The Killarney showing is located on the west side of the south branch of Brian Boru Creek, on the west side of the Rocher Deboule Range, 19 kilometres south of South Hazelton.

The showings are hosted in fractured and bleached acid pyroclastics of the Upper Cretaceous Brian Boru Formation (Kasalka Group). Potassium/argon dating of biotite yielded a date of 70 million years (Geological Survey of Canada Open File 2322). An important north-striking block fault, the Cap Fault, separates the volcanic rocks from clastic sedimentary rocks (sandstones and argillites) of the Lower Cretaceous Red Rose Formation (Skeena Group).

At the showings, the bed of Brian Boru Creek is formed of fragments of altered rock heavily impregnated with pyrite and a little pyrrhotite, sphalerite and galena. A heavily pyritized zone, approximately 3 metres in width, outcrops in an open cut some tens of metres west of the creek. Some tens of metres south of a clearing an adit has been driven along a zone containing pyrite, sphalerite and galena. This zone occurs along the margins of an aplite dike which has intruded tuffaceous host rocks. The average of several samples taken from mineralization in the area was 19.9 grams per tonne silver, 1.04 per cent zinc, 0.19 per cent lead, 0.01 per cent copper, 0.11 per cent tin, and trace gold (Assessment Report 13340).

In 1926, J. Creagh discovered the Killarney showing. Open-cuts over several hundred feet and one adit (of unknown length, located on the south fork of Brian Boru Creek

In 1980, 1981, 1984, Asarco Exploration established a grid on the Brian Boru/Killarney occurrence area and collected 156 soil samples. Later, mapping and 63 rock and 15 soil samples were collected. In 1985, Asarco, mapped and prospected the Killarney Grid, collecting 74 rock and talus samples; an extension of the soil survey grid was made and 341 samples were collected; silt sampling of creeks resulted in 17 samples.

In 1987, Catoosea Resources relocated old workings and prospect for new targets on the Brian Boru/Killarney. Mapping was completed on the Brunswick, Balsam, No. 4(?), Kaslo and Betty veins (Assessment Report 16012).

In 2008, Duncastle Gold Corp collected 2 rock samples, 5 stream sediment samples and 3 soil samples on the Killarney which part of their Porphyry Creek property (Assessment Report 30096).

In 2010, Dunham Gold Corp completed a 495 kilometre airborne geophysical survey on its Porphyry Creek property which covered numerous showings including the Killarney showing and area (Assessment Report 31728).

Refer to Sultana (093M 061) for further details of the Porphyry Creek property work history.