Summary:
There are three geologically distinct models explaining the geology of Hod Maden, two of which have specific geologic attributes whereas the third combines aspects of the first two models:
1. Structurally controlled intermediate sulfidation epithermal vein stockwork deposit with local semi and massive sulfide lenses.
2. Hybrid gold-rich volcanogenic massive sulfide (VMS)-epithermal deposit formed in shallow water with high-temperature clay alteration.
3. Cretaceous aged syn-VMS overprinted by younger high-level epithermal vein stockwork.
The Hod Maden deposit has three zones: the Main Zone, the South Zone, and the Russian Zone. The 2025 LOM plan considers the Main Zone only.
Deposit Dimensions
The Main Zone extends ~150 along strike at surface, has a true thickness of up to 70 m and a down-dip extension of ~400 m, and contains most of the high-grade gold and copper mineralization. Two phases of mineralization are dominant in the main zone: i) multiphase quartz-sulfide (pyrite+chalcopyrite) ± hematite+jasper breccia bodies; and ii) semi-massive to massive sulfides (pyrite+chalcopyrite) and gold mineralization.
The adjacent South Zone, which is structurally and mineralogically distinct, measures approximately 500 m along strike and 300 m in depth. Mineralization in the South Zone is discontinuous, and the mineralized zone is typically 10 m and locally up to 30 m thick. The South Zone is characterized by quartz-sulfide stockwork veins and hosts both copper and zinc-lead mineralization, indicating possible zonation within the gold-copper system.
The Russian Zone is located 1 km south of the Main Zone, and mineralization occurs over approximately 100 m of the strike length. The Russian Zone has remnants of early 20th-century Russian mining activity focused on high-grade copper polymetallic veins.
Deposit Setting
The Hod Maden deposit occurs in a steeply east-dipping Upper Cretaceous host sequence of andesite, dacite, and intermediate volcaniclastic rocks. The host sequence has a structural style that is typical of fault-bend folding and thrust repetition that is controlled by major north-northeast striking faults (Tripp 2023). Major faults occur parallel to the lithological contacts.
Structure
Hod Maden is characterized by a north-northeast trending, steeply dipping to sub-vertical structural corridor which is bound to the west by a north-northeast trending, east-dipping fault zone and to the east by a north-northeast trending, subvertical fault.
Fault Zones
The Hod Maden deposit is located within an NNE-trending structural corridor bound by the Hod Main Fault Zone (HMFZ) and the Hod East Fault Zone (HEFZ). Alteration in the area includes chlorite and jasperoid-quartz-pyrophyllite associations.
Weathering & Alteration
At the Hod Maden deposit, mineralization is structurally controlled and directly associated with argillic/phyllic hydrothermal alteration. The proximal alteration association is jasperoid-quartz-muscovite-black chlorite ± kaolinite-illite. The distal alteration consists of green chlorite-phengite ± smectite-calcite-epidote. SWIR data of surface samples from the Main and South Zones indicate the presence of acidic alteration (dickite and pyrophyllite) associated with mineralization as well as muscovite. These alteration patterns indicate temperatures of around 260°C (pyrophyllite) and between 300°C to 350°C (muscovite) (Tosdal 2023, Tripp 2023). Anhydrite in intergrown with pyrite-chalcopyrite and overprints mineralization. Anhydrite forms matrix to extensive micro-brecciation textures and is often associated with the jasperoid silica.
At vertical depths of greater than 450 m below surface, late-stage anhydrite brecciation of the multiphase Au-Cu breccias is common and results in the dilution of pre-existing Au-Cu grades (Artmin 2021). Alteration varies between the Main Zone and the South Zone. Pyrite-chalcopyrite is the dominant sulfide phase in the Main Zone. Alteration in the Main Zone is dominated by chlorite, with the flanking wall rocks typically displaying argillic and phyllic alteration assemblages. Pyrite is the dominant sulfide phase within the South Zone, with relatively minor chalcopyrite. In contrast to the Main Zone, sericite is the dominant alteration mineral. Hematite and jasper are present but in significantly lower abundances compared to the Main Zone.
