Saturday, September 26, 2026
MiningNewsTerminal
Saturday, September 26, 2026 Admin

ERD.TO ·

Erdene Intersects High-Grade GOLD at Bayan Khundii Starter Pits

Drill Results

TSX: ERD | MSE: ERDN

www.erdene.com 1 [email protected]

ERDENE INTERSECTS HIGH-GRADE GOLD AT

BAYAN KHUNDII STARTER PITS

Highlights:

• Intercepted high-grade, near-surface gold in multiple holes in areas that are

expected to provide initial ore feed for the Bayan Khundii Gold Project

o 29.6 g/t gold over 4m, within 16m of 8 g/t gold (BKD-358)

o 68.0 g/t gold over 2m, within 10m of 14.4 g/t gold (BKD-361)

o 32.6 g/t gold over 2m, within 20m of 10.4 g/t gold (BKD-369)

o 67.5 g/t gold over 1m, within 7m of 11.8 g/t gold (BKD-354)

o 39.6 g/t gold over 1m, within 10m of 5.7 g/t gold (BKD-356)

Press Release

Halifax, Nova Scotia

2022.10.25

Erdene Resource Development Corporation (TSX: ERD | MSE: ERDN) (“Erdene” or the

“Company”) is pleased to announce results from Q3 2022 drilling in areas of high-grade

near-surface mineralization at the 100% owned Bayan Khundii Gold Deposit within the

Khundii Gold District (the “District”) in southwest Mongolia.

Quotes from the Company

“These results demonstrate the exceptionally high gold grades present in the areas

targeted for the first phase of the Bayan Khundii development,” said Peter Akerley,

Erdene’s President, and CEO. “This drill program confirmed and locally extended the near

surface, high gold grades identified at the Midfield Southeast and Striker South zones

since the delivery of the economic pit design for the feasibility study. The program also

collected ore for gravity processing test work. Preliminary studies concluded that gravity

processing compliments the Bayan Khundii CIP plant, bringing forward cash flow and

reducing operating costs.”

“Our team is also completing exploration and processing test work at the recent Dark

Horse and Ulaan discoveries, with further drill results anticipated by mid Q4,” continued

Mr. Akerley. “We continue to progress the Bayan Khundii Gold Project towards

development while searching for new discoveries across the Khundii Minerals District.”

Starter Pit Definition Drill Summary

The Q3 2022 Bayan Khundii drill program was designed to increase confidence in the

near surface high-grade gold mineralized zones targeted for initial development at the

Bayan Khundii Gold Project (“Project”). Drilling was also designed to gather ore to test

TSX: ERD | MSE: ERDN

www.erdene.com 2 [email protected]

amenability for gravity processing as an addition to the Project’s Carbon in Pulp (CIP)

plant.

In Q3 2022, Erdene completed a near surface drill program comprised of 25 PQ diamond

core holes, totaling 612 metres (averaging 17 metres vertical depth) in three target areas

within or near the planned Bayan Khundii economic pit. The objectives of this program

were to establish higher confidence in continuity of grade and geometry of the shallow,

very high-grade potential starter pit areas located at the Midfield Southeast, Striker South

and Striker zones of the Bayan Khundii deposit and to collect material for gravity

processing metallurgical test work.

The drilling program intersected multiple high-grade intervals, confirming the continuity of

near-surface high-grade gold mineralization at Midfield SE, Striker, and Striker South.

Multiple holes returned assays greater than 10 g/t gold as summarized in Table 1, below.

These results will be incorporated into updated models and used for start-up mine

planning purposes. Drill core from these holes will also be used for variability

metallurgical testing to confirm the viability of gravity recoverable gold in addition to the

currently planned CIP ore processing plant.

Table 1: Bayan Khundii Drilling Highlights

(Drill holes reporting interval(s) exceeding 10 g/t gold)

Hole ID From (m) To (m) Interval(1) Au g/t

BKD-352 6.5 26 19.5 2.51

Incl 18 23 5 6.20

Incl 19 20 1 15.06

BKD-354 0 7 7 11.79

Incl 5 6 1 67.54

BKD-356 6 25.6(2) 19.6 3.10

Incl 7 17 10 5.72

Incl 15 16 1 39.60

BKD-358 10.3 26(2) 15.7 8.03

Incl 12 16 4 29.60

Incl 14 15 1 100.46

BKD-361 5 15 10 14.36

Incl 10 12 2 67.95

BKD-363 12 18 6 1.97

Incl 17 18 1 10.05

BKD-366 23 29.5(2) 6.5 3.78

Incl 25 26 1 11.27

BKD-368 1 26(2) 25 1.00

Incl 2 3 1 16.96

BKD-369 0 20(2) 20 10.44

Incl 0 1 1 17.88

TSX: ERD | MSE: ERDN

www.erdene.com 3 [email protected]

