Mr. Peter Akerley reports

ERDENE REPORTS BAYAN KHUNDII GOLD PROJECT EXPLORATION RESULTS FROM DARK HORSE PROSPECT

Erdene Resource Development Corp. has released results of recent exploration at the Dark Horse gold prospect, part of the greater Bayan Khundii gold project. The Dark Horse gold prospect is located approximately two kilometres north of the planned Bayan Khundii (BK) open pit in the Khundii minerals district, in southwest Mongolia.

Quotes from the company

"Since discovery in early 2021, Erdene has defined a 1.5-kilometre mineralized trend at the Dark Horse Mane, including the very-high-grade Dark Horse Mane South deposit at the Bayan Khundii gold project," said Peter Akerley, Erdene's president and chief executive officer. "Results from the most recent exploration work open up several new targets for follow up in the 20-square-kilometre greater Dark Horse prospect area that show potential to host high-grade gold mineralization.

"Located just two kilometres north of the initial Bayan Khundii open pit, ore from Dark Horse Mane will be incorporated into the feasibility study update, expected to be announced in the coming weeks," continued Mr. Akerley. "Growing resources at Dark Horse will strengthen the already strong economics of the Bayan Khundii gold project."

Exploration program results

Erdene recently completed a shallow drilling and geophysical exploration program across the greater Dark Horse prospect at the Bayan Khundii gold project. The program included an 18-hole scout exploration drilling campaign, totalling 1,040 metres, and a gradient array induced polarization (IP) geophysical survey covering nine square kilometres over the core of the greater Dark Horse prospect. The program was primarily designed to test for near-surface oxide-related gold mineralization, similar to the Dark Horse Mane deposit, and to identify targets for follow-up deeper drilling.

The program identified multiple areas of near-surface gold and indicator element anomalism, with 12 holes intersecting anomalous gold (greater than 0.1 gram per tonne (g/t) and up to 5.8 g/t Au (gold)) and 16 holes returning indicator element mineralization locally over wide intervals up to 55 metres. Gold, together with antimony, arsenic and molybdenum geochemical anomalies, are characteristic of the Dark Horse deposit, and were instrumental in the initial discovery of high-grade, near-surface gold mineralization at the Dark Horse Mane. These results suggest gold mineralized hydrothermal fluids, carrying gold and other related elements, affect a wide zone within the greater Dark Horse area.

Highlight gold intersections from the program are provided in the table entitled "Dark Horse Q3 2023 drilling highlights."

Hole AAD-222 was a stepout from previous north-south-trending trenches and drill holes that returned up to 70.2 g/t gold over two metres (AAD-12). The intersection of mineralization in AAD-222 extends the area of known gold mineralization approximately 135 metres along trend to the southwest, increasing the gold mineralization strike length to 250 metres. Mineralization in this zone remains open along trend for hundreds of metres. Additionally, mineralization remains open at depth, with exploration to date testing to a maximum depth of 110 metres.

Hole AAD-226 was a near-surface follow-up hole to AAD-110 that returned seven metres of 1.46 g/t gold in the area of East Mane. Hole AAD-226 intersected near-surface oxide gold mineralization above the previously intersected mineralization in AAD-110. The newly acquired gradient array IP data show that the East Mane prospect is located along a strong north-south lineation, parallel to the Dark Horse Mane trend, that extends over three kilometres (the north-south width of the IP survey area). This lineation may represent a previously unidentified north-south structure. Wide-spaced drilling along this lineation, as well as rock and soil geochemical surveys, have returned gold and thick intersections of indicator element anomalism. Follow-up exploration will be undertaken later in the year.

Hole AAD-235 was drilled in the Altan Arrow area, where earlier drilling and trenching returned strong gold, silver and base metal mineralization along a 1.2-kilometre-long northeast trend. In addition to the gold mineralization, AAD-235 returned two metres averaging 65 g/t silver, 0.34 per cent lead and 0.06 per cent molybdenum (from 42 metres to 44 m downhole). This combination of elements is more typical of deeper epithermal mineralization, closer to a possible porphyry centre at depth in the untested northeast portion of the Khundii mining licence. Anomalous molybdenum mineralization in soil sampling extends along trend two kilometres to the northeast, an area that has not been drilled tested to date.

Gradient array survey

A detailed gradient array IP survey, focusing on defining near-surface (up to 100 metres depth) chargeability and resistivity targets was completed over a nine-square-kilometre area, centred on Dark Horse Mane.

The gradient array survey shows the major northeast trend of structures, as well as a strong north-south trends, supporting the structural interpretation of extension zones opening along a set of northeast-trending major strike-slip faults, hosting north-south trends of mineralization identified at Dark Horse Mane. A number of parallel zones with similar geophysical signatures to known mineralization at Dark Horse Mane have been identified. These areas are under tested or untested by drilling, including the strong north-south lineation through East Mane, intersected by AAD-226.

Also of note are two north-south, elongated gradient array chargeability/resistivity anomalies, 400 m and 700 m, respectively, west of Dark Horse Mane South. These zones have the same gradient array IP signature as Dark Horse Mane South, and similarly lie just north of a major northeast-trending structure interpreted to be a deep-seated structure and likely conduit for mineralizing fluids. These new geophysical anomalies represent strong new exploration targets. Together with other geological and geochemical data, all zones of gradient array IP anomalism will be assessed and prioritized for future drilling.