Mineralization
Mineralization in Hod Maden is structurally controlled, which at surface can be seen as a gossanous outcrop with intense hydrothermal alteration. The outcrop is 300 m wide and extends for more than seven kilometers. Locally, mineralization has intense pyrite-chalcopyrite mineralization with a significant supergene clay alteration component. The inner element zonation consists of Au-Cu-Mo, while the outer element zonation consists of Zn-Pb-As (+Ag) and are structurally controlled (Tripp 2023). The highest Au-Cu grades are typically greater than 15 g/t Au (but can vary locally up to 100 g/t Au or more) and greater than 2% Cu. All mineralization at Hod Maden is sulfide-hosted; no oxide mineralization is present with only limited supergene enrichment near the surface and minor replacement of chalcopyrite by chalcocite. This is expected in mountainous terranes where erosion rates are high (Artmin 2021).
Main Zone
The Main Zone, especially its eastern margin, is characterized by the highest Au and Cu grades of the deposit. The zone of mineralization is typically >15 m thick. Two phases of mineralization have been identified:
1. Multiphase quartz-sulfide (pyrite+chalcopyrite) ± hematite+jasper breccia bodies.
2. Semi-massive to massive sulfides (pyrite+chalcopyrite) and gold mineralization The early-stage quartz-sulfide stockwork and brecciated jasperoid-hematite-bearing mineralization event is associated with pervasive chlorite alteration (Kuscu 2023). Coarse native gold is visible with the naked eye in jasperoid hematite-altered rocks with sulfide-quartz vein stockwork.
South Zone
Mineralization in the South Zone is hosted predominantly in dacitic porphyritic rocks, and comprises network quartz veins, veinlets, and breccia. The South Zone is characterized by comb-textured quartz-sulfide stockwork veinlets in structures that predominantly dip 80° to the north-northwest.
Two styles of base metal mineralization are present: (i) mineralization dominated by stratabound, structurally hosted Zn+Pb sulfides in the hanging wall, and (ii) sulfidebearing colloform veins in the footwall. Lead-zinc mineralization is also present in the Main Zone but is more prominent and continuous in the South Zone. It is unclear whether the base-metal mineralization represents a separate mineralization event or is part of a distal metal zonation in the Au-Cu system. Sphalerite-pyrite forms several stratabound horizons in the hanging wall subparallel to the massive sulfide and bedding in the steeply dipping stratigraphy. Sphalerite occurs either as discrete crystals in coarse clastic horizons or with wispy pyrite that is concentrated at the contact between sandstone interbeds (Tosdal 2023).
Russian Zone
The Russian Zone is 1,500 m south of the Main Zone. Historical data suggest small-scale historical mining was focused on narrow, high Cu grade polymetallic (Cu-Au-PbZn-Ag) veins. Stratigraphically, the Russian Zone lies 300 m above the Main Zone, indicating that deep drilling would be required to reach possible Main Zone-grade mineralization (Artmin 2021). The Russian Zone is not included in the Hod Maden Mineral Resource Estimate.
Commodity Production
While silver was measured in metallurgical testing, its grade in the final concentrate (28.7 g/t) did not meet payable levels (>30g/t). Therefore, production schedule does not include silver.
| Commodity | Product | Units | Avg. Annual | LOM |
|
Gold
|
Payable metal
|
koz
| 159 * | 1,609 * |
|
Gold
|
Metal in concentrate
|
koz
| | 1,650 * |
|
Copper
|
Payable metal
|
M lbs
| 21 * | 209 * |
|
Copper
|
Metal in concentrate
|
M lbs
| | 216 * |
|
Gold Equivalent
|
|
koz
| 189 * | 1,910 * |
|
Gold
|
Concentrate
|
kt
| 45 * | |
* According to 2025 study.