How copper forms around volcanoes »

A team of scientists from The Australian National University (ANU) and University of Bristol have discovered how copper ore forms around volcanoes. The findings contradict previous theories of how copper forms, and could lead to changes in exploration for copper, which has limited reserves but is crucial for electricity transmission. Lead researcher Dr John Mavrogenes, from the ANU Research School of Earth Sciences, said the research examined what causes the large copper deposits known as porphyries that form around volcanoes. "We found that these copper deposits need rocks containing both copper and sulphur," he said. "If you look at the volcanic rocks that typically surround these deposits, they are quite rich in copper but very low in sulphur. "But the much hotter rocks below them have a lot of sulphur. That sulphur is percolating up and kneading these rocks and causing the porphyries to form." Dr Mavrogenes said that this discovery contradicts the existing theory that the copper deposits were caused by water that comes from magma.