GCM Mining Corp. announced that it has completed an updated Mineral Resource estimate for its Toroparu Project in Guyana with an effective date of November 1, 2021 and in accordance with the Canadian Institute of Mining Metallurgy and Petroleum ("CIM") Definition Standards incorporated by reference in National Instrument 43-101 - Standards of Disclosure for Mineral Projects (NI 43-101). GCM Mining also announced that Nordmin Engineering Ltd. (Nordmin) and SRK Consulting (U.S.) Inc. (SRK) have completed preliminary results of a Preliminary Economic Assessment (PEA) for the Toroparu Project effective November 26, 2021 and is currently finalizing the technical report to be prepared in accordance with NI 43-101 and filed on SEDAR and the Company's website in mid-January 2022. The MRE was prepared by Nordmin following a two-phase diamond drill program carried out by Gold X Mining in 2020-2021 which comprised a total of 20,750 meters in 114 drill holes. The updated MRE includes an open pit and a maiden underground resource estimate within the Toroparu Main & NW and SE deposits that are defined by multiple discreet northwest and east- west oriented high grade mineralized structures that intersect in a repeatable pattern over an estimated four kilometers of strike, 400-450 m in width, and 450-500 m in depth. The satellite deposits consist of the Southeast zone (SE) and the Sona Hill satellite gold deposits. Toroparu PEA and LoM Plan; A mining study and schedule was prepared by the technical professionals at SRK and Nordmin to create a LoM production schedule for the Toroparu Project that will initially comprise open pit mine operations and ultimately expand in year 10 to include underground mine operations. Sustaining capital expenditures related to the development of the underground mining areas will commence in year 9 (2032). The PEA also envisions a two-phase investment in processing facilities with an initial 7,000 tpd (2.55 Mtpa) Phase I nominal capacity in a gold leach plant based on gravity and CIL. Construction of a copper concentrator in years 4 and 5 (2027-2028) at a capital cost of approximately USD 103 million (included in sustaining capital expenditures and AISC data) will increase Phase II nominal capacity to 14,000 tpd (5.1 Mtpa) by Year 6 (2029) of the LoM. The copper concentrator will be based on gravity and copper flotation circuits and will facilitate the recovery of 141.3 Mlbs of copper over its 19 years of operation. The PEA LoM production schedule foresees a total of 107.3 million tonnes of mineralized material being processed over a 24-year mine life resulting in a total of 5.4 million ounces of gold produced at an average LoM total cash cost of USD 742 per ounce and an average LoM AISC of USD 916 per ounce. The initial capital cost, to be incurred between 2021 and 2023, is estimated to total USD 355 million. At an expected long-term gold price of USD 1,500 per ounce, total LoM undiscounted after-tax project cash flow from mining operations amounts to USD 1.7 billion. At a 5% discount rate, the net present value of the total LoM after- tax project cash flow amounts to USD 794 million. Before financing, the project has a 46% after-tax internal rate of return and payback of approximately two years.