Incl 4 7 3 27.04

Incl 9 11 2 32.57

Incl 15 16 1 10.18

BKD-370 2.5 20(2) 17.5 4.78

Incl 2.5 9 6.5 10.64

Incl 6 7 1 30.51

Incl 8 9 1 10.89

BKD-371 0 5 5 9.27

Incl 1 3 2 21.45

BKD-372 0 5 5 1.13

And 18 22 4 5.69

Incl 19 20 1 12.02

1. Reported intervals in this release are downhole apparent widths. Continued exploration is required to confirm anisotropy of

mineralization and true thicknesses

2. End of hole

Midfield Southeast Zone

Drilling within the Midfield Southeast (“MFSE”) zone consisted of nine infill holes targeting

high-grade gold mineralization within 25 metres of surface. Previous drill results from

MFSE include some of the highest-grade, shallow gold mineralization within the Bayan

Khundii deposit including 581.6 g/t gold over 1 metre, within 125.9 g/t gold over 5.5 metres,

beginning 11.5 metres down hole (BKD-288) and 25.6 g/t gold over 15.1 metres, including

5 metres averaging 74.34 g/t gold, beginning 15 metres downhole (BKD-274). Gold

mineralization at MFSE is related to southwest dipping quartz-hematite epithermal veins

which cross-cut the tuffaceous host unit of the Bayan Khundii deposit. Gold grades at

MFSE appear to be further enhanced by supergene enrichment, particularly in zones

where the primary gold bearing epithermal veins intersect along a sub north-south

trending structural plane representing a fault or shear. Gold enrichment along this plane

is typically contained within pervasive hematite altered and brecciated core with gold

grades locally greater than 100 g/t.

Striker and Striker South Zone

Drilling within the Striker and Striker South zones consisted of six and ten holes,

respectively. Drilling focused on further definition of previously reported near-surface,

high-grade gold mineralization within these potential starter pit locations including 14 g/t

gold over 8.3 metres, including 1 metre of 93 g/t gold, beginning 0.7 metres downhole

(BKD-44), 29 g/t gold over 15.1 metres, beginning 0.9 metres downhole (BKD-292), and

10 g/t gold over 7 metres, beginning 8 metres down hole (BKD-46). Gold mineralization

in both Striker and Striker South are related to southwest dipping quartz-adularia ±

hematite epithermal veins which cross-cut the tuffaceous host unit of the Bayan Khundii

deposit. Localized gold grades in the Striker South Zone exhibit very high grades (up to

353 g/t gold in hole BKD-292) within the contact aureole of a monzodiorite plug which

intrudes the tuffaceous host. Current interpretation of the gold grade enrichment around

TSX: ERD | MSE: ERDN

www.erdene.com 4 [email protected]

the intrusive body may be related to remobilization and subsequent redeposition of gold

associated with structural and hydrothermal processes during the monzodiorite

emplacement.

Metallurgical Test Work

The consideration of gravity as part of the process design circuit for the Bayan Khundii

ores has been studied since the earliest assessment. However, the discovery of high-

grade gold at surface at Dark Horse, combined with the exceptionally high-grade gold

intersections at MFSE and Striker South in 2020, prompted Erdene’s technical team to

complete further gravity oriented metallurgical test work in mid-2022. The results of that

work are summarized below.

A single composite sample was selected from drill core from holes at MFSE and Striker

South. This composite consists of quarter core from 21 one-metre intervals from 13 drill

holes with a calculated head grade of 15.1 g/t gold. The composite sample was analyzed

by Blue Coast Research from Parksville, BC, who have carried out the majority of the

metallurgical test work for the Bayan Khundii project. The test work consisted of a single

Extended Gravity Recoverable Gold (EGRG) test to evaluate the gravity recoverable gold

content of the composite sample. The test work included three stages of progressively

finer grind size (850 micron, 250 micron and 75 micron) with each stage passing through

a Knelson MD-3 concentrator to produce a concentrate. The tests resulted show 74.6%

of the gold was captured in the gravity concentrates.

The data from the EGRG test work was sent to FLSmidth Knelson for review and analysis.

