The oldest rocks in the Hemlo West 15 region consist of a thick sequence of weakly metamorphosed siltstones and argillites of the Devonian to Permian Stikine Assemblage. Overlying this sequence are black shales, siltstones, greywacke and conglomerate of the Upper Triassic Stuhini Group. Intruding the stratigraphyesozoic rocks are various plutonic rocks which range in composition and may be Mesozoic to Tertiary in age.

On the property, the dominant sedimentary rock type consists of black to grey, foliated and well-bedded argillaceous siltstone. The siltstone grades into well-indurated, poorly foliated and well-bedded quartz sandstone. Other sediments include massive chert and interbedded chert. The volcanics consist mainly of mafic volcanic tuffs and breccias with dark grey to green mafic volcanic flows which include feldspar porphyry volcanic flows.

Orthoclase porphyry occurs as a small stock centered in vicinity of the Hemlo West 15 claim and is part of the the Triassic-Jurassic Iskut River (Bronson) stock consisting of monzodiorite to gabbro. This area was largely covered by the Southwest grid of the Iskut Joint Venture, who worked the area in the 1980s and 1990s and who's Hemlo West claim group exists still in 2012. The intrusive is characterized by 1 to 3 centimetre long orthoclase phenocrysts in a medium to fine-grained plagioclase-pyroxene matrix. Alteration from this intrusion consists mainly of chloritization and some epidotization with intense quartz veining developed within and proximal to the intrusive.

Mineralization on the Hemlo West 15 claim consists of quartz veins and disseminated mineralization which appears to be related to the orthoclase porphyry intrusion. Associated with the porphry in- trusion is veined and disseminated pyrite with chalcopyrite and some malachite which is considered to be part of a pyrite halo surrounding the intrusion. In 1983, a sample of disseminated pyrite and chalcopyrite in siltstone assayed 0.02 grams per tonne gold, 4.2 grams per tonne silver and 0.07 per cent copper (Assessment Report 11320). In 1986, a sample from heavily epidotized and chloritized siltstone with 3.0 per cent disseminated pyrite assayed 0.05 grams per tonne gold (Assessment Report 15336).

In 1990, limited prospecting on the Southwest grid (which covers the Hemlo West 15 occurrence, did not uncover any economic mineralization. The only significant gold and copper results were reported to be from a 20 centimeter wide quartz vein hosted by orthoclase porphyry (Assessment Report 21041).

Field work in 1991 on the Southwest Grid covered a significant portion of the early Jurassic Bronson Stock and its western contact with Triassic volcanic and sedimentary rocks. 1987 soil geochem resulted in 7 Au-in-soil, 23 Au-in- soil (unknown copper), 7 Au & Cu-in-soil, 14 Cu-in-soil, 4 Au-in-silt (unknown copper), and 1 Au & Cu in silt anomalies. Discrete gold values ranged up to 560 ppb, but are generally less than 100 ppb, and display poor lateral continuity (Assessment Report 22089). . Copper values range up to 1000 ppm, and are not clearly correlated with gold content. The discrete gold-in-soil geochemical anomalies within the grid are situated near discontinuous, contact related quartz veins with anomalous and comparable, but inconsistent gold values. The veins, reportedly, not been properly trenched to fully expose their ultimate size potential, which was not considered to be extensive. The intrusive was reported to appear fresh, not exhibiting the alteration assemblage characteristic of a mineralized porphyry system.

Refer to Gregor (104B 357) for further geological information and a discussion of a common work history.