Ancient volcanoes provide clues to find vital metals

A new study published in the journal Earth and Planetary Science Letters by Dr Yanbo Cheng, Associate Professor Carl Spandler, and colleagues from the Economic Geology Research Centre, James Cook University, has examined volcanic rocks and granites associated with tin, tungsten and molybdenum ores from the Herberton region of north Queensland.

Dr Cheng said the metals are crucial for sustaining modern societies.

“Tin, tungsten and molybdenum are needed for a variety of industrial and high technology applications, such as high temperature electronics, superconductors and high performance batteries. But they are becoming harder to find,” he said.

Dr Cheng said future discoveries will rely on new technology and methods to help find ore bodies buried at great depths.

“We discovered that certain kinds of volcanic rocks formed at the Earth’s surface at the same time as the deeply buried metal ores, some 300 million years ago. We demonstrated that these rocks have a distinctive chemical signature that can be traced to the deep ore forming processes. This means they could be used as an indicator of underlying ore bodies far beneath.”

Dr Spandler said that volcanic rocks of this type cover a large proportion of continental landmasses, so the results of the study can help guide mineral explorers to locate new deeply buried tin-tungsten-molybdenum ore bodies.

The study also linked ore formation processes to large-scale plate tectonic changes that affected eastern Australia at the time.

“We can use this information to focus mineral exploration efforts on prospective geological environments undergoing similar tectonic transitions today, or in the geologically recent past,” said Dr Spandler.