Ethan Beardy HBSc thesis abstract

Thesis Title: 
Pyrite Characterization at Musselwhite Mine

Goldcorp’s Musselwhite mine is one of the largest gold deposits in Canada producing over 4 million ounces.  The mine consists of a variety of lithologies that are geochemically and structurally unique.  Musselwhite mine is situated within the North Caribou Greenstone Belt of the Superior Province.  The North Caribou Greenstone Belt is composed of eight metavolcanic and metasedimentary assemblages.  Musselwhite mine is located in the Opapimiskan Lake assemblage, which consists of wide range of mafic to ultramafic metavolcanic rocks. Interposed banded iron formation are found within the Opapimiskan Lake assemblage.  The mine geology is divided into five packages.  Packages consist of the Lower Basalts, South Iron Formation, Basement Basalts, Northern Iron Formation and the Upper Volcanics.  Musselwhite is an epigenetic structurally gold deposit.  Majority of gold mineralization is found in the iron formation, with two main styles of mineralization.  A quartz pyrrhotite flooding and sulphide replacement. 

The purpose of this project was to characterize pyrite and other associated sulphide minerals by examining their textural and mineralogical relationship to gold mineralization.  A total of fifteen core samples were collected by Musselwhite geologists.  The samples were prepared for petrography and SEM analysis.  Eleven of the fifteen samples were chosen for detailed analysis by the SEM.  A total of eight different lithologies were looked at in the study.  Petrographic descriptions were done for each sample.  It was found that all samples contained pyrrhotite displaying a variety of textures.  Five sample included pyrite with a range of textures.  Trace sulphides included chalcopyrite and arsenopyrite.  It was determined that gold was only correlated with pyrrhotite and quartz in this study.  There was no visible gold correlation with the pyrite.