Pit-wall slide halts production at Deep Post

Denver — A pit-wall slide on the south side of the Betze-Post pit has caused Newmont Mining (NEM-N) to halt production at the Deep Post gold mine in northern Nevada.

The pit, which is operated by Barrick Gold (ABX-N), will remain closed for several days while federal and state inspectors complete their investigation.

The Deep Post, which sits beneath the Betze-Post pit, was supposed to be protected from open-pit operations by a 150-ft. buttress covering the bottom of the pit nearest to the Deep Post workings.

The buttress, consisting of chain-link fencing covered by cemented backfill and reinforced with steel cabling, was to allow mining from Deep Post right up to the surface of the pit.

“At this point, we don’t know what role the buttress played in the slide,” says Douglas Hock, a Newmont spokesman.

Newmont and Barrick were monitoring the southern pit-wall for the last several months, since it showed signs of movement.

The decision to evacuate the Deep Post was made early in the morning of Aug. 28. All personnel were safely evacuated and no injuries were reported before the slippage occurred.

However, power was disrupted for a short time and debris from the slide buried the buttress and several pieces of equipment belonging to a contractor.

Debris also covered a secondary portal. The main portals, situated 600 ft. east of the slide, were unaffected.

Newmont has not yet had the opportunity to inspect the damage to the underground workings. The company does not believe that reserves at Deep Post will be affected. The impact the slide will have on production is also not known.

The two companies have been jointly operating the Betze-Post deposit on Nevada’s Carlin Trend since 1992.

Deep Post, where operations began in February, contributes 160,000 oz. gold annually to Newmont’s bottom line.