One of the World’s Largest Copper Producers

Arizona is at the heart of America’s mining industry and is home to some of the world’s largest copper projects, owned by major mining companies including BHP, Rio Tinto, Freeport McMoRan and Hudbay Minerals.

Arizona accounts for 66% of the United States copper production. If Arizona were a country, it would be the world's 7th largest copper producer, with Chile, China and Peru holding the top three positions.

Economic Benefits of Mining in Arizona 

In 2018 the mining industry contributed approximately US$6.5 billion to Arizona’s economy. An estimated 38,000 jobs are connected to the mining industry with the sector continuing to be a leading industry in several Counties throughout the State.

Arizona Geology and Porphyry Copper Deposits

Arizona hosts several types of copper deposits including porphyry copper, skarn and volcanogenic massive sulfides.

The majority of the copper mined in Arizona is sources from porphyry copper deposits associated with intrusive rocks similar to granites. The term "porphyry" describes the typical texture of these rocks, in which individual mineral grains about 2mm to 125mm in size, are surrounded by smaller grains that are barely visible to the naked eye. These deposits are formed from saline, metal-bearing fluids expelled from cooling magma. Interaction of these fluids with groundwater yields a chemically reactive solution that modifies the mineralogy of the rocks adjacent to the intrusion.

The intrusive activity responsible for Arizona's porphyry copper deposits occurred approximately 65 million years ago in the earth's crust deep below the surface. The rich metal deposits were subsequently exposed millions of years later by faulting and erosion. Weathering processes, which accompany uplift and erosion, sometimes further concentrated the copper.

Sources:
https://www.azmining.com/economic-impact/
https://azgs.arizona.edu/minerals/mineral-rights
https://www.statista.com/statistics/264626/copper-production-by- country/#:~:text=Chile%2C%20the%20world's%20leading%20copper,producer%20from%20mines%20is%20China.