Modelling conducted by FLSmidth was undertaken to predict gravity recovery using a

variety of different circuit configurations and anticipated plant design and throughput

parameters. Modelling showed that gold recovery could be achieved using concentrators

and shaker tables (50%) or concentrators and intense leach reactor (60%).

Based on the results of the work in mid-2022, six additional composites will be tested.

Sample material for these composites will be taken from the recently completed PQ

drilling reported herein. The additional test work will include a series of six variability

samples, representing different area and grades, that will undergo EGRG testing and well

as shaker table recovery testing. These data will assist in determining the most effective

gravity recovery circuit for the Bayan Khundii ore and is expected to provide support for

the inclusion of a gravity circuit at the front end of the CIP plant.

Erdene’s work to date suggests that a gravity plant may be brought online prior to

commissioning of a full CIP circuit, pulling forward cash flow, and rapidly repaying the

initial capital outlay. Furthermore, a gravity plant can be integrated into the CIP circuit,

increasing throughput by reducing load on elution circuit downstream. Gravity circuits are

readily available from a number of Chinese manufacturers, in a modular format, and can

be quickly and cost-effectively constructed.

TSX: ERD | MSE: ERDN

www.erdene.com 5 [email protected]

Projects Overview

Erdene’s deposits are in the Trans Altai Terrane, within the Central Asian Orogenic Belt,

host to some of the world’s largest gold and copper-gold deposits. The Company has

been the leader in exploration in southwest Mongolia over the past decade and is

responsible for the discovery of the Khundii Gold District comprised of multiple high-grade

gold and base metal prospects, one of which is currently being developed, the 100% -

owned Bayan Khundii Gold Project, and another which is being considered for

development, the 100%-owned Altan Nar Project. The Khundii District is currently defined

based on three gold and base metal systems related to shallow subduction Paleozoic

intrusive events within a 40 kilometre by 20 kilometre area in the Trans Altai Terrane

(formerly known as the Erden Terrane). Erdene’s 2022 exploration program is focused

on the two gold-dominant systems:

Bayan Khundii (Rich Valley):

Low sulfidation epithermal gold deposits and prospects (BK Deposit, Dark Horse, Ulaan

and Altan Arrow) overprinted on a high temperature, intrusive related alteration zone,

located along a 12-kilometres trend related to deep seated northeast trending structures

along a regional dilation zone and strike slip fault system. Current Resources1 for the BK

gold deposit include 585,100 ounces of 2.19 g/t gold Measured and Indicated (“M&I”)2

and 35,900 ounces of Inferred resources at 2.18 g/t gold. Resources have not yet been

established for the Dark Horse, Ulaan or Altan Arrow discoveries at Bayan Khundii.

An overview of the recent Dark Horse Mane and Ulaan discoveries at Bayan Khundii are

included below.

Dark Horse Mane

Dark Horse Mane is a 1.5-kilometre trend of alteration and gold mineralization discovered

in 2021. Located 2.4 kilometres north of the BK deposit, this zone begins at surface,

hosting supergene enriched gold zones including an exceptionally high-grade gold

bearing zone in the southern portion with values up to 195 g/t gold over 1 metre (AAD-

178) and ranging in thickness from 20 to 60 metres 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. Limited deeper

drilling has intersected wide zones of gold mineralization (e.g., AAD-57, 48 metres of 1.18

g/t gold from 194 metres down hole) associated with epithermal veins, white mica, and

sulfide alteration up to 230 metres vertical depth and remaining open.

The Company conducted data compilation, interpretation and drill hole targeting for the

broader Dark Horse prospect area in late 2021 and early 2022. This work focused on gold

anomalism, identifying feeder structures, shallow oxide gold mineralization, and areas

with similar characteristics to Dark Horse Mane, as well as the potential for deeper zones

of gold mineralization. This work has defined numerous drill targets for testing.

TSX: ERD | MSE: ERDN

www.erdene.com 6 [email protected]

Ulaan

The Ulaan gold target is a blind top discovery identified in Q3 of 2021. The discovery is

characterized by hundreds of metres of gold mineralization (up to 354 metres) over an

area 200 metres by 250 metres. Gold mineralization begins approximately 80 metres from

surface and remains open along strike to the west/northwest and at depth. Intervals

include 152 metres of 1.7 g/t gold in UDH-22 (from 85 metres) and 77 metres of 3.2 g/t

gold in UDH-21 (from 115 metres). Similar to the BK gold deposit, located 300 metres to

the east, the mineralizing event is characterized by exceptionally high-grade quartz ±

hematite and adularia veins and stockwork zones enveloped by the same gold bearing,

silicified, white mica altered lapilli tuff sequence. Stockwork zones identified in the

northern portion of the Ulaan discovery were the target of the initial Q2 2022 drilling and

helped to better define the orientation and extent of these exceptionally high-grade zones

where intervals of 5 metres of 20 g/t gold (UDH-14) to 1 metre to 156 g/t gold (UDH-21)

have been returned within broad high grade zones including 27 metres of 8.74 g/t gold

(UDH-21) and 34 metres of 5.43 g/t gold (UDH-14). In addition, the 2022 exploration

program included the extension of a series of existing drill holes to test for continuity at

depth. Expansion drilling at Ulaan Southeast is ongoing.

The southern portion of the Ulaan license has areas of anomalous gold-in-soil over an

area 3.5 kilometres by 1 kilometre. The underlying geology and alteration appear to be

analogous to the gold mineralization at Ulaan Southeast and Bayan Khundii, namely

tuffaceous units with white mica and silica alteration.

Altan Nar (Golden Sun): Intermediate sulfidation, carbonate base metal gold deposits

and prospects located along a 5.6-kilometre long alteration zone located within a regional

north-northeast trending structural corridor within which structural intersections or zones

of dilation provide the setting for the emplacement of broader zones of mineralization .

Current Resource for Altan Nar includes an Indicated gold-only resource of 317,700

ounces at a grade of 2.0 g/t gold and an Inferred gold-only resource of 185,700 ounces

at a grade of 1.7 g/t gold.

About Erdene

Erdene Resource Development Corp. 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 licenses and an exploration license in Southwest Mongolia, where exploration

success has led to the discovery and definition of the Khundii Gold District. Erdene

Resource Development Corp. is listed on the Toronto and the Mongolian stock exchanges.

Further information is available at www.erdene.com. Important information may be

disseminated exclusively via the website; investors should consult the site to access this

information.

TSX: ERD | MSE: ERDN

www.erdene.com 7 [email protected]

Qualified Person and Sample Protocol

Peter Dalton, P.Geo. (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 Ulaanbaatar, Mongolia. In addition to internal checks by SGS

Laboratory, the Company incorporates a QA/QC 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 5 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 +75 micron fraction and three 30-gram

samples of the -75 micron fraction from a 500 gram sample.

Erdene’s drill core sampling protocol consisted of collection of samples over 1 or 2 metre

intervals (depending on the lithology and style of mineralization) over the entire length of

the drill hole, excluding minor post-mineral lithologies and un-mineralized granitoids.

Sample intervals were based on meterage, 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 quart er-core

intervals, or a laboratory duplicate. Sample batches were periodically shipped directly to

SGS in Ulaanbaatar via Erdene’s logistical contractor, Monrud Co. Ltd.

Reported intervals are apparent thicknesses, i.e., downhole widths. The current Bayan

Khundii drill holes (reported in this release) are all dipping from 45 to 60 degrees and

oriented to intersect SW dipping WNW 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.

Forward-Looking Statements

Certain information regarding Erdene contained herein may constitute forward-looking

statements within the meaning of applicable securities laws. Forward-looking statements

may include estimates, plans, expectations, opinions, forecasts, projections, guidance, or

other statements that are not statements of fact. Although Erdene believes that the

expectations reflected in such forward-looking statements are reasonable, it can give no

assurance that such expectations will prove to have been correct. Erdene cautions that

actual performance will be affected by a number of factors, most of which are beyond its

control, and that future events and results may vary substantially from what Erdene

currently foresees. Factors that could cause actual results to differ materially from those

in forward-looking statements include the ability to obtain required third party approvals,

market prices, exploitation, and exploration results, continued availability of capital and

financing and general economic, market or business conditions. The forward -looking

statements are expressly qualified in their entirety by this cautionary statement. The

TSX: ERD | MSE: ERDN

www.erdene.com 8 [email protected]

information contained herein is stated as of the current date and is subject to change after

that date. The Company does not assume the obligation to revise or update these

forward-looking statements, except as may be required under applicable securities laws.

NO REGULATORY AUTHORITY HAS APPROVED OR DISAPPROVED THE

CONTENTS OF THIS RELEASE

Erdene Contact Information

Peter C. Akerley, President and CEO, or

Robert Jenkins, CFO

Phone: (902) 423-6419

Email: [email protected]

Twitter: https://twitter.com/ErdeneRes

Facebook: https://www.facebook.com/ErdeneResource

LinkedIn: https://www.linkedin.com/company/erdene-resource-development-corp-/