Mandalay Extends the Storheden Gold Deposit Adjacent to the Operating Björkdal Mine

"I am pleased to share progress on our 2023 initiatives at Storheden. This deposit has not been thoroughly explored in comparison to our extensive Björkdal deposit however it is showing promising signs of gold mineralization. In 2023, about 5,150 m were drilled across 22 drillholes targeting two separate objectives: depth extension with verification of system geometries and strike extension of the shear system.  

"This extensive drill testing program covered over 1.6 km and reached depths of approximately 100 m. It revealed many similarities to Björkdal and we are pleased to report success with high-grade gold discovered at depth and along strike. Moreover, this campaign also provided valuable insight into modelling the deposits.

In 2024, efforts at Storheden will prioritize diamond drilling to test the downward extensions of the mineralized zones and will be supplemented by generating regional targets using field mapping, soil sampling, and reconnaissance base-of-till drilling. Additionally, ongoing analysis of existing prospects will contribute to the development of new drilling targets and the continuation of exploration efforts based on the findings from previous campaigns."

During the summer seasons of 2022 and 2023 a total of 15,444 m, from 67 holes were drilled on prospective targets within the vicinity of the Björkdal mine (Figure 1). These targets were identified through analysis and interpretation of historical datasets and recent fieldwork conducted within Mandalay's active exploration permits. They represent areas of high potential for further mineral discoveries and underscore our commitment to advancing exploration efforts in the region.

The Storheden deposit is located roughly 600 m to the Northeast of the Björkdal mine (Figure 2-3). Mineralization was first identified in the area from "top of bedrock" geochemical drilling in 1987. Subsequently, while percussion drilling had been undertaken on the target delineating an extensive mineral system,  the active mine (Björkdal) has been the focus for exploration efforts leaving Storheden underexplored. In 2017, confirmation drilling and modelling undertaken by Mandalay lead to the granting of a mining concession in 2018 encompassing the confirmed mineralized zone.

During 2023 a total of 5,149 m were drilled across 22 drillholes. Two separate targets were identified for drill testing.

The primary aim of the 2023 deeps drilling campaign was to validate historical intercepts from percussion drilling and explore the down-dip extensions of the mineralized zone. Investigating the depth potential is important as the deposit is situated in part below the Bjorkdal tailings storage facility.

Previous models for the Storheden deposit have been limited by the lack of diamond drill core, with most data derived from percussion drilling. However, oriented core obtained from drilling during 2023 has made it possible to verify and extend upon existing models, demonstrating the down-dip continuity of mineralized veins controlled by a moderately, N to NE-dipping system of shears that runs parallel to the Skellefte-Vargfors contact.

Mineralized fluids appear to have utilized the rheological contact between relatively rigid volcanics of the Skellefte Group and weaker sedimentary sequences of the overlying Vargfors Group during deformation, in a similar manner to how shearing, fluid flow and mineralization in the Björkdal deposit is localized along the marble.

Mineralization in the Björkdal deposit has significant vertical continuity, with known mineralization dipping to the north-westalong a slope distance of 1500 m, while remaining open at depth. The potential for similar down-dip continuity of mineralization in Storheden remains open, with 2023 drilling demonstrating that mineralization extends beneath shallow historical intercepts.

Future programs will further test the down-dip potential of mineralization at Storheden, while extending the coverage of oriented drill core to verify historic data obtained from percussion drilling, particularly within the central section of the Storheden deposit. 

Gold mineralization occurs predominantly in quartz veins, ranging in thickness from less than a centimetre to more than several decimetres. Gold rich quartz veins are often associated with minor sulphides such as pyrrhotite, pyrite, chalcopyrite and arsenopyrite. In addition, scheelite, tsumoite and free gold are commonly observed in mineralised quartz veins Figure (figure 5 and 6).  

During 2023, a limited drill program totaling 1,116 m across 6 drill holes targeted the eastern extension of the marble horizon hosting the Björkdal deposit, which is also situated along the projected SE extension of the Storheden shear system (Figure 1).

