The Florida Canyon Zinc Project is owned by Minera Bongará S.A and operated by Nexa Peru, a joint venture between Nexa Peru, Solitario Exploration and Royalty Corp. and Minera Solitario Peru S.A.C. (collectively, Solitario) in existence since 2006. As of December 31, 2024, Nexa Peru owns a 61.00% interest in this joint venture, which may increase up to 70.00% upon Nexa Peru’s satisfaction of certain conditions.
Nexa Resources S.A. owns 83.55% interest in Nexa Peru and therefore holds 50.97% of Florida Canyon Zinc project.
Summary:
The zinc-lead-silver mineralization of the Florida Canyon deposit occurs as sulfides hosted in dolomitized zones of the Chambara 2 Formation. Dolomite paragenesis and later sulfide mineralization are controlled by a combination of porosity, permeability and structural preparation. Metals occur in sphalerite and lesser galena, which contains silver. Minor mineralization is hosted in limestones, but the bulk of sphalerite and galena is hosted in dolomite.
In a number of core samples, the mineralization has very sharp contacts along the dolomitization boundary. Characteristic mineralization textures include massive and disseminated mantos, mineralization in dissolution breccias, collapse breccias and pseudobreccias. The different breccias and vein types are structurally controlled by faults of north-south and northeast- southwest direction.
The mineralization is characterized by the presence of sphalerite, galena and locally pyrite. Sulfide replacements occur in dolomitized limestone of variable grain sized and in solution breccias with white dolospar and lesser amounts of late generation calcite. Pyrite content is generally low, with percentages averaging less than 2% by volume. Sphalerite in mineralized sections has variable grain size from 0.1 to greater than 5 mm, with colors ranging from dark brown through reddish brown to light brown. It occurs as individual crystals or in massive form, sometimes displaying colloform textures with bands of slightly differing color zoning, indicators of polyphase hydrothermal deposition.
Early fine-grained sphalerite has evidence of later deformation and reactions to secondary mineralizing fluids. A second phase of more massive sphalerite mineralization is observed within the core of the deposit. These crystals are coarse-grained, regular, euhedral and show very little evidence of any post-depositional deformation. The sphalerite is contemporaneous with fine to coarse grained galena and is often overprinted with a later stage coarse-grained, euhedral galena.
The presence of zinc oxides, locally to considerable depths, is due to syngenetic oxidation, with later contributions of basin- derived connate water and movement of rainwater through fractures that leached the limestones and formed significant karst cavities.
The areas of current exploration interest are the Karen/Milagros, San Jorge and Sam Fault deposits. These mineralized zones are hosted in the dolomitized Chambará 2 sub-unit of the Pucará Group carbonates, bracketed by the Coquina and Intact Bivalve Marker beds. Geologic mapping and modeling includes refining the extents of Chambará 2, and further defining the steeply dipping feeder structures to predict additional zinc-lead-silver mineralization.
Local and regional geologic mapping, geologic drillhole logs, and the dome-shaped geometry of the deposit suggest the mineralization is hosted in a broad anticline structure. Florida Canyon is the collective name of the deposits in the Project area in Florida Canyon, and includes the Karen- Milagros, San Jorge, Sam Fault zones and similar mineralized strata between these areas.
Modeled manto zones are between 1 m and 9 m thick and occur over an area of about 1 km x 3 km and are open in all directions. Unmineralized gaps exist within the mineralized manto zones, as is typical for hydrothermal replacement deposits. Irregular steeply dipping replacement bodies also occur, frequently at the intersection of vein-like feeder structures and in karst-controlled mineralization.
Mineralization outcrops locally in a number of areas, and have been drilled at depths of up to about 450 m below ground surface. Zinc mineralization occurs as massive sphalerite (ZnS), and is locally oxidized to smithsonite (ZnCO3) and hemimorphite (Zn4Si2O7 (OH)2). Lead occurs in galena (PbS), cerussite (PbCO3) and anglesite (PbSO4).
An area of 20 km x 100 km extending from Mina Grande to north to 80 km south of the Florida Canyon deposit has become the focus of what is an emerging Mississippi-Valley Type (MVT) zinc and lead province, with many surface occurrences and stream sediment anomalies distributed throughout the Pucará Group. The main host rock of zinc and lead occurrences in the mineral district and Project area is dolomitized limestone, which may show karst or collapse breccia textures.
The structure at Florida Canyon is dominated by a N50º-60ºW trending domal anticline (or doubly plunging anticline) (SRK, 2014b). This anticlinal structure results in potential mining blocks of the manto deposits oriented along shallow dipping footwall/floors with dips ranging from 0° at the hinge to 25° near the middle to outer edges of the dome. The dip is as steep as 50° in the south of the deposit near the San Jorge exploration adit. Additionally, two steeply dipping mineralized bodies have been interpreted to exist. The first, known as San Jorge (zone F1), is located at the southern end of the deposit, and the other, known as SAM (zones 2 and 3), is located on the southwest edge of the deposit. The dip of these bodies ranges from 60° to 85° in San Jorge and 55° to 80° in the SAM body.