The deposition of gold in the iron formation occurred when sulfur-rich auriferous hydrothermal solutions, ascending through favorable pathways in the shear zone and fault structures, reached the iron-rich minerals and reacted with them, collected iron from the magnetite and iron silicates and dumped iron and sulfur as sulfides, in the process also precipitating silica, carbonates and the gold.

The pattern and intensity of mineralization varies from place to place, from disseminations to massive ore shoots, with combined thickness of up to 25 meters.

The orebodies are composed of concentrations, bands, veins, veinlets and disseminations of fine-grained silica, carbonates and sulfides, which fill open spaces and totally or partially replace the host rocks. The initial data indicated a dominance of pyrrhotite at north and pyrite at south, followed by variable quantities of arsenopyrite, chalcopyrite and galena. Gold occurs in free form or included in the sulfides.

Open pit mining is currently being undertaken by new mine contractor Unienge & Modulo (U&M), the largest mining and locally experienced contractor in Brazil. The mining operations are based on the use of hydraulic excavators and a haul truck fleet engaged in conventional open pit mining techniques.

Excavated material is loaded to trucks and hauled to either the ROM, long term low grade or marginal stockpiles, the iron ore stockpile, or the waste dump. Ore excavation and haulage is monitored by quality control personnel employed by the Geology department and details of material movement are recorded by a radio dispatch system “Tecmine”. Oxide material is free dig with transitional material lightly blasted to loosen it for digging. Fresh rock is typically blasted on 4 m benches however 8 m benches are also fired. For wide sulphide ore lodes, the ore can sometimes be blasted separately if the shot is sufficiently large to minimize dilution. Normally ore and waste are fired together requiring the use of 8 m long poly pipes or Blast Vector Indicators (BVI) at each node of the ore polygon to determine post- blast movement. Ore sent to the ROM is stockpiled on fingers of oxide or sulphide within various grade cut-off categories to facilitate blending to achieve the desired oxide / sulphide proportions and grade.

The existing Tucano Mill consists of a jaw crusher feeding a single-stage, semi-autogenous grinding mill (SSAG), with the ore then being treated in a CIL plant. GPR is currently planning on mining and treating approximately 3.6 Mtpa of ore through the process plant, elution, and electrowinning facility to produce around 140,000 to 150,000 ounces of gold per year. The plant treats an ore blend of 80% oxide and 20% sulphide.

Ore is delivered to a run-of-mine (ROM) pad where ore of oxide and sulphide are stockpiled separately on fingers of specified grade ranges. Ore is fed to the crusher hopper by means of a front-end loader to achieve the planned sulphide / oxide blend and grade for the day. A vibrating grizzly allows the finer, sticky oxide ore to bypass the crusher. Crushing is achieved using a 1,220 mm x 1,070 mm single toggle jaw crusher with a closed side setting (CSS) of 125 mm. In addition to the jaw crusher, a separate Spent Ore Feeder is located in the emer ........