Mt Gibson Iron is investigating a rock fall in the main pit of the Koolan Island iron ore mine in Kimberley region of Western Australia.
The rock fall occurred in a localised section of the western end footwall and was constrained by protective meshing.
It did not injure any workers or damage any equipment at the site.
The seawall side of the main pit was not impacted by the rock fall and mining in the rest of the Koolan Island main pit continues as normal.
In the impacted area, however, mining has been delayed from its scheduled completion this month and will be recommenced at the end of March 2021.
Mt Gibson is assessing remedial measures to safely resume mining at this time as well as any adjustments it needs to make to the current mine plan.
The company confirmed that its 2020/21 financial year ore sales guidance of 2.8 to 3.3 million wet metric tonnes remains unchanged despite the accident.
Last quarter, Mt Gibson sold 1.4 million wet metric tonnes, 700,000 of which was from the Koolan Island operation with the remaining contributed by its Mid-West operations.
The company mined 5.2 million wet metric tonnes of ore and waste at Koolan Island during the September period, which was a 35 per cent increase compared with the prior quarter.
Mt Gibson plans to complete elevated stripping at Koolan Island for the next 12 to 18 months, which is anticipated to lower sales during this period.