Olympias is a gold-rich polymetallic sulphide replacement-style deposit formed within strongly deformed metamorphic rocks of the Paleozoic Kerdylia Formation of the Serbo-Macedonian Massif. The orebodies are hosted by marble interlayered within a sequence of biotite-gneiss, amphibolite and orthogneiss. The deposit consists of multiple stratabound orebodies that overall plunge shallowly to the southeast for over 1.8 km, subparallel to the orientation of fold hinges and a locally developed intersection lineation.

Olympias is an example of a polymetallic carbonate replacement deposit, however it is somewhat unusual due to the high Au content of the deposit (cf. Siron et al. 2019). Key characteristics of this class of deposit include carbonate host rocks, massive sulphide mineralization, spatial and temporalrelationship with magmatism and zoned metal distribution (Megaw, 1998). Geochronological and paragenetic relationships described by Siron et al. (2016, 2018) confirm that Olympias was coeval with late Oligocene (~ 25-22 Ma) magmatism in the region although the source intrusion has not been identified. Nonetheless, carbon and oxygen isotopic data support a magmatic fluid source (Siron et al. 2019), and the zonation towards Mn-rich alteration in the upper levels of the deposit (North Zone) are consistent with shallow, distal portions of a magmatically derived carbonate replacement system.

The Olympias deposit massive sulphide lenses are grouped into three ........

The Olympias mine is a 100% underground (“UG”) mining operation extracting ore from East, West, Flats, and Remnants zones. In 2022, mining will concentrate on the West, East and the beginning of the Flats zones with a small proportion from the Remnants area. Mining is currently at a rate of 430 ktpa ROM ore. There is a planned production increase culminating in a steady-state rate of 650 ktpa by 2025. In order to achieve the planned higher production, the Company is taking steps to improve equipment availability / utilization and worker productivity. There are also further capital requirements to allow the process plant to treat 650,000 tpa.

Mining at Olympias will be a combination of drift and fill (“DAF”) and another method may be introduced: longhole open stoping (“LHOS”). LHOS will be confined to areas where geometry and ground conditions support the use of this more productive method. LHOS excavations will be limited to maximum dimensions of 10 m wide and 30 m high. The maximum length varies depending on the height and average rock quality. Blind uppers will be used for drill and blast with no top accesses to minimize ore development requirements. DAF mining utilizes the overhand mining method. Stopes are accessed on the foot wall side from the main ramp starting at the bottom of each 20 m high stoping block. Each lift is mined 5 m high, with each panel limited to 5 m wide with consideration given to 6m high and 6 m wide stopes.

Ground support is a ........

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