The Brian Boru occurrence is located on the west side of the Rocher Deboule Range, 18 kilometres south of New Hazelton.

The property is underlain by clastic sedimentary rocks (interbedded sandstones and argillites) of the Lower Cretaceous Red Rose Formation (Skeena Group) which are overlain by volcanic rocks of the Upper Cretaceous Brian Boru Formation of the Kasalka Group. The sedimentary rocks strike north and dip 35 degrees east.

The property consists of several showings comprising veins, up to 30 centimetres in width, containing black sphalerite, galena, pyrite pyrrhotite and chalcopyrite in a gangue of quartz. The veins are all near the contact between the Red Rose Formation and the Brian Boru Formation. They generally strike northeast, dipping to the northwest. A 15-centimetre channel sample taken from one vein assayed trace gold, 220.5 grams per tonne silver, 1.84 per cent lead, and 11.27 per cent zinc (Geological Survey of Canada Memoir 223).

In addition to the showings on the main Brian Boru property, Assessment Report 14632 refers to two other mineralized areas. These are the Jones and South Oxidation showings between the Brian Boru area and the Killarney area (093M 114). The precise location of the Jones and South Oxidation showings is not known.

Work History

In 1925, some work of an unknown nature was done on the Brian Boru by J. Creagh. In 1926, Creagh and Dunbar worked on the Brian Boru on nine claims and two Crown grants. Exploration work was done in open cuts and short adits. Little work was done after the 1920s. In 1927, J. Creagh continued work on the Brian Boru occurrence.

In 1979, Noranda collected four rock samples from the Brian Boru occurrence (Property File).

In 1980, 1981, 1984, Asarco Exploration established a grid on the Brian Boru/Killarney occurrence areas 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 prospected for new targets on the Brian Boru/Killarney. Mapping was completed on the Brunswick (093M 066), Balsam, No. 4(?) (093M 059?), Kaslo and Betty veins (093M 066) (Assessment Report 16012).

In 2007, Crucible Resources Ltd. collected four stream, two chip, one float and four talus samples at the Armagosa (093M 068); five stream silt samples in the Brian Boru area and one stream and five float samples were in Porphyry West area.

In 2008, Duncastle Gold Corp. collected 51 rock and 53 silt samples in the Brunswick, Jupiter (093M 065), Armagosa and Brian Boru areas (Assessment Report 30431). One aspect of the work in 2008 consisted of fieldwork in the northern branch of the Brian Boru Creek drainage, where the only old mine workings explored were at the Brian Boru adit. Numerous rock samples were collected. The ridge rising on the south of the creek appeared to host a number of small adits (on both sides of the ridge), in addition to the main adit. The most notable samples collected were sample 23201, which was a massive sulphide boulder dominantly comprised of sphalerite and pyrrhotite, and sample 23176, which was highly limonitic, but otherwise similarly massive sphalerite and pyrrhotite. Samples 23201 and 23176 assayed 0.10 and 1.11 grams per tonne gold, 152.0 and 66.0 grams per tonne silver, 0.50 and 0.13 per cent copper, 14.26 and 22.27 per cent zinc with 0.013 and 0.019 per cent cobalt, respectively (Assessment Report 30431).

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

The Porphyry Creek project consists of 13 mineral claims covering an area of 4811 hectares (ca. 2017). The claims overlap a small group of Crown-granted claims that surround the past-producing Red Rose tungsten mine (093M 067) and it is assumed that this area is fully excluded from the property.

The Porphyry Creek property contains eight separate MINFILE occurrences listed as: Armagosa (093M 068), Balsam (093M 059), Big Thing (093M 062), Brian Boru (093M 064), Brunswick (093M 066), Jupiter (093M 065), Sultana (093M 061), and Tina (093M 060). The Brunswick mine had some minor production from two adits driven to 20 and 52 metres, respectively and possibly from open cuts, prior to 1950. Development occurred mainly in the 1920s, and the total amount of ore produced is unknown, but ‘thirty bags’ of handpicked ore are reported from a later operator in 1954. Other occurrences that are reported to have some old development workings include the Armagosa and the Brian Boru, consisting of small open cuts and short adits. The Sultana prospect has had more extensive past exploration, including substantial trenching (essentially small-scale mining) and limited drilling on a high grade silver vein. This prospect was the main focus of an exploration and drilling program in 2010 and 2011 that identified extensive low grade copper and molybdenum mineralization below and to the northwest of the historical workings.

In 2018, Lansdown Holdings completed a minor program of prospecting and soil and rock sampling on the area.

Refer to Sultana (093M 061) for further details of the Porphyry Creek property work history, of which the Brian Boru was part of.