No drilling has previously targeted this area, however, limited historic drilling to the east has intercepted minor mineralized quartz veins. Despite its promising structural setting, the 2023 drilling showed that this area lacks the pervasive veining characterizing the Björkdal and Storheden deposits. This is tentatively attributed to a thickening of the marble towards the northern margin of the Björkdal dome that may have accommodated strain during deformation, inhibiting fracturing and veining within in its hanging and footwall.

At Björkdal, all diamond drill core was logged and sampled by Björkdal geologists. Exploration drill hole samples were sent to CRS Laboratories Oy ("CRS") in Kempele, Finland for sample preparation and assaying.

Assaying was primarily conducted utilizing the Pal1000 cyanide leaching processes. For sulphide -rich samples, Fire-Assaying conducted at MSALABS (FAS-221, 50 g charge) in Canada, following sample preparations (crushing, pulverizing) at CRS Kempele. Mandalay's rigorous QA/QC program included the use of standard reference samples, blanks, duplicates, repeats, and internal laboratory quality assurance procedures. (see March 31, 2023, Technical Report entitled "Technical Report on the Björkdal Gold Mine, Sweden", available on SEDAR (www.sedar.com), which contains a complete description of drilling, sampling, and assaying procedures).

Chris Davis, Vice President of Operational Geology and Exploration at Mandalay Resources, is a Chartered Professional of the Australasian Institute of Mining and Metallurgy (MAusIMM CP(Geo)), as well as a Member of the Australian Institute of Geoscientists (MAIG) and a Qualified Person as defined by NI 43-101. He has reviewed and approved the technical and scientific information provided in this release.

Mandalay Resources is a Canadian-based natural resource company with producing assets in Australia (Costerfield gold-antimony mine) and Sweden (Björkdal gold mine). The Company is focused on growing its production and reducing costs to generate significant positive cashflow. Mandalay is committed to operating safely and in an environmentally responsible manner, while developing a high level of community and employee engagement.

Mandalay's mission is to create shareholder value through the profitable operation and continuing the regional exploration program, at both its Costerfield and Björkdal mines. Currently, the Company's main objectives are to continue mining the high-grade Youle vein at Costerfield, ramping up production from deeper Shepherd veins, both of which will continue to supply high-quality ore to the processing plant, and to extend Mineral Reserves. At Björkdal, the Company will continue to produce from the Aurora zone and other higher-grade areas in the coming years, in order to maximize profit margins from the mine.

This news release contains "forward-looking statements" within the meaning of applicable securities laws, including statements regarding the Company's expected production of gold and antimony and costs for the 2024 fiscal year. Readers are cautioned not to place undue reliance on forward-looking statements. Actual results and developments may differ materially from those contemplated by these statements depending on, among other things, changes in commodity prices and general market and economic conditions. The factors identified above are not intended to represent a complete list of the factors that could affect Mandalay. A description of additional risks that could result in actual results and developments differing from those contemplated by forward-looking statements in this news release can be found under the heading "Risk Factors" in Mandalay's annual information form dated March 28, 2024, a copy of which is available under Mandalay's profile at www.sedar.com. In addition, there can be no assurance that any inferred resources that are discovered as a result of additional drilling will ever be upgraded to proven or probable reserves. Although Mandalay has attempted to identify important factors that could cause actual actions, events or results to differ materially from those described in forward-looking statements, there may be other factors that cause actions, events or results not to be as anticipated, estimated or intended. There can be no assurance that forward-looking statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking statements.

Appendix

Table 1. Significant intercepts from the 2023 drilling programs at Storheden

Table 2. Drill hole collar details from the 2023 drilling programs at Storheden

Frazer Bourchier, President and Chief Executive Officer; Edison Nguyen, Director, Business Valuations and Investor Relations, Contact: 647.258.9722

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