Gold mineralization at Bayan Khundii

The area of known gold mineralization within the Bayan Khundii project area extends from Ulaan in the southwest, through the Bayan Khundii gold deposit and north throughout the greater Dark Horse prospect, covering an area of over 40 square kilometres. Gold mineralization is focused along northeast-southwest and related north-south structures, that acted as conduits for mineralized fluids from deep magmatic sources, potentially related to porphyry centres at depth.

The variety of minerals associated with the gold mineralization, and the large area of mineralization, suggests either multiple magmatic/porphyry sources, varying depths of mineralization (with subsequent varying levels of uplift and erosion to expose different depths of mineralization at the current surface), or both.

The greater Dark Horse prospect (approximately 20 square kilometres) is located in the northern portion of the Khundii mining and Ulaan exploration licences, and is characterized by elevated gold-in-soil anomalism with multiple surface rock chip, trench and drill core samples assaying greater than one g/t gold. Trace element anomalism, geophysical anomalies related to alteration and mineralization, structures interpreted to represent conduits for mineralizing fluids, and alteration signatures supporting an epithermal mineralization model characterize the greater Dark Horse prospect area.

The Dark Horse Mane prospect is associated with a north-south-trending, linear structural corridor which intersects deep-seated northeast-trending transform faults, believed to be a conduit for primary mineralizing fluids. The north-south structure has been traced over five kilometres, from the southern portion of the Bayan Khundii deposit to the northern extension of Dark Horse Mane. Gold mineralization is hosted within strongly altered tuffaceous and volcanoclastic rocks, crosscut by quartz and quartz-hematite veins, and stockwork zones. The Dark Horse Mane shallow oxide zone begins at surface, hosting supergene enriched gold zones with values up to 195 g/t over one metre and ranging in thickness from 20 m to 60 m vertical depth, with locally deeper oxidation along fractures. The high-grade oxide body exhibits strong continuity along a north-south strike. Mineralization remains open along strike and at depth.

The near-surface oxide gold zones discovered at Dark Horse Mane are the result of oxidation of sulphide-bearing epithermal veins and hydrothermal breccias within white mica altered host lithologies. Limited deeper drilling has intersected gold-bearing epithermal veins and associated white mica and sulphide alteration zones to a depth of up to 230 metres vertically, that remains open at depth. The gold mineralization near surface at Dark Horse Mane is related to broader areas of structurally controlled alteration and mineralization believed to be connected to feeder structures, distributing gold-bearing fluids over a wide area as these fluids approached the paleo surface. Evidence for these feeder structures includes a series of exposed residual quartz lithocaps, associated locally with increasing copper anomalism at depth, interpreted to predate the gold mineralization. These lithocaps are distributed along dominant northeast-trending structures believed to represent transform faults and potentially feeder conduits from a magmatic porphyry source at depth. The highest-grade gold-bearing oxide zones at the southern end of the Dark Horse Mane are located proximal to the residual quartz lithocaps and hosted within tuffaceous to porphyritic volcanoclastic units.

Continued success in identifying gold mineralization in the greater Dark Horse area and beyond, together with increased understanding of the controls on mineralization, suggest high potential for the discovery of additional gold mineralization both near surface and at depth across the Bayan Khundii project area. It is anticipated that by incorporating the new exploration data into the company's geological model, additional high-priority targets will be identified. A return to drilling at the Bayan Khundii project, including at Dark Horse, is expected later in the year.

About Erdene Resource Development Corp.

Erdene is a Canada-based resource company focused on the acquisition, exploration and development of precious and base metals in underexplored and highly prospective Mongolia. The company has interests in three mining licences and an exploration licence in southwest Mongolia, where exploration success has led to the discovery and definition of the Khundii minerals district.

Qualified person and sample protocol

Peter Dalton, PGeo (Nova Scotia), senior geologist for Erdene, is the qualified person as that term is defined in National Instrument 43-101, and has reviewed and approved the technical information contained in this news release. All samples have been assayed at SGS Laboratory in Ulan Bator, Mongolia. In addition to internal checks by SGS Laboratory, the company incorporates a quality assurance/quality control sample protocol utilizing prepared standards and blanks. All samples undergo standard fire assay analysis for gold and ICP-OES (inductively coupled plasma optical emission spectroscopy) analysis for 33 additional elements. For samples that initially return a grade greater than five g/t gold, additional screen-metallic gold analysis is carried out, which provides a weighted average gold grade from fire assay analysis of the entire plus-75-micron fraction and three 30-gram samples of the minus-75-micron fraction from a 500 gram sample.

Erdene's drill core sampling protocol consisted of collection of samples over one m or two m intervals (depending on the lithology and style of mineralization) over the entire length of the drill hole, excluding minor postmineral lithologies and unmineralized granitoids. Sample intervals were based on metreage, not geological controls or mineralization. All drill core was cut in half with a diamond saw, with half of the core placed in sample bags and the remaining half securely retained in core boxes at Erdene's Bayan Khundii exploration camp. All samples were organized into batches of 30, including a commercially prepared standard, blank, and either a field duplicate, consisting of two quarter-core intervals, or a laboratory duplicate. Sample batches were periodically shipped directly to SGS in Ulan Bator via Erdene's logistical contractor, Monrud Co. Ltd.

Reported intervals are apparent thicknesses, that is, downhole widths. The current Bayan Khundii drill holes (reported in this release) are all dipping from 45 degrees to 60 degrees and oriented to intersect southwest-dipping west-northwest-trending gold-bearing veins. Additional study is required to confirm true widths. Reported grades for intervals are weighted averages based on length of sampling intervals. No top cut has been applied, however, all intervals greater than 10 g/t gold and 100 g/t gold are reported individually for clarity.

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