Gold producer Newcrest Mining says its biggest mine is likely to fall short of its production guidance after an earthquake put a halt to operations.

Work at the Cadia gold and copper mine in central west NSW was suspended after a magnitude 4.3 earthquake struck in the early hours of Good Friday.

There were no injuries at the site and a preliminary assessment has shown no major damage to the mine. A detailed assessment is underway, Newcrest said.

The mine is now subject to a prohibition notice from authorities, and extensive cleaning up, testing of critical infrastructure and rehabilitation will be required before it is approved safe to resume operations.

Newcrest said it could not say when the restart will happen, but Cadia is not expected to meet its production guidance for the 2016/17 financial year.

An updated guidance range is expected to be announced once plans for resuming mining operations is finalised.

Cadia accounts for roughly 30 per cent of Newcrest's output and is also the miner's highest margin operation.

Newcrest shares were down $1.02, or 4.1 per cent, at $24.11 at 1315 AEST.

"We expect the market may be concerned around risks to what is clearly a marque asset in Newcrest's portfolio," RBC Capital Markets analyst Paul Hissey said.

He estimated that a shortfall of up to 50,000 ounces in Cadia's gold production could be temporarily filled by the company's other mines, muting the financial impact.