The Cerro Moro low sulfidation, silver-gold deposit is located within the Deseado Massif approximately 70 km southwest of the coastal port city of Puerto Deseado in the Santa Cruz province of Argentina. Cerro Moro contains a number of high-grade epithermal gold and silver deposits, some of which will be mined via open pit and some via underground mining methods. The plant has the capacity to process 1,000 tpd and consists of a crushing, grinding and flotation circuit with a counter current decantation and a Merrill Crowe circuit included.
The Proven and Probable Reserve estimate as of December 2019 is 1.53 Mt with an average grade of 619.2 g/t silver for 30.5 million ounces and 10.75 g/t gold for 529,000 ounces. The Reserve cut-off grade is $215 NSR/t based on $1,250/oz gold and $18.00/oz silver with metallurgical recoveries of 95% for gold and 93% for silver.
On June 26, 2018, Yamana declared commercial production and in January 2019, Sandstorm began purchasing silver ounces from Cerro Moro. Yamana produced 6,322,864 ounces of silver and 120,802 ounces of gold in 2019. The mine plan involves a transition to a greater proportion of underground mining over the next three years including production from Zoe underground.
Exploration at Cerro Moro showed excellent opportunity for mineral resource growth near current mining operations, notably at the Zoe and Martina deposits. At Zoe, positive drill results showed good continuity at depth and at Martina, drilling defined the continuity of the main ore shoot generating new areas open to exploration.
The opening of additional mining faces and transition to increased mill feed coming from underground mining, at higher grades than the open pit ore, continued in the first quarter 2021. This trend will continue throughout 2021, with most of the ore to plant coming from Escondida Far West, Zoe, Escondida Central and Escondida West.
A US$18 million exploration budget for 2020 will include drill programs and multi-disciplinary fieldwork aimed at extending the mine life at Cerro Moro.