MINE PRODUCTION OF GOLD AND SILVER, BY STATES.
ALASKA.
The
total production of gold in Alaska from the earliest mining, in 1880,
to the end of 1920 is estimated at $320,030,553, and that of silver at
9,972,562 fine ounces.
Gold.—The
yield from siliceous ores increased from $4,392,237 in 1919 to
$4,473,687 in 1920; that from copper ores decreased from $63,795 to
$18,873; the placer output was $3,873,000, against $4,-970,000.
Twenty-two dredges produced $1,129,932 of the placer gold, which was
$230,068 less than the dredge output in 1919.
The
3,413,736 tons of siliceous ores treated in 1920 yielded an average of
$1.39 in gold and silver a ton, and the 765,025 tons of copper ore
contained $1 in gold and silver a ton and had a copper content of 4.6
per cent.
About
53 per cent of the total output of gold in Alaska came from gold lode
mines in 1920, against 47 per cent in 1919, 37 per cent in 1918, 31 per
cent in 1917, and 29 per cent in 1912. The 570 placers operated in 1920
yielded 3,440,000 cubic yards of auriferous gravel, of which the
dredges handled 1,634,000 cubic yards and made an average recovery of
69 cents a cubic yard in 1920, against 77 cents in 1919 and 57 cents in
1918. The estimated total recovery of gold by dredging for the period
1903-1920 is $21,524,826.
No important new placer-bearing areas were reported in 1920.
Silver.—The
mine production of silver in Alaska in 1920 was 953,546 fine ounces,
against 629,708 ounces in 1919. The copper mines produced 682,033
ounces, an increase of 193,999 ounces; the siliceous ores 246,292
ounces, against 108,691 ounces in 1919; and the placers 25,221 ounces,
against 32,983 ounces.
