The UK and Toronto-listed group now expects to produce between 52-000–57,000 ounces of gold in 2017 compared to 60,000 ounces previously, though this still represents a rise on 2016 of 4% at the lower end and 14% at the top it said.
Because of the work to deepen the central shaft at Blanket, it has not been able to transport the volume of material necessary for 60,000 ounces of gold without disrupting the mine development plans.
Earnings guidance for 2017 has also been reduced from 34c to between 24 and 31c per share assuming a gold price of $1,275 per ounce, though this too would be 12% higher at the bottom compared to 2016.
Dividends are not likely to be affected by the lower production this year, the miner added.
Expansion of the central shaft is on schedule for completion by the fourth quarter of 2018.
The miner is drilling down to 1,080m to enable mining below 750m and open up more of the reserves at the mine.
When finished, Caledonia expects output of approximately 80,000 ounces per year by 2021 and this estimate was not affected by today’s revision.
Shares eased 2% to 100.5p.