The Star of Emory 3 property lies within an ultrabasic complex between the southern tip of the Coast Plutonic Complex and the northern end of a belt of intrusions termed the Chelan batholith. The intrusive rocks within this belt are granites, granodiorites and quartz diorites of Jurassic age and younger. They form the core of an uplifted block of regionally metamorphosed upper Paleozoic rocks which trend north, and are bounded by the Fraser River fault system on the east and west by somewhat less metamorphosed Mesozoic rocks.
The ultramafic complex hosting the Giant Nickel mine (092HSW004) mineralized zones is composed of hypersthene diorite and quartz diorites, norites and ultrabasic rocks, termed the Pacific Nickel Complex, which intrudes schists and earlier intrusive rocks. The older, noritic rocks are found northwest and southwest of the ultramafic complex. Potassium-argon ages from the ultramafic complex range from about 120 to 95 million years. The older ages were obtained from the hornblende pyroxenite phase with late hornblende dikes having the youngest ages.
The ultramafic rocks of the Pacific Nickel Complex form an irregular stock-like mass about 3.0 kilometres across. The northeast half of the stock consists of barren pyroxenites and peridotites which contain little or no hornblende. The southwest half of the stock is a highly variable, hornblende-rich assemblage of peridotites which are mineralized and contain some seventeen orebodies associated with the Giant Nickel mine. These orebodies are scattered along a line trending about 285 degrees.
The Star of Emory and Brunswick orebodies lie along Emory Creek just west of the Pride of Emory and Discovery ore zones. The ore is associated with pipe-like concentrations of pyrrhotite, pentlandite and chalcopyrite which plunges between 65 to 70 degrees to the north- northeast. The ore is very massive and in places has over 60 per cent sulphides. Some of this concentration is due to the presence of chalcopyrite of replacement origin. The mineralized ultramafic bodies are cut off by diorite intrusions. The hostrock is described as mainly hornblende pyroxenite, hornblendite and minor peridotite hosting both disseminated and massive mineralization.
In 1975, drilling intersected massive mineralization comprised mainly of chalcopyrite, pyrrhotite and pentlandite with minor magnetite and rare chromite. In one hole, mineralization over 2.75 metres yielded 2.2 per cent nickel and 0.58 per cent copper. Another intersection over 0.9 metre yielded 4.69 per cent nickel and 0.28 per cent copper (Assessment Report 5385).
These orebodies are part of the Giant Nickel mine which was in operation from 1958 to 1974 inclusive. Nickel and copper were the prime metallic products with cobalt as a byproduct, however, chrome oxide, platinum, gold and silver were also reported. In 1987, prospecting revealed widespread nickeliferous mineralization. A total of 63 rock samples were collected and all were anomalous for chromium and three samples were anomalous for platinum. Gold and palladium values were also reported. Production is included with Pride of Emory (092HSW004).