The gold deposit is orogenic mesothermal, associated with the development of shear zones. The host rocks belong to the Upper Archaean Crixás Group. Gold mineralisation is associated with meta-sediments and meta-volcanics rocks from the Ribeirão das Antas and Rio Vermelho formations respectively. The Crixás Greenstone Belt is surrounded by granitic gneiss terrains from the Anta and Caiamar complexes and meta-sedimentary rocks from the Santa Terezinha Group, which is part of the Goiás magmatic arc.

The mine complex is located in the Crixás Greenstone Belt sequence, in the central portion of Brazil, and the main host rocks are the meta- sedimentary sequences with association with meta- volcanic meta-basic rocks. The mineralisation at MSG is associated with quartz veins and massive to disseminated sulphides in meta-sedimentary, meta- volcaniclastic and meta-basalt rocks, with differing degrees of hydrothermal alteration developed over orogenical stacked thrust layers (duplexes).

Two main deformation events are responsible by mineralisation style. The first event is the principal thrust event (east over west, called D1) and develops an irregular thrust ramp geometry. This event stacked and inverted the stratigraphic sequence. The second event (D2) was the Santa Terezinha sequence (Magmatic Arc) thrusting over Crixás Greenstone Belt, folding the rocks (F2) and generating the structures that control the gold mineralisation, generally parallel to the fold axis ........

Serra Grande comprises three mechanised underground mines, Mina III, Mina Nova and Mina Palmeiras, and an open pit as well as a dedicated metallurgical plant.

Three mining methods are used underground: sub-level stoping (bottom-up and top-down), cut and fill, and room and pillar. The open pits use standard drill and blast, followed by truck load and haul.

Serra Grande operates a single TSF, which will support the LOM production.

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