Several genetic models have been suggested for Chapada, including: (i) a deformed and metamorphosed porphyry-type copper-gold deposit (Richardson et al., 1986; Oliveira et al., 2015), (ii) a deformed and metamorphosed volcanogenic disseminated sulphide deposit (Silva and Sá, 1986; Kuyumjian, 1989), and (iii) epithermal copper-gold deposit overprinted by metamorphic remobilization (Kuyumjian, 2000).

Currently, the most accepted metallogenetic model for Chapada is a metamorphosed porphyry model associated with skarn system. The magmatic hydrothermal system was generated in island arc stage setting (approximately 884 Ma to 879 Ma) and posteriorly overprinted by remobilization of orogenic fluids during Brasiliano events (ca. 630 Ma).

The porphyry, skarn, and epithermal system can be separated into three distinct mineralization styles, based on hydrothermal alteration and metal association:
- Copper-Gold Porphyry System (Chapada Corpo Principal, Corpo Sul, and Sucupira);
- Gold (Silver-Lead-Zinc) Distal Skarn (Suruca);
- Copper-Gold Proximal Skarn (Suruca SW).

The Chapada and Suruca deposits are located in the metavolcano-sedimentary sub-unit of Mara Rosa Sequence.

MINERALIZATION.
SURUCA.
The Suruca SW mineralization was discovered in 2017 exhibiting similar geological features to the Chapada deposit. The mineralization was delineated along a 2.1 km strike, 650 m width, and average depth of 50 m, and was partially exposed on surface.

The gold at Suruca is related to folded quartz veins/veinlets with sericitic and biotite alteration, rather than high sulphide concentrations. The second generation quartz veins/veinlets with sulphides (sphalerite + galena + pyrite), carbonates, and epidote also host gold which is related to zinc. The copper mineralization in the Suruca SW displays same features as Chapada, with sulphide disseminations and sulphides associated with stockwork quartz veinlets. In general, Suruca SW mineralization is formed predominantly by chalcopyrite and pyrite, with subordinate sphalerite and molybdenite.

Mineralization predominately pre-dates deformation so the gold (Suruca) and copper- gold (Suruca SW) zones are associated with skarn features, however, some structurally controlled features are also observed.

SKARN SYSTEM – SURUCA
The Suruca deposit is host to gold-zinc mineralization associated with sericite- chlorite-epidote carbonate (- biotite) and the argillic to propylitic alteration which corresponds to a skarn system.

According to Sillitoe (2014), the Suruca metal concentrations marked by zinc (sphalerite), lead (galena), and gold associated to epidote/calcite and/or garnet/amphibole rich schists, point to a distal gold (Ag-Zn-Pb) skarn system. These epidote-calcite rich schists are interpreted as skarns, which were subjected to amphibolite and subsequent greenschist facies regional metamorphism. Also, the possible presence of deformed and metamorphosed diorite porphyry in the copper- gold zone suggests that Suruca may be related to a discrete porphyry centre represented by Suruca SW.

At Suruca, pit design parameters are as follows:
For saprolite and oxide material types:
- 5 m bench height,
- 60° bench face angle,
- 4 m to 8 m safety berm,
- 15 m ramp width at maximum 10% gradient.

For sulphide material type:
- 30 m bench height,
- 70° bench face angle,
- 12 m safety berm,
- 25 m ramp width at maximum 10% gradient.

The start date of the Suruca oxide mine is currently under consideration by Yamana. Studies are ongoing to assess the Suruca oxide and sulphide pits as an integrated complex.

Currently, Suruca sulphide reserves are planned to be mined at the end of the Chapada mine life and ore from Suruca Sulphide will be fed into a modified Chapada processing plant at a rate of 8 Mtpa. However, alternative scenarios are currently being studied to process Suruca Sulphide with a standalone CIL or CIP plant.

SURUCA DEPOSIT OXIDE AND SULPHIDE ORES
Run of mine (ROM) material from the Suruca deposit, which consists of oxide and sulphide mineralization, will be processed separately. The oxide ore will be processed using conventional heap leaching technology, and the sulphide ore will be processed in the existing concentrator after some modifications.

SURUCA SULPHIDE ORE
Suruca sulphide ore is currently being planned to be processed through the existing Chapada plant, with some modifications, at the end of the Chapada mine life. There is also an option to construct a standalone CIL or CIP plant for processing the sulphide ore. Conceptual studies are ongoing.

SURUCA OXIDE ORE
Processing oxide from the Suruca deposit is planned according to the Suruca FS, prepared by Yamana and SNC Lavalin in February 2018 (Yamana and SNC Lavalin, 2018). Lundin is currently assessing the Project within the context of the Chapada complex.

The Suruca FS has finalized ........