SSR Mining holds a 100% interest in the property through its wholly-owned subsidiary, SGO Mining Inc., which also acts as operator for Seabee Gold Operation (SGO).
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Summary:
Northern Saskatchewan forms part of the Churchill Province of the Canadian Shield and has been subdivided into a series of litho-structural crustal units. The Seabee Gold Operation (SGO) is located within the Glennie domain of the Proterozoic Trans-Hudson Orogen. All the main gold deposits at SGO are considered orogenic quartz-vein hosted lode gold deposits.
Delaney (1992) suggested that lithological heterogeneities between feldspar porphyry dikes and gabbros of the Laonil Lake intrusive complex are responsible for the localization and propagation of the shear zone. At Seabee, the structures trend between 045° and 085°, and dip north near vertically. Three discrete subsets of structures have been recognized trending at 070°, 085°, and 045°, with the 070° structures containing the auriferous veins. At Santoy, the structures trend between 340° to 315°, and dip moderately to the east. Vein geometry within the shear zones is commonly a combination of ‘S’ and ‘Z’ oblique and extensional types, and second order or Riedel shears.
Gold deposits in the SGO can be broadly assigned to three main geological domains:
• Santoy Mine Complex (SMC): The SMC is hosted in a sequence of Assemblage A mafic volcano-sedimentary rocks variably intruded by ca. 1875 Ma granodioritic rocks along an approximately 15 km roughly north–south trending sinistral to sinistral-reverse shear zone. The SMC occurs in an approximately 3 km long interpreted dilatant jog along this structure and is spatially associated with the ca. 1875 Ma Lizard Lake pluton.
• Laonil Lake Intrusive Complex: The historical Seabee and 5-1 mines occur along a series of conjugate shear zones within a coarsely layered ultramafic to mafic intrusion dominated by medium-grained, mesocratic gabbro.
• Porky: The Porky deposit area is a mineralized trend located near the nose of the Ray Lake synform, a 12 km long tightly folded and sheared contact separating siliciclastic rocks of the Porky Lake Group to the north from volcanic rocks to the south.
Gold mineralization at the Santoy mine complex is hosted within the Santoy Shear Zone (SSZ); a kilometer-scale shear zone with a roughly north-south strike that dips moderately to steeply to the east. Economic concentrations of gold occur in two main settings within this structure. The first, and historically most significant source of ore, is within dilatant portions of the SSZ. Mineralization in this setting is typified by diopside-albite +/- titanite altered, variably deformed, mafic volcanic rocks with sheeted and massive quartz veining up to 30 m wide with 2% to 10% sulphides (pyrite > pyrrhotite> chalcopyrite) +/- coarse visible gold. This style of mineralization is the dominant style of the Santoy 7, 8A/B, and 9 Veins. The second setting for gold mineralization in the SMC is within apophyses, and along the margin, of the Lizard Lake Pluton (LLP), which is a granodiorite intrusion deformed by the SSZ. Mineralization in this setting follows foliation parallel fracturing and, most significantly, the plunge of axial traces of secondary folding where competency contrast during deformation allowed for the formation of larger scale (1 m to 10 m) fracture networks to trap mineralizing fluids. Significant mineralization within the LLP is typified by highly silicified, variably albite altered and quartz veined granodiorite with 2% to 5% sulphides (pyrrhotite > pyrite > chalcopyrite). A greenish hue, interpreted to be an alteration of albite, tends to accompany the highest gold grades in this mineralization setting. This mineralization is typical of the GHW, SHW, and Santoy 8F mineralization.
Gold mineralization at the Porky deposits occurs along the western margin of the Ray Lake synform within a kilometre scale shear zone, the Pine Lake Shear Zone (PLSZ), that strikes east-southeast and dips moderately to the south. Gold mineralization at the Porky deposits is hosted in two distinct settings. The gold mineralization of greatest economic significance is hosted in 2 m to 20 m wide sheeted quartz veins with 2% to 10% sulphides +/- coarse visible gold (arsenopyrite > pyrite > pyrrhotite > chalcopyrite) within the metasedimentary rocks of the Porky Lake Group either immediately at the contact with the mafic volcanics above or, more prominently, footwall to a conglomerate unit usually 20 m to 60 m from the mafic-sediment contact. The best developed veining appears to correlate with the intersection of the axial planes of large (hundreds of metres) scale folding within the Porky Lake Group and the PLSZ. The second setting for gold mineralization is within broad (5 m to 60 m wide) intervals of deformed, calc-silicate altered, and locally sulphide rich (5% to 20% sulphide; pyrrhotite > pyrite > chalcopyrite +/- arsenopyrite and visible gold) mafic volcanic rocks. This setting tends to exhibit a lower gold grade than the veining internal to the sediments.
Gold mineralization in the now-closed Seabee Mine occurs in sub-vertical, roughly east-west striking, interconnected shear structures internal to a mixed unit of gabbro and quartz-feldspar dikes named the Laonil Lake intrusive complex. Gold mineralization is hosted dominantly in quartz veining with 2% to 7% sulphide (pyrite > pyrrhotite > chalcopyrite) +/- tourmaline, carbonate, and coarse visible gold. While the Seabee Mine is now closed, a number of subparallel structures to the ones which hosted the former mine have indications of economic mineralization in historic sampling.