The Armagosa occurrence is located on the western flank of Rocher Deboule Mountain about 10 kilometres south of the town of South Hazelton.
The hostrocks are hornfelsed greywacke and argillite of the Middle Jurassic to Lower Cretaceous Bowser Lake Group. These are intruded by the Rocher Deboule stock, a Late Cretaceous porphyritic granodiorite body which is part of the Bulkley Plutonic Suite. Bedding in the sedimentary rocks strikes 330 degrees, dipping 30 degrees northeast.
The property hosts several narrow, northeast striking, steeply southeast dipping fracture zones, some of which are vein-filled, containing chalcopyrite and magnetite. The showings have been explored by two adits and a short shaft. Northwest of the main showings, towards the Great Ohio property (093M 069), are several small veins carrying scheelite. These veins strike 030 degrees, dipping 60 degrees west and are generally less than 30 centimetres thick.
The Armagosa property was originally part of the Great Ohio group, but has been relocated many times since. At one stage it was called the Spaulding group. Assessment work was reported on the Armagosa group in 1912 and 1916. The old workings include two adits and one small shaft. The lower adit at elevation 1323 metres is of unknown length; the upper adit at elevation 1408 metres is 46 metres long. Skeena Silver Mines Ltd. prospected the showings in 1952.
In 1973, the Brunswick (093M 066) was optioned to Arcadia Explorations. Underground to surface transit surveying and a topographic plan was completed. Geological mapping of showing and seven grab samples were collected. An electromagnetic survey line was completed over the adit vein and a self-potential survey on five cross-lines was completed. A bulldozer excavated Trench 1 and Trench 2.
In 1983, the Rocher Deboule property (Victoria Group) was owned by the D. Groot Logging Ltd. and it appears that the Armagosa was part of that group. Some minor descriptions are made.
In 1987, Southern Gold mapped and prospected the Armagosa showing, collecting nine rock grab and 38 soil/talus samples. Some geophysical surveying was completed (Assessment Report 16714).
During 2001 through 2007, Rocher Deboule Minerals Corporation completed programs of rock and soil sampling, prospecting, geological mapping and an airborne (electromagnetic, magnetic and radiometric) geophysical survey on the area as the Rocher Deboule property.
In 2007, Crucible Resouces Ltd. completed an option on the Brunswick and Jupiter (093M 065) from D. Warkentin. Some sampling was done in the Armagosa area.
In 2008, Duncastle Gold Corp. collected 51 rock and 53 silt samples in the Brunswick, Jupiter, Armagosa and Brian Boru (093M 064) areas (Assessment Report 30431). Several of the rock samples collected were from the dumps of historical workings. Historical records are limited so this provided some confirmation of the mineralization from these locations. At the Armagosa, no significant values were found, but at the Brunswick mine and Brian Boru prospect adit some very high grade mineralization was encountered.
In 2010, Dunham Gold Corp. completed a 495 kilometre airborne geophysical survey on its Porphyry Creek property which covered numerous showings including the Tina showing (093M 060) and area (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.
Refer to Sultana (093M 061) for further details of the Porphyry Creek property work.