GCM Mining Corp. has completed updated mineral resource and mineral reserve estimates for its Segovia Operations, prepared in accordance with the Canadian Institute of Mining Metallurgy and Petroleum (CIM) Definition Standards incorporated by reference in National Instrument 43-101 with an effective date of 31 December 2021.
Highlights of the updated mineral resource estimate as of 31 December 2021 (the 2021 MRE) include:
- Total measured and indicated resources increased to 4.6 million t at a grade of 11 g/t totalling 1.62 million oz of gold (Au), up 14% from last year.
- Total inferred resources increased to 5.3 million t at a grade of 9.9 g/t totalling 1.70 million oz Au, up 41% compared to last year.
- The company more than replaced the mineral resources it mined in 2021 representing the sixth consecutive year that it has, at a minimum, replaced the mineral resources mined at its Segovia Operations. El Silencio and Sandra K were the primary areas of growth within the 2021 MRE.
- The 2021 MRE continues to reaffirm confidence in the high-grade nature of the Segovia gold deposits which have been in continuous operation for more than 100 years.
- The brownfield exploration programme, which focused on exploration for new resources at the brownfield exploration targets on the 24 veins within the Segovia mining title that are not currently in production, yielded its first addition in the 2021 MRE with inferred resources reported at the Vera Project.
The 2021 MRE reflects an increase in the diamond drilling database of 412 holes for 93 868 m compared to December 2020. A new vein has been added to the mineral resource at the historical Vera mine, which includes an additional 63 holes for 9640 m (including 27 holes for 7509 m of new drilling), bringing the total cumulative drilling database to 2553 holes for 378 846 m. All diamond core drilling during 2021 has been logged and sent for preparation at the SGS laboratories in Medellin, with associated Quality Control Programs. In addition to the drilling, a total of 13 001 channel samples totalling some 11 485 m in length were added to the database in 2021, including 4588 channel samples totalling 3326 m from historical FGM sources, and 92 channels for 106 m of GCM check sampling for Vera.
The 2021 MRE was prepared using a block model constrained with 3D wireframes of the principal veins, which have been sub-domained using high-grade mineralisation wireframes to constrain the influence of higher grade material. Assays are capped prior to compositing. Values were interpolated using ordinary kriging for well informed areas and inverse distance squared methodology for smaller veins with limited data. All models have been depleted using projections of the mining faces through the entire width of the veins. Classification has been applied based on a combination of data quality, confidence in the spatial location, and confidence in the mining depletion shapes. Only material reporting above a cut-off of 2.9 g/t over a minimum stope width of 1 m has been included in the 2021 MRE. The MRE for Las Verticales has not been updated as no new information is currently available and the previous estimate for this project remains valid.
Ben Parsons, Principal Consultant (Resource Geology) with SRK, prepared the Segovia MRE according to CIM Definition Standards and will be supported by a NI 43-101 independent report.. Parsons is a Qualified Person as defined by NI 43-101. The NI 43-101 independent report will include detailed information on the key assumptions, parameters and methods used to estimate the mineral resources.
SRK has also completed preliminary results of an updated preliminary feasibility study (Segovia PFS) for the Segovia Operations effective 31 December 2021 and is currently finalising the technical report. At 31 December 2021, Segovia’s reported mineral reserve totalled approximately 745 000 proven and probable oz Au, based on 2.3 million t of material at an average head grade of 10.1 g/t, compared with 633 000 oz at the end of 2020 based on 2.2 million t of material at an average head grade of 9 g/t.
For the Segovia PFS, SRK included the geological and resource modelling of the various deposits and mining areas that comprise the operating mine site of the Segovia Operations. A mining study and schedule was prepared by both SRK’s and the company’s technical professionals to create a LOM production schedule, including both company-operated areas and contractor-operated areas within the company’s Providencia, El Silencio, Sandra K and Carla mines. The Segovia PFS production schedule includes only proven and probable reserves, and as such, the annualised level of production over the seven-year projected mine life in the Segovia PFS may be lower than the company’s current expectations. This is largely due to the exclusion of inferred resources in the LOM production schedule in the Segovia PFS which the company currently mines and intends to continue mining in the future. In addition, the material processed under operating contracts at the company’s Maria Dama plant from the small-scale mines located in the company’s mining title is not included in the LOM production schedule in the Segovia PFS as it falls outside the company’s mines and is therefore not included in the company’s 2021 MRE or mineral reserves.
Fernando Rodrigues, BS Mining, MBA, MAusIMM, MMSAQP Practice Leader/Principal Consultant (Mining Engineer) with SRK, prepared the Segovia mineable reserve according to CIM Definition Standards and will be supported by a NI 43-101 independent report.. Rodrigues is a Qualified Person as defined by NI 43-101. The NI 43-101 independent report will include detailed information on the key assumptions, parameters and methods used to estimate the mineable reserve.
Read the article online at: https://www.globalminingreview.com/exploration-development/25032022/gcm-mining-provides-annual-update-to-segovias-mineral-resource-and-reserve-estimates/