Expenditure exceeded A$400 million for the first time since the March 2015 quarter, according to the latest BDO Explorers Quarterly Cash Update.

It was up by 7% over the September quarter to $422 million, with median exploration expenditure increasing by $30,000 to $240,000, the highest in four years.

There were 88 companies that spent between $500,000 and $1 million on exploration, out of the 703 companies that lodged Appendix 5B reports.

Financing inflows increased by $668 million to $2.05 billion and net investing cashflows more than doubled to $524 million quarter-on-quarter.

There were 222 companies that reported net financing cashflows of over $1 million, exceeding the average for the past two years by 71.

BDO said the results were all the more impressive when taking into account a seasonal slowdown in raisings and exploration during the December quarter.

"Despite a projected 22% decrease in cash outflows for the March 2018 quarter, to $2.13 billion, we expect 2018 to be a big year for explorers," BDO National Resources partner Adam Myers said.

"With automation and big data becoming a reality for the mining industry, we anticipate substantial productivity gains for the sector as a whole."

There were 12 initial public offerings during the quarter that raised a combined $69.8 million.

"With 42 companies raising over $10 million each in the quarter it is clear that there is plenty of life in the sector now," Myers said. 

"While much of the focus has quite rightly been on battery minerals, such as lithium, cobalt and graphite, the funds being raised are across the board with oil and gas, gold and iron representing three of the top four commodities by the amount raised."

Four oil and gas explorers raised a combined $272 million, nine gold explorers raised a combined $229 million, and eight lithium explorers raised a combined $206 million.