Summary

Mine Type	Open Pit
Study Completed	Feasibility
Study in Progress	Feasibility Update
Stage	Construction
Commodities	Gold Silver Lead Zinc
Mining Method	Truck & Shovel / Loader
Project Timeline	...
Mine Life	...
Snapshot	The ATO Phase 2 Expansion will increase gold production and generate saleable concentrates of lead, zinc, and pyrite through the development of underlying fresh rock ores and the construction of a larger, conventional processing facility. As of 2024, the Phase 2 Expansion is progressing according to the updated timelines and budgets. Increases in annual capacity and metallurgical improvements are being reviewed with the EPC and engineering partners. A revised feasibility study is being developed in 2025, which will reflect the impact of higher current gold prices.

Deposit type

• Epithermal
• Breccia pipe / Stockwork

Summary:

The geology of the property consists of metamorphosed Devonian sedimentary rock overlain by a volcanic and sedimentary sequence of Permian age and remnant scraps of probable Jurassic volcaniclastic units, intruded by Jurassic plutons ranging from diorite to granite in composition and including rhyolitic phases mainly as dikes. Petrographic study suggests simple, single-pulse injections of the intrusions, with late-stage generation/expulsion of felsic phases and contemporaneous concentration of metal-rich fluids.

Mineralization at ATO is probably related to the Jurassic intrusive magmatic rocks as sources of heat, metals, and fluids. The main ATO system is associated with a stratigraphic unit that appears to be localized in a graben or collapse feature that is possibly but not certainly Jurassic in age; any stratigraphy could potentially be prospective for this style of mineralisation. The ATO mineralisation appears to have occurred as a protracted single-stage process in separately upward-flaring pipe-shaped bodies, with temperatures ranging from ~300-350°C at depth to possibly ambient temperature in surficial sinter.

Metal zonation: In a broad sense, metal zoning shows a clear, classic pattern of intrusion-centred copper (plus or minus molybdenum, tungsten, gold, and other elements) outward to country-rock hosted lead, zinc, and silver (plus or minus gold, arsenic, antimony, mercury, and other elements). It is presumed that this lateral zonation also occurs vertically, as evidenced by increasing copper values at depth in ATO.

It is believed that the ATO deposit is an epithermal gold and polymetallic deposit of transitional sulphides in breccia pipes in a Mesozoic continental rift zone in eastern Mongolia. Formation of breccia pipe: Tectonic-magmatic activities began to take place in the area around ATO deposit in Early Jurassic when hydrothermal and metasomatic alterations and mineralisation were formed in relation to intrusions and dykes. Absolute age of an intrusive massive located outside and east of ATO prospect area was determined to 189 million years.

The pipes that have been identified in the deposit are aligned in a row in a structure with a trend from southeast to northwest and form mineralisation with differing horizontal geochemical zonation with certain metallic concentrations. Noel White (2001) devised a pattern of flow of fluids based on this geochemical zonation similarity with that found adjacent to porphyry copper intrusions. White’s model postulates that the horizontal mineral zonation between the ATO pipes could originate from a large intrusion (such as a porphyry copper) located tens of kilometres away from ATO deposit.

Mining Methods

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Comminution

Crushers and Mills

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Processing

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Commodity Production

Operational metrics

Metrics
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Personnel

Job Title	Name	Profile	Ref. Date
.......................	.......................		Jul 29, 2025
.......................	.......................		Jul 29, 2025
.......................	.......................		Oct 27, 2021
.......................	.......................		Oct 27, 2021

Employees	Year
......	2021