, or about one.fourth
the total production. The output
of oxidized orc at Metcalf will
for number of years aud
possibly increase The oxidized
ore mined by the Arizona Copper
Company at Metcalf is the lowest
grade utilized in the district, and |
probably contains on an average
less than three per cent.
Mr.. Lindgren believes that the
future of the camps is assured for
many years, since the low grade
ore bodies, which are now the
nainstay of the district, are of
very large extent, and the pro-
luction bids fair to keep up at
east the present rate for some
lime to come. Mr.. Lindgren's
paper is among the Surveys free
and may be obtained |
IN application to the Director OF
he Geol ogical Survey, Washing. |