The jowett Volcanic/Intrusive Body
The Thor deposit overlies an intrusive/volcanic body, and the Thor deposit shows a close geometrical arrangement around that feature. This part of the deposit was recognized after completing geophysical modeling of the ground magnetic data, and has become an important exploration target.
Spatial Relationship to Zones at Thor - All of the lodes at Thor have a close spatial relationship to the Jowett volcanic/intrusive body. They are found on top of the body within the Thor Fault Zone.
The Jowett Formation is a regional rock unit that can be found on the flanks of the Silver Cup Anticline, and the Silver Cup Anticline has a close spatial relationship to most of the silver deposits in the Trout Lake area.
One of the mysteries at Thor is what lies between the existing Thor deposit and the Jowett porphyry/volcanic body, and also within the body itself. This is an exciting target that will be tested with drilling, and would dramatically increase the size of the deposit.
What does the Volcanic/Intrusive Body Look Like? - Despite all of the drilling completed at Thor, very few, if any of the drill holes have intersected the Jowett body.
This is because the Thor Deposit (as we know it) lies well-above the Jowett body. Recently, the Colorado School of Mines started a petrographic study of some of these rocks, and described some of the rocks peripheral to the intrusive body as hornfels, that also had minor amounts of pyrite and galena. Hornfels is a fine-grained contact metamorphic rock without obvious foliation, that has been altered by exposure to an intrusive body. Common temperatures for the formation of hornfels range from about 1300 to 1450 degrees F (700 to 800 degrees Celsius).
These rocks, that are exposed in Broadview Creek, are well below the existing deposit and exhibit many characteristics indicative of a large intrusive body located in close proximity. They also contain traces of iron sulfide and galena, and this is a particularly important since that suggests that the Jowett body itself is mineralized. Drilling this target takes deep, carefully planned exploration holes and Taranis has now labeled this as a high-priority exploration target. Many of the largest ore deposits in British Columbia are associated with porphyry/intrusive rocks.