When a tenacious Melbourne prospector kicked a dark, heavy rock while camping in harsh country in Queensland’s north west, little did he know he had stumbled upon one of the world’s richest deposits of copper, silver and zinc; Mount Isa.
This month marks 100 years since John Campbell Miles made the important mineral discovery, setting in motion a chain of events that led to the birth of Mount Isa.
After observing the mineralised rocky outcrops, Miles collected samples using a horse-shoeing hammer and lodged them with the government assayer at Cloncurry on 23 February, the date now honoured as Mount Isa day.
Over two months, Miles pegged out the ‘Racecourse’ lease in the area surrounding the outcrops. He named the larger outcrop ‘Mount Isa’ which is understood to be inspired by the Western Australian gold mining town of Mount Isa.
Due to its remote location, it was not until the Government Geologist E.C. Saint Smith visited the field in September 1923 and returned with high praise that more prospectors made their way to Mount Isa.
Miles established Mount Isa Mines Ltd on 19 January 1924 – Australia’s most distant mine from a coalfield or seaport.
Miles gradually sold off his shares in the company to sustain his prospecting endeavours in Lawn Hill – about 300km north west of Mount Isa.
By 1955 – some 22 years after Miles had sold the last of his shares – Mount Isa Mines Ltd had grown to become the largest mining company in Australia and the nation’s largest single creator of export income.
Miles died in Melbourne on 4 December 1965 aged 82. In 1968 his ashes were brought back to Mount Isa and buried under the clock tower which now stands in the centre of the street named after him.
Resources Minister Scott Stewart said going hand-in-glove with Mount Isa’s growth has been the evolution of copper; from an important building material to playing a key role in the world’s renewable energy transition.
“As the global demand for renewable energy continues to increase, the role of other lesser-known critical minerals in the region like vanadium, cobalt and rare earth elements will continue to grow – providing future jobs and continued growth for the North West, and the whole of Queensland.”