Copper stream deliveries from Mount Milligan were approximately 2.5 million pounds during the three months ended December 31, 2020, compared to approximately 4.4 million pounds during the three months ended December 31, 2019. Decreased deliveries resulted from differences in the timing of shipments and settlements during the periods.
On January 14, 2021, Centerra reported that Mount Milligan produced approximately 161,900 ounces of gold during calendar 2020, above previously issued gold production guidance of between 140,000 and 160,000 ounces. Centerra also reported that copper production for calendar year 2020 was 82.8 million pounds, in line with previously issued copper production guidance of between 80 and 90 million pounds.
Pueblo Viejo
Gold stream deliveries from Pueblo Viejo were approximately 10,500 ounces for the three months ended December 31, 2020, compared to approximately 13,200 ounces for the three months ended December 31, 2019. The decrease in deliveries resulted from lower grade and recovery rates. On January 14, 2021, Barrick reported that its 60% share of Pueblo Viejo gold production during calendar year 2020 was 542,000 ounces, in line with previously issued guidance of between 530,000 and 580,000 ounces.
Silver stream deliveries were approximately 418,200 ounces for the three months ended December 31, 2020, compared to approximately 417,800 ounces for the three months ended December 31, 2019.
Barrick reported continued progress at Pueblo Viejo during the quarter to expand the process plant and tailings storage facilities. Barrick estimates that the expansion project could significantly increase throughput and allow the mine to maintain average annual gold production of approximately 800,000 ounces after calendar 2022 (on a 100% basis), and that the increase in tailings storage capacity has the potential to convert approximately 11 million ounces of mineralized material to reserves (on a 100% basis).
As reported by Barrick, the Environmental Impact Assessment for the process plant expansion has been approved and an amended environmental license has been issued, and progress continued with engineering, procurement of long lead equipment packages, earthworks and tendering of contracts for construction activities. Barrick also reported that studies and permitting discussions to support additional tailings capacity continued to progress.
Wassa
Gold stream deliveries from Wassa were approximately 4,700 ounces for the three months ended December 31, 2020, compared to approximately 4,900 ounces for the three months ended December 31, 2019.
On January 20, 2021, Golden Star reported full calendar year 2020 gold production from Wassa of 168,000 ounces, within the revised guidance range of 165,000 to 170,000 ounces, and a 7% increase over 2019 production. Golden Star also provided full calendar year 2021 gold production guidance of 165,000 to 175,000 ounces.
Also according to Golden Star, work on a preliminary economic assessment of the expansion of the Wassa mine into the southern extension of the Wassa ore body is nearing completion, with release of the study results in conjunction with an updated reserve and resource estimate expected from Golden Star in February 2021.
Royalty Interests
Cortez
Production attributable to our royalty interest at Cortez was approximately 57,600 ounces of gold for the three months ended December 31, 2020, compared to approximately 28,000 ounces of gold for the three months ended December 31, 2019.
Barrick expects production in calendar year 2021 to increase from calendar year 2020 primarily due to higher contribution from the Crossroads deposit, which is expected to ramp up through calendar year 2023 and offset declining production from the other royalty regions.