Australia's mineral and petroleum exploration sector is facing a major cash crunch as 43 per cent of explorers hold less than $1m after the coronavirus froze the flow of funds into the high risk sector.

The rush of raisings that saw more than $24 billion pumped into Australian corporates this year has not extended to explorers, whose cash inflows slumped by 48 per cent in the first three months of the year to a four-year low.