The Porphyry Creek occurrence is located along Porphyry Creek, 1200 metres north of the confluence with Kliyul Creek, approximately 110 kilometres north-northwest of the community of Germansen Landing.
The occurrence is near the northern end of the Early Jurassic to Early Cretaceous Hogem Plutonic Suite. The property covers a volcanosedimentary assemblage of Upper Triassic Takla Group rocks (Plughat Mountain Formation), which have been intruded by a Jurassic or older mafic-ultramafic stock of the Late Triassic to Early Jurassic Aiken Lake Intrusive Complex and calcalkaline intrusions of the Hogem Plutonic Suite. The property encompasses previously known areas of copper, gold, and molybdenum mineralization on map sheets 094C05W and 094D08E (see Croydon (094C 008), Bloom Cirque (094C 039), Porphyry Creek Molybdenum (094C 065), Sarah (094C 075), and Davie Creek Moly (094D 113).
The Takla Group is comprised of mafic to intermediate flows, pyroclastics and lesser calcareous argillite and limestone. Intrusive bodies include minor pyroxenite, diorite, quartz diorite, granodiorite, and quartz monzonite. Dike compositions include monzonite and rare syenite.
Alteration present in Takla rocks consists of ubiquitous chloritization, local epidotization, biotitization, silicification, recrystallization, partial to total replacement of pyroxene by amphibole, carbonate alteration along faults and shears, and broad hornfelsing. Alteration minerals within intrusive rocks include epidote, saussurite, magnetite, pyrite, potassium feldspar, sericite, quartz, and carbonate.
Widespread copper mineralization is evident throughout the property and comprises chalcopyrite, with or without malachite, azurite, and rare chalcocite or bornite, and occurs as disseminations, as fracture fillings and in shears. Specks of native gold were found in three (quartz)-carbonate veins, with or without copper, and in pan concentrates from Porphyry Creek. Galena, with or without sphalerite, occurs locally in quartz-carbonate veins. Molybdenite is found in quartz-carbonate-(plus/minus) potassium feldspar veins and stringers, west of Croydon Creek. Hematite is common along fractures and in veins on the west half of the property. Highly significant concentrations of gold and base metals are associated with late-stage intrusive activity.
From recent exploration work, it is apparent that at least two complex mineralizing systems are present on the Porphyry Creek property. The first system occurs on map sheet 094D08E, where in 1964 Rio Tinto recognized the "Davie Creek stock" as part of a porphyry molybdenum system (see Kliyul, 094D 113). In 1978, Teck Exploration Limited explored the area, held under the Kliyul claims, with a grid soil geochemistry survey and two diamond-drill holes (497.7 metres).
The mineralized Davie Creek stock occurs 900 metres north-northwest of the original Porphyry Creek showing which is on adjoining map sheet 094C05W. Roughly 100,000,000 tonnes grading 0.1 per cent MoS2 was outlined in the Davie Creek stock (Assessment Report 21521, Volume 1, page 14). Mineralization is within a tabular (750 by 260 metres), potassically zoned granodiorite intrusion. A weak copper halo, locally coincident with weak tungsten, exists peripheral to the main zone. A broad, strongly gossanous, hornfelsed zone is peripheral to the Davie Creek deposit and extends southeastward along Porphyry Ridge. An examination of the 1982 diamond-drill core from the Davie Creek stock found features previously unrecognized. The Davie Creek stock, and/or alteration and mineralization within the stock, is genetically related to late-stage intrusive activity. The presence of large screens, xenoliths and previously unrecognized intrusive breccia zones indicate potential for copper and gold mineralization peripheral to the stock and defines the second mineralizing system on the Porphyry Creek property.
Old opencuts and a 3-metre-long adit on map sheet 094C05W (the original Porphyry Creek occurrence; Geological Survey of Canada Memoir 274, page 212) exposes a mineralized area consisting of narrow veins and disseminated pyrite, chalcopyrite and molybdenite associated with large masses of white quartz in medium-grained, dark green hornblende diorite. Quartz is exposed at intervals for a length of 60 metres and a width of 18 metres. Lenticular veins of pyrite and molybdenite are up to 10 centimetres wide. Stringers of chalcopyrite up to 1.25 centimetres wide cut both the quartz and the hornblende diorite.
In the mid-1930s, the Consolidated and Smelting Company of Canada Limited discovered copper and gold-bearing quartz veins in the area of Porphyry and Croydon creeks, tributaries of Kliyul Creek. By 1938, several open cuts and about 400 metres of drift and crosscuts had been completed on the showings. During the same year, the mine camp and facilities were destroyed by a bush fire and all work was abandoned.
In 1947, Springer-Sturgeon Gold Mines Limited undertook prospecting in the area and staked the Shell group of claims (094D 015) at the headwaters of Porphyry Creek.
During the 1950s, the old Croydon property (094C 008) was restaked as the Jane Group and in 1958 was explored by Noranda-Canex-Bralorne. The partners completed 468 metres of diamond drilling and some geological mapping.
