Hydrothermal Deposits - Metals and Society: An Introduction to Economic Geology - page 92

Box 4.3 The Long History of a Famous Porphyry Deposit,
Chuquicamata, Chile
(a) Google Earth image of the main Chiquicamata open pit and the smaller Exotica deposit
to the south; (b) geological map of the deposit (Ossandon et al. 2001 ).
The Chiquicamata Cu-Mo porphyry mine in the Atacama Desert of north-
ern Chile has been described as the world's greatest mine. With an annual
production of copper close to 600,000 t, it was for many years the greatest
producer of the metal and despite almost a decade of continual production it
still constitutes one of the largest copper resources. It is also a major producer
of Mo.
The discovery in 1899 of “Copper Man”, a mummy trapped in an ancient
mine shaft and dated at about 550 A.D. reminds us that copper has been
mined in the region for many centuries. It is claimed that the conquistador
Pedro de Valdivia obtained copper for horseshoes from the natives when he
passed through in the early sixteenth century.
Mining was limited until the War of the Pacific when Chile annexed large
parts of Peru and Bolivia. 'Red Gold Fever' (La Fiebre del Oro Rojo) then
drew numerous miners to the Chuquicamata region.
At the beginning of the twentieth century only high grade veins containing
10-15% copper were mined and the disseminated ore was ignored. An
attempt in 1899 to process the low-grade ore failed and mining never really
developed because of the lack of water, poor communications, a lack of
capital, and an unstable copper price.
In 1910, Bradley, an American engineer, finally developed a method of
working low-grade oxidised copper ores. He contacted Burrage, a lawyer and
industrialist, who approached the Guggenheim Brothers to finance the