A fresh discovery of copper in an area once labelled the richest square mile on Earth because of its abundant metal deposits has raised the possibility of a revival for one of the UK’s most historic industries.
During exploration for lithium in hot underground springs in Cornwall, engineers came instead upon high-grade copper in a previously unmined area.
Further drilling will take place to confirm the extent of the discovery in the parish of Gwennap, near Redruth, but there is cautious optimism that the discovery could kickstart something of a comeback for the industry.
“It’s a very exciting new discovery,” said Richard Williams, the chief executive of Strongbow Exploration, which owns the mineral rights at the site United Downs. “It tells us there are areas of mineralisation that are relatively close to the surface and are potentially mineable. The plan is to get back in there and do some additional drilling to find out how big the zone is.”
The copper was 100 metres down but the company believes the zone could extend close to the surface. Surrounding mines were worked to a depth of 500 metres below the surface. Williams said: “The hope is that this zone continues to that depth and continues laterally east and west.”
He said the global average grade of mined copper is about 0.5%. “We’ve found in this zone the average is 8% copper – 16 times the average grade. Those types of grade are pretty rare,” he added.
Cornwall has a long and proud mining history stretching back to the early bronze age. Reserves of copper, tin, zinc, silver and arsenic have all been exploited for many centuries.
Gwennap was the richest copper producing region in Cornwall (and the world) in the 18th and early 19th centuries, earning it the title of “the richest square mile on Earth”.
As well as making fortunes for mine owners, the industry had a profound effect on the cultural life and social history of the far south-west of Britain.
It gave the world the Cornish pasty – originally a wholesome and practical lunch for miners – and was a backdrop for Winston Graham’s Poldark novels, which were turned into television hits in the 1970s and again more recently.
In the face of competition from abroad and falling demand, mining declined in Cornwall and the county’s last surviving tin mine, South Crofty, shut down in 1998.
But in July 2016 Strongbow Exploration took on South Crofty along with additional mineral rights covering an area of approximately 15,000 hectares (37,065 acres) scattered throughout Cornwall, including the United Downs project.
Strongbow entered into an agreement with a company called Cornish Lithium in January 2017. Cornish Lithium was given the right to explore Strongbow’s mineral rights for lithium in underground salt water, while Strongbow retained the right to any discoveries in hard rock that it came upon.
The work at South Crofty continues. Strongbow recently applied for a permit to drill at the mine. Owen Mihalop, the company’s chief operating officer, said: “The intention is to demonstrate that there is potential to discover a lot more, in particular tin mineralisation at South Crofty. The Covid-19 crisis has delayed that.”
He added: “I think in general people in Cornwall would like to see a resurgence in the industry. The feedback we have received around South Crofty is that people would like to see that back in production. This is a historical mining area. On the whole I think people are positive about the jobs and economic benefits mining can bring.”
A spokesperson for Cornish Lithium said: “Cornish Lithium continues to enjoy a strong relationship with Strongbow Exploration and is excited about the opportunities that this discovery highlights for the mining industry in Cornwall.
“Separately, Cornish Lithium is equally encouraged by the results from our exploration drilling programme for lithium in geothermal waters at this site and are continuing to evaluate the opportunity to extract lithium in this area and elsewhere in Cornwall.”
