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MINERAL RESOURCES.
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were
recovered, which, however, did not add to the output of precious
metals, although the ores, which are mixed sulphides, arsenides, and
antimonides, sometimes carry as much as $5 to the ton in gold,
particularly in the pyrite. Since the American occupation production
of gold by the Igorots has continued. In 1907, 2 triple-discharge Hendy
stamp mills, with cyanide equipment, on the claims of the Benguet
Consolidated Mining Company, near Baguio, began production from
siliceous ores. In the Camarines, particularly at Paracale and
Mambulao, European interests at one time did extensive underground work
and erected modern mills. Their work was interrupted by the native
insurrection of 1896 and has only been resumed in a small way by
American miners in the last few years. The ores are partly sulphides
and partly oxidized siliceous ores. There has been no production from
the mines in the last twelve years. Antedating the Spanish conquest of
the islands, the natives of the Camarines worked the placers of these
districts and have ever since made an annual production, which was of
considerable importance in the early years. This led to investigations
by representatives of American and New Zealand capital, and in 1907 a
New Zealand dredge was installed, which has since been working with
most promising results, contributing largely to the output for 1907. In
the northern part of Masbate, at Aroroy, are many old abandoned gold
mines of the Spanish regime, or of earlier times, and these have been
actively prospected and partly worked by American miners. The ores are
siliceous and oxidized to water level, where they give way to
gold-bearing pyrite. Several stamp mills were erected by Americans, and
one of them was run for several months in treating an old dump carrying
good values in free gold. Examination of the streams of this district
led to the installation of 2 modern American dredges, one of which has
since shut down. The total production to date from Masbate in the last
ten years has been small.
Considerable
gold is mined by natives in Mindanao in placer workings each year, but
reliable estimates of the output are not available.
Silver
ores occur rarely in the Philippines, the one notable occurrence
having been found in northern Benguet, near the Lepanto line. This is
in part native silver, but the deposit has not been developed. Lead
ores, carrying silver, occur in the islands of Cebu and Marinduque, but
they have not been developed up to the present time.
NUMBER OF MINES, ORE PRODUCTION, AND AVERAGE VALUES.
The
following table indicates the number of producing mines in 1907,
divided into placer mines and deep mines. In the former mines values,
generally in gold, are extracted from gravels or sands; the "deep
mines" work deposits in solid rock which have not been disintegrated
and sorted by erosion. The total number of mines is of course much
larger than the figures given, because many properties for various
reasons are idle or are being developed without having yet attained a
producing stage.
It
is perhaps a little difficult, especially in the case of placers, to
define what constitutes a mine. In some places a fairly large
aggregate output is obtained, usually through traders and
storekeepers, from transient or intermittent work of wandering miners
which can not be credited to separate properties.
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