Australia's biggest miners will spend $US213 billion ($210 billion) in capital on new and existing projects over the next seven years, more than half of it in this country, despite a new focus on costs.
Commodity prices have fallen and investment levels have peaked but the third leg of the resources boom - the boom in volumes - has yet to run its course, analysts say.
In a note published on Monday, the Commonwealth Bank's Andrew Hines estimates the combined capital expenditure of BHP Billiton, Rio Tinto and Fortescue Metals will top $US107 billion between 2013-20 in Australia alone.
Total capital expenditure by the big three was just $US97 billion in the first decade of the century; it will reach $US289 billion this decade, CBA expects.
The forecasts are dominated by expected investment in the Pilbara, with Rio lifting its production above 410 million tonnes per annum (mtpa), BHP investing to lift production above 240 mtpa, and Fortescue lifting capacity to 155 mtpa over the next two years.
Otherwise CBA assumes the only new projects to be approved will be Rio's Hail Creek and Mount Pleasant coal projects. BHP and Rio's other planned Australian coal projects will be shelved, CBA assumes. BHP's massive Olympic Dam expansion in South Australia, and its Scarborough gas development off WA, also are shelved.
The CBA forecasts do not count approved and expected investment in booming sectors like oil and gas, or investment by other foreign, private or junior mining companies.
The forecast comes as official figures released Monday showed an 18 per cent increase in petroleum expenditure in the December quarter, although there was a sharp 7 per cent drop in spending on mineral exploration, particularly gold and coal.
HSBC Australia chief economist Paul Bloxham said "the mining story is not over yet and the death of the mining boom has been greatly exaggerated".
He said last week's capital expenditure figures, particularly the first forward estimates for 2013-14, showed mining investment should rise further yet and "plateau rather than peak" - particularly with seven massive LNG projects worth $US190 billion under construction.
"The economy gets more support from mining investment yet," he said.
"Which gives more time for monetary policy to support the other parts of the economy and for the RBA to get a rebalancing."
New chief executives at BHP and Rio, Andrew Harding and Sam Walsh, appointed in the last two months, flag a renewed emphasis on capital discipline after a spate of unsuccessful acquisitions and shelved mega-projects.
Shares in both companies fell on Monday with BHP Billiton down 3.5 per cent to $35.57 after it went ex-dividend, and Rio down 3.7 per cent to $63.65 following weak Chinese manufacturing data.
At a presentation in Sydney lodged with the stock exchange on Monday, Rio Tinto's chief economist Vivek Tulpule predicted a stronger first half in the Chinese economy, followed by a moderation.
Iron ore supply was vulnerable to downside shocks, Mr Tulpule said, and his presentation highlighted an expected fall in iron ore prices from their current levels above $US150 a tonne back to $US100 a tonne by the end of 2014.
Rio remained confident in the long-term outlook for iron ore with finished steel per capita intensities in the economies of south-east Asia, Brazil, India and Africa unlikely to peak before 2040.