CHARACTERIZING THE AURIFEROUS SYSTEM AT PORKY LAKE WITHIN THE PINE LAKE GREENSTONE BELT, NORTHERN SASKATCHEWAN, WITH A FOCUS ON PETROGRAPHY AND MINERAL CHEMISTRY
Gold mineralization occurs within the Pine Lake greenstone belt in several known and prospective deposits in northern Saskatchewan, Canada. The mineralization systematics at some of these locations within the Seabee Gold Operation, including the Porky Main and Porky West deposits, are poorly constrained; however, they are adjacent to the recently decommissioned Seabee mine, existing mill infrastructure, and active mining at the Santoy Mine Complex, adding to their prospectivity. The Porky deposits are spatially associated with a shear zone separating the mafic volcanic rocks (Assemblage A) from the arenaceous metasedimentary rocks (Porky Lake Group) and are hosted in a variety of rock types, for which petrographic and geochemical characterization was previously lacking. The gold mineralization is associated with calc-silicate alteration of the mafic volcanic unit and with smoky quartz veins in the Porky Lake Group. To further characterize the Porky deposits, mineralized drillcore samples were analyzed to characterize the mineralogical and trace-element characteristics of sulfide-gold mineralization. Multiple sulfide mineral generations are defined in the construction of a mineral paragenesis chart that defines five phases of sulfide mineral formation (including pyrite), three of which are associated with gold mineralization. The sulfide generations associated with mineralization include sieve-textured Py3-Po2-Ccp2 ± Sp-Gn in the pervasive calc-silicate alteration, oscillatory zoned Apy-Py4a/b-Po3-Ccp3 ± Ilm1 in the smoky quartz veins, and with the remobilized Py6a/b, where Au occurs in fractures of earlier sulfide mineral generations. Similar paragenesis observations exist for the Santoy mine and Fisher property, supporting an interconnected, multi-stage orogenic gold system throughout the belt. Lastly, we report new geochronology of a ca. 1851 Ma granodiorite that intrudes the Porky Lake Group, refining previous age constraints.
Geology, Orogenic gold, Saskatchewan, Seabee Gold Operation, Geochronology, Geochemistry, Trace-element analysis, Porky Lake, Mineralization, Glennie domain, Trans Hudson orogen, Electron Microprobe, Laser Ablation Inductively Coupled Plasma Mass Spectrometry, Petrography
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