Geological mapping and sampling in the Windy Gulch Segment of the Dawson Project led to the realization that all the rocks hosting the gold mineralization could be better characterized as aluminum-rich (peraluminous) intrusions that not only host the gold but were also the direct sources of the gold mineralization (Keith et al., 2016). As such, the peraluminous intrusions comprise a portion of a staged intrusive sequence. Each stage is associated with a specific magmato-hydrothermal greisen-like hydrothermalite rock that is variously biased for a specific metal suite ranging from copper dominated to gold dominated. When compared to the literature, the gold deposits at Dawson can be broadly described as “intrusion related gold deposits” as in the recent summary of the problem by Pertzel (2013), which is a reconstitution of the phenomena as anticipated by Spurr (1906). The development of the peraluminous portion of the model was discussed by Keith and Swan (1985), Swan and Keith (1986) and at a symposium on the subject chaired by MagmaChem in Denver (Swan and Keith, 1987).

Gold and base metal mineralization occur within an east-northeast trending, south-southwest-dipping fault in amphibolite-grade, Proterozoic-age metamorphic rocks. Strike-length of the entire mapped horizon is about 3.4 mi, of which about the eastern 1.6 mi, which is gold prospective, occurs within the Property.

East of the Windy Point Segment, mineralization is dominated by iron and copp ........

Several mining methods could be applied to this deposit, including “Alimak mining,” shrinkage stoping, and longhole sublevel stoping. The various advantages and disadvantages of each method were considered and longhole sublevel stoping was selected for preliminary mine design.

For the Dawson deposit, the portal will be at elevation 6,500 ft. The base of the known mineralization is at about 5,400 ft, a vertical distance of 1,100 ft.

The terrain at Windy Gulch is steep and small, crawler-type drills are proposed. Excavation could be carried out using a relatively small excavator (25 to 45 ton). Articulated, six-wheel-drive haul trucks (20 to 35 ton) are appropriate for the steep, rough terrain. Any pit haul roads that are needed would be kept outside the cut as much as possible.

The small open pit could be profitable, however, with the assumptions made and the required infrastructure necessary to excavate the pit, the economic value does not justify including the Windy Gulch indicated and inferred resources in the economic assessment.

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