South Africa will move ahead "decisively" with the exploration of shale gas, the country's minerals minister said in Cape Town on Tuesday.

Minerals Minister Susan Shabangu said that "geology indicates" a potential for 485 trillion cubic feet of shale gas trapped in the formations of South Africa's arid Karoo region.

"We will move ahead decisively, yet responsibly with the exploration of shale gas," Shabangu said, adding that the government would "unleash" the potential of shale gas to provide "cost-competitive energy security" and create jobs.

Shabangu, speaking at the opening of a major mining conference in the city, said legislation governing the exploration would come soon.

"We have published the technical regulations for the development of shale gas for public comments and the final regulations will be released shortly."

Environmentalists have vociferously opposed the drilling for shale gas, known as fracking, in the Karoo region, saying it has the potential to poison the area's underground water supply.

The process involves digging wells up to four kilometres (2.5 miles) deep, before pumping in a cocktail or water and chemicals to crack the shale rock and release the gas.

President Jacob Zuma said last year that shale gas has the potential to transform South Africa's economy by, among others, reducing the price of its energy.

Shabangu said South Africa was also nurturing the development of its offshore oil and gas prospects and the country "welcomed" a number of multinationals that had expressed interest in the development of "this resource".