A large field of 'granitoid' rock was discovered in 2022 west of the Broadview Mine, and has not been seen anywhere else at Thor. Although the bedrock source of these boulders remains ellusive, they could provide valuable insight into a concealed intrusive body at Thor.
VLF and ground magnetic surveying may have identified this formation in an area that is extensively covered by colluvium. It forms a dyke-like body that extends west of the Broadview Mine, and would be expected to be derived from a much larger intrusive body below the Thor epithermal deposit.
The results of the U/Pb age dating show that the granitoid has an age of 161.6 MYA (+/- 1.2 MYA). This is identical in age to the Galena Bay Stock that is located 20km to the west of Thor. If this boulder field of intrusive rocks is derived from an intrusive body at Thor, it means that the intrusive is older than the Max Mine.These latter “Jurassic” porphyry deposits are relatively common in British Columbia, and these are generally of the calc-alkaline Cu +/- Mo +/- Au variety. The widespread occurrence of gold in the Thor epithermal deposit, and elevated copper content within the defined vein systems suggests that Thor could be connected at depth to a concealed Cu-Au type intrusive body.
Based on (Ce/Nd)/Y vs 10,000*(Eu/Eu*)/Y and (Ce/Nd)/Y vs. Dy/Yb diagrams, the zircons from the granitoid formed in an oxidized magma which fall in the “Ore Forming/Prospective” field. The magma that formed the granitoid is characterized by a high H2O content and high oxidation state that is required to form both porphyry and epithermal deposits