By Samantha James

RESEARCHERS in the UK have discovered a new way to find large copper deposits by identifying chemical markers in porphyry rock.

A study co-authored by University of Exeter geologist Dr Ben Williamson detailed a new chemical exploration tool that could be used to find porphyry-type copper deposits.

These low quality but high quantity deposits are the most common copper deposits in the world, delivering about three quarters of global copper.

Dr Williamson said the new technique would be the least expensive method of retesting core samples for copper and reassessing explored land.

“We’ve compared the composition of that mineral between magmatic rocks that do form these deposits and those that don’t, and we’ve found there’s a chemical marker, a distinguishing feature that we can use to differentiate magmatic rocks,” he said.

“The least expensive way of going forward for some companies is to re-assess grounds that they already own and have looked at in certain ways.

“If they can apply some old data sets, or new data sets using this method, they may be able to come up with something relatively cheaply.”

The new technique has so far only been tested in South America, but would be applicable in any areas hosting known porphyry copper deposits.

About 11 per cent of copper mined in Australia is from porphyry-type deposits in the eastern states, while 47 per cent is found in iron-oxide copper-gold (IOCG) deposits.

Dr Williamson said the research might also have implications for finding more IOCG deposits.

His research has been touted as having the potential to uncover new mines, and help exploration companies learn more about existing deposits.