Porphyry copper deposits are currently the largest source of copper ore. Most of the known porphyrys are concentrated in: western South and North America and Southeast Asia and Oceania - along the Pacific Ring of Fire; the Caribbean; southern central Europe and the area around eastern Turkey; scattered areas in China, the Mideast, Russia, and the CIS states; and eastern Australia. Only a few are identified in Africa, in Namibia and Zambia; none are known in Antarctica. The greatest concentration of the largest copper porphyrys is in northern Chile. Almost all mines exploiting large porphyry deposits produce from open pits.