The Irishman Creek occurrence lies 0.9 kilometre north of the Catface copper-molybdenum developed prospect (092F 120) and has been explored in conjunction with it and the Hecate Bay (092F 231) occurrence.

The area of the deposit is underlain by andesite and basalt flows, breccia and agglomerate in contact with diorite of the Mesozoic-Paleozoic Westcoast Complex. The age of the volcanics is in doubt and they are thought to belong to either the Upper Triassic Karmutsen Formation (Vancouver Group) or to the Paleozoic Sicker Group. Quartz monzonite of the Early to Middle Jurassic Island Intrusions, has intruded the contact area, followed by several quartz diorite to granodiorite phases of the Early to Middle Eocene Tofino Intrusive Suite (formerly Catface Intrusions), (Personal Communication, Nick Massey, May 1990).

Mineralization at Irishman's Creek consists of disseminated chalcopyrite, pyrite and some pyrrhotite in volcanic rocks and in brecciated quartz monzonite, near Tofino Intrusive Suite quartz diorite. A zone with greater that 0.2 percent copper mineralization measures 100 metres wide and 350 metres long (CIM Special Volume 15, page 308). The best drill intercept was 0.63 per cent copper over 155.4 metres, with silver up to 6.7 grams per tonne. A potential for 20 million tonnes of mineralized rock with unknown grade was estimated in 1970 (CIM Special Volume 46, pages 322-326). In 2010, diamond drilling (CF-10-58) intersected the breccia zone and yielded 0.797 per cent copper over 77.5 metres from 134.0 metres to 211.5 metres depth (Assessment Report 31894).

Also present are sulphide-rich masses containing magnetite, chalcopyrite, pyrite and pyrrhotite that occur over a width of one metre in or near a pyroxenite dyke that follows an east trending fault along Irishman's Creek.

In 1963 and 1964, Catface Copper Mines completed programs of soil sampling and a self-potential geophysical survey on the area. This work identified a strong geochemical anomaly in the Irishman Creek area (Assessment Report 540). In 1970, Fort Reliance Minerals completed a program of soil sampling and a ground magnetic survey. In 1999, Doublestar Resources Ltd. acquired the property from Falconbridge Limited. In 2005, Catface Copper Mines Ltd. and Doublestar had Eagle Mapping conduct a 1:20,000 aerial photographic and 2 metre contour topographic survey over their tenure, including the Irishman Creek prospect. In 2007, Doublestar was bought by Selkirk Metals Corp. In November 2009, Selkirk was bought by Imperial Metals Corporation. In 2010, Imperial completed a diamond drilling program of thirteen holes, totalling 3548.0 metres on the property. One hole, CF-10-58, was completed on the Irishman Creek zone.

Geological reconnaissance completed during the 2014 Catface field program successfully identified the presence of small-scale Eocene Catface intrusive dykes and stocks and Jurassic(?) monzogranite towards the north-northwest in the Lower Irishman Creek area. An approximately 5-metre-wide silicified porphyritic dacite dyke with weak laminated quartz veining and disseminated chalcopyrite-bornite(?) mineralization, located 150 m northwest of the Irishman Creek Zone hosted within monzogranite. Assay results from rock chip sampling of this dacite dyke returned a grade of 0.27 per cent Cu (ID.780973). Mineralized hydrothermal breccia, assigned to the Irishman Creek Zone, was located and sampled 50 m NW of the previously mapped surface expression, returning a grade of 0.48 per cent Cu (ID.780974).