Seismic ground fall impacts St Barbara production

The Gwalia gold mine. Image: St Barbara.

St Barbara has suffered a setback to its operations at the Gwalia gold mine after a fall of ground event at the Western Australian mine.

The fall, which occurred at the underground mine on September 9, was triggered by a large firing that triggered seismic events, the largest of which measured at 1.9 local magnitude.

No personnel were underground at the time and all at depth work was suspended pending assessment of the seismic information.

The fall of ground was identified upon re-entry to the mine and occurred within the Hoover Decline, approximately 1600 below the surface.

“The geotechnical risk is well understood and closely monitored,” St Barbara stated in an ASX announcement.

“Investigation and rectification work took longer than initially anticipated, as although the longest dimension of the fall of ground was three metres, ultimately a total of 30 metres lateral rehabilitation was required.

“The decline has reopened and mining activity has resumed below this level.”

St Barbara estimates that approximately 8000 ounces slated for production during the first quarter of this financial year will now be delivered in the second quarter.

The company, therefore, maintains a full year production guidance for the 2021 financial year for Gwalia at 175,000–190,000 ounces of gold.

St Barbara will provide further comment on the event and operations in its September quarterly report, scheduled for release on October 21.