The JW prospect is a porphyry Cu-Au target located within 6 km of the >800 million tonne Galore Creek porphyry deposit(s). The host rocks are predominantly a multiphase Late Triassic (?) intrusion dominated by granodiorite with lesser leucogranite, monzonite and dioritic phases, as well as the flanking metasediments and lesser volcanics. Mineralization occurs in both the intrusion and the adjacent metasediments/metavolcanics as both disseminated and veinlet chalcopyrite plus secondary copper minerals. Mapping to date has identified zones of strong epidote (propylitic) alteration, a pyrite zone, and boulders of magnetite-veined, potassic-altered granitic rocks, all typical phases of porphyry-type alteration systems.
The overburden covered terrain is locally steep across the core of the pluton and will require a properly equipped team of geologists to complete the mapping and prospecting and assist a geophysical crew in completing an IP survey across this key area.
Past exploration was carried out on the JW property from 1959 to 1990. Kennco explored porphyry copper mineralization from 1959 to 1965, reporting a trench with 13.1 metres grading 0.76% Cu. Bellex and Sarabat explored the property from 1988 to 1990; Bellex concentrated on the porphyry potential of its southern portion and Sarabat explored the Au-rich veins peripheral to the porphyry system on its northern portion. Sarabat identified a number of narrow, E-W trending quartz-sulphide veins, including Jake’s Vein (170 m strike length averaging 25.3 g/t Au across 0.23 m) and the Boundary Vein (11.3 g/t Au across 3.4 m). Bellex identified a strong coincident Cu-Au soil anomaly measuring 500 x 1,400 metres and drilled five holes on its fringes. Each of the holes intersected Cu-Au mineralization, including 51 metres @ 0.24% Cu and 0.48 g/t Au (JW90-01) and 45 metres @ 0.24% Cu and 0.36 g/t Au (JW90-03).
Romios’ exploration on the JW property in 2007 consisted of an airborne geophysical survey and 481.5 metres of diamond drilling in three holes on the North Fork porphyry prospect. Due to scheduling problems and conflicts with mountain goat kidding season, the airborne survey was not completed until after the 2007 drilling program. The airborne magnetics outlined a NNE-trending magnetic high 2.4 km long that widens from ~200 m in the south to ~1,100 m in the north. This magnetic high appears to correlate with magnetic phases of the predominantly granodiorite pluton.
A total of 3 holes totalling 481.5 metres were cored with BTW tools in the North Fork prospect by Romios in 2007. These holes were designed to test the Boundary Zone Vein and the heart of the Cu-Au soil geochemical anomaly, as defined by >200 ppb Au and >500 ppm Cu to the north and northwest of the historic 1990 drilling. The aeromagnetic map would now suggest these holes were outside the main pluton. However, drill hole JW07-06 intercepted 2.4 metres with a weighted average of 31.9 g/t Au (true width of 1.8m) from 279.8 m to 282.2 m. This hole also intersected a broad low-grade section (27.4 m of 0.23 g/t Au and 0.17% Cu) contained within the inter-fingered contact between the andesite volcanics and the granodiorite intrusive.
Hole JW07-07 was designed to test under the main part of the Au-Cu soil anomaly, but failed to intercept any significant alteration or mineralization. Hole JW07-08 tested the centre of the broadest portion of the anomalous gold and copper soil anomaly but it was abandoned at 32.5 metres without reaching bedrock. Given the thickness of the overburden in this area, Romios’ geologist concluded that the soil anomaly was not reflective of a nearby underlying bedrock source but was likely transported some distance.
The 2018 program was a brief mapping and sampling exercise intended to familiarise the new Romios geological team with the geology of the JW claim. This program led to the discovery of a previously undescribed pyritic alteration zone along the western margin of the pluton with local gold values up to 1.9 g/t Au and up to 574 ppm Cobalt, as well as extensive epidote alteration, magnetite-veined, potassic altered granitic boulders, and locally prominent secondary coper staining in the metasediments/volcanics flanking the western margin of the pluton.
In addition to the goal of expanding the extent of mapping of the lithologies, the 2019 exploration program was focussed on further delineation and sampling of the various types of mineralization and alteration styles present on the JW claim. A suite of intrusive phases ