Oya Ak Kaykun, PhD

O. Ak Kaykun, D. Gregory
Earth Science Department, University of Toronto, Toronto, Ontario, Canada

The Archean Superior Province of the Canadian Shield is a key gold producer, accounting for approximately 88% of Canadas gold output. A significant area within this region is the Cadillac-Larder Lake Deformation Zone, located in the southern Abitibi greenstone belt in Northern Ontario. The Young-Davidson (YD) Mine, located in Matachewan, Ontario, represents the westernmost deposit in this zone. Gold at YD is primarily hosted in syenite, surrounded by a broad hydrothermal alteration halo. The main gold production targets are suphidized quartz-carbonate veins and sulphidized syenite veins associated with strong hematite alteration in the syenite. This study aims to refine the genetic model of the YD deposit and identify key evidence for gold precipitation through analyses at macro to micro scales.

This presentation highlights findings from the summer 2024 fieldwork, which included core logging and short wavelength infrared (SWIR) analysis of 17 drill holes across various sections of the ore zone. The samples represent diverse lithologies, mineralization types, and alteration zones. Preliminary analysis revealed that pyrite is the primary mineral associated with gold. Notably, high-grade gold is observed as inclusions within disseminated pyrite, particularly in areas with increased quartz veining. Additionally, assay results from the drill holes demonstrate a significant correlation between higher gold grades and increased pyrite mineralization. To identify controls on the formation and evolution of the Young-Davidson gold deposit, we performed a detailed investigation of pyrite textures (reflected light microscopy) and compared whole rock geochemical analysis and SWIR results.

The next steps will involve analyzing trace element content using LA-ICP-MS and sulfur isotopes (³²S, ³³S,³⁴S) to identify the source of the gold and determine which pyrite generations are linked to gold mineralization. These investigations aim to enhance the understanding of gold precipitation from hydrothermal fluids in the region and to develop predictive tools for estimating gold grades before mining.