ARIS MINING CORPORATION Aris Mining Corporation (Aris Mining) in compliance with the disclosure requirements of National Instrument 43-101 - Standards of Disclosure for Mineral Projects (NI 43-101) to disclose material updates to the mineral resource and mineral reserve estimates at the Segovia Operations resulting from Aris Mining's reviews and optimization of the geological interpretation and resource estimation methodologies, as well as the results of ongoing channel sampling and strategic exploration and infill drilling, optimization of mining, processing, productivity, labour structure, cost control, and updates to cost estimates and production plans. The Segovia Operations (the Property) are a historical and current mining operation comprising four active underground gold mining operations, which include El Silencio, Sandra K, Providencia, and Carla, together with other mineral resources and exploration targets, the Maria Dama processing facility that processes both ore produced from the Property's mineral reserves and material that is mined by smaller groups outside of the Property titles, tailings management facilities, and numerous historical mines, located in the department of Antioquia, Colombia. Mining has taken place on the Property for over 150 years with approximately 4.6 million ounces of gold reported to have been mined from the Property between 1869 and 2010.
Between 2011 and 2022, approximately 1.7 million ounces of gold have been produced at the Property's Maria Dama processing plant. The Property's El Silencio, Sandra K, and Providencia mines, the Maria Dama processing plant, and other key infrastructure are located within mining title RPP 140 in the municipality of Segovia. The Carla mine is located in mining title H6045005, approximately 10 kilometres (km) to the south in the municipality of Remedios.
Both of these municipality's community infrastructure has developed in response to the mining activities at the Property and the surrounding mining district. The Property is readily accessible by vehicle on national highways and sealed secondary roads leading 195 km to the northeast from Medellín. On September 26, 2022, GCM Mining Corp. (GCM Mining) completed a business combination with Aris Gold Corporation (Aris Gold) and the combined entity was renamed Aris Mining.
Aris Mining is the 100% owner and operator of the Property. There are around 1,280 drillholes and 203,261 channel samples defining the characteristics of the mineralized gold veins at the Property. Exploration and infill drilling, as well as channel sampling of the mineralized structures at the active mining operations takes place on an ongoing basis and are utilized for annual updates of the mineral resource and mineral reserve estimates, using assumptions based on actual operational results and updated production plans.
Annual drilling budgets have steadily increased since 2016, with exploration drilling plans guided by following the vein trends along strike and down dip as new surface and underground drilling platforms are constructed. In 2023, the number of development contractors was increased to allow for faster creation of drilling platforms. The strategic drill plan for 2023 included 84,500 metres (m) for infill drilling to increase mineral reserves and the life of mine plan, resource extensions at the producing mines, and strategic high priority vein targets located adjacent to the current mining operations. The Segovia Operations also provides drilling assistance to partner miners.
The drillhole and channel sample data cut-off date used for the mineral resource estimate is June 30, 2023, using approximately half of the 2023 planned drilling metres. The 2023 drilling program is still underway. Regionally, the Property is located in the Central Cordillera of the Colombian Andes and at a local level, mesothermal quartz sulphide veins comprising the Segovia gold deposit are hosted in diorites and granodiorites of the Segovia Batholith.
The Property geology is dominated by the Segovia Batholith, andesite to dolerite dikes, an extensive system of high grade gold mineralized quartz veins, and faulting resulting in offsets of the veins. The veins are controlled mainly by northeast trending, shallowly dipping faults associated with diorite to andesite dikes. The average width of the quartz veins is around 1.2 m and pinches and swells along strike and down dip.
The majority of the veins dip approximately 30° to the northeast, with a small number of steeply dipping veins. The mineral reserve estimate for the Segovia Operations effective September 30, 2023 is shown in Table 1-3. The mineral reserve cut-off grades were established for each area using a gold price of $1,700 per ounce, a metallurgical gold recovery of 95.2%, and cost assumptions based on actual operating results. The mineral reserve estimate utilized a gold cut-off grade of between 3.05 g/t and 3.40 g/t, depending on mining area.
The cut-off grade is applied to vein grades diluted to a minimum height that varies according to the mining area. Mining has taken place at the Property for over 150 years and the underground mining operation, Maria Dama processing plant, and associated mining infrastructure have been in place for many years. The ore at the Property has historically been mined from underground using labour intensive manual room and pillar mining methods from the 1.1 to 1.3 m wide veins that mostly dip between 30° and 35° degrees.
In 2023 longwall mining was introduced to increase mining productivity. Both methods follow the dip of the veins and provide for a high level of selectivity to maximize ore recovery and minimize dilution, and includes a primary room and pillar phase and a secondary pillar recovery phase. The minimum mining height is around 1.2 m. The total mining recovery from both phases is between 90% and 95%.
The total hoisting capacity is currently 3,220 tonnes per day (tpd). Mining is undertaken by both Aris Mining and by for-profit partnerships with local community based mining groups utilizing a compensation scheme based on the market price of gold that incentivizes higher grade ore, allowing for consistent margins from partner operated mining and allows the partner miners to participate in changes in the market price of gold. The primary room and pillar phase is undertaken by the owner mining teams and the secondary pillar recovery phase is undertaken by contractors, utilizing manual mining methods.
The underground mine has approximately 1,000 underground Aris Mining employees and around 980 Aris Mining employees working in a support capacity.
