Summary:
The Project is primarily underlain by Neoproterozoic to Silurian clastic sedimentary rocks of the Selwyn Basin and clastic sedimentary rocks and chert of the Ordovician to Silurian Road River and Earn groups. Due to the vast size of the Rogue Project, the description of property geology will be discussed as four regions – eastern (hangingwall of the Arrowhead thrust fault), northern (footwall of the Arrowhead thrust fault), western and southern parts of the Project.
The Arrowhead thrust and complex dextral strike slip fault systems essentially bisect the Project area. The geology on either side of this structural break shows substantial differences in both stratigraphy and structural character.
The eastern region (footwall of the Arrowhead thrust fault or hangingwall of the Elmer Creek thrust) is underlain by strata of the Arrowhead Member of the Narchilla Formation, Marmot assemblage, Gull Lake Formation and the overlying Road River and Earn groups, found within a series of folds. Cecile (1998) referred to the folded strata as the “Emerald Lake synclinorium,” characterized by northeast-trending folds cored by rocks of the Earn Group. Tight folding is developed parallel to the fold axis of the Emerald Lake synclinorium with northeast and southwest trending fold axes. Several intrusions of the Tombstone and Mayo suites are found cutting across the folded rocks forming both larger bodies (e.g., Emerald Lake and Rogue plutons and the West Rogue stock) and smaller stocks, plugs and dykes.
The northern region (hangingwall of the Arrowhead thrust fault) is primarily underlain by the Arrowhead Member of the Narchilla Formation. Clastic sedimentary and minor volcanic rocks of the Gull Lake, Marmot and Steel formations are found as isolated exposures, overlying the Narchilla Formation. A small, rounded pluton of the Mayo suite (Old Cabin pluton) intrudes this package. Minor siliclastic and carbonate rocks of the Algae and Blueflower formations are found in the hangingwall of a small thrust in the northernmost Project area.
The western region comprises a complex juxtaposition of fault bound blocks of Hyland, Road River and Earn groups and Marmot, Gull Lake and Blueflower formations. Thrust, normal and strike-slip faults within this area crosscut one another. The Survey stock, a pluton of the Mayo suite, intrudes across some of these structures in the area of the Fango Minfile occurrence.
The southern region comprises a tail of quartz claims that follows the Plata Winter Trail. These claims cross a south dipping thrust fault that places rocks of the Narchilla and Gull Lake formations over Road River and Earn group rocks. In the hangingwall of the thrust, an east-west trending strike-slip fault juxtaposes the Narchilla and Gull Lake formations against the Mount Christie Formation chert, shale and minor quartzite and limestone. The Mount Christie Formation, in turn, is structurally overlain by Road River and Hyland group rocks.
Multiple intrusive bodies assigned to the mid-Cretaceous Mayo and Tombstone plutonic suites are found on the Project within and near the apex of the regional drag fold related to dextral movement along the Hess-Macmillan fault system. Collectively, Snowline refers to these intrusive bodies as the “Rogue Plutonic Complex.” Many of the named plutons are surrounded by conspicuous magnetic thermal aureoles that can be observed in regional geophysical surveys. Most of these intrusions have not been dated but have been allocated to certain plutonic suites based on composition and geochemical character (Hart et al., 2004).
Deposit Types
While most mineralization observed to date on the Rogue Project is likely attributable to the Rogue Plutonic Complex and thus would be reduced intrusion-related in nature, the Rogue Project and its surroundings are prospective for both Carlin-style and orogenic Au mineralization as well. These deposit models should be considered when evaluating results and generating new exploration targets on the Rogue Project. The following characteristics are not necessarily indicative of Rogue Project mineralization.