Technological innovation in drilling, blasting, loading and transport made it profitable to mine large low-grade porphyry copper deposits.
12.
The deposit is a large porphyry copper-gold-molybdenum deposit, and if developed would be a major producer of those metals.
13.
For a more balanced but still dated account see A . B . Parsons, " The Porphyry Coppers ".
14.
In 1907 he started up the Ray copper mine in Arizona, one of the first large scale porphyry copper operations.
15.
Its activities include the extraction, exploitation and production copper from the porphyry copper deposit located southeast of the city of Arequipa.
16.
Copper is produced from two large open-pit porphyry copper operations in Grant County : the Chino Mine and the Tyrone mine.
17.
Porphyry copper deposits represent an important resource and the dominant source of copper that is mined today to satisfy global demand.
18.
"' Kerr "'- Recognized as a porphyry copper deposit since 1987 ( specifically a modified porphyry deposit with unique characteristics ).
19.
Covellite and other copper sulfides found in the area appear to have formed through postvolcanic epithermal mineralization above deep porphyry copper mineralization.
20.
Porphyry copper ore deposits are formed by concentration of copper within a granite stock during the ascent and crystallisation of a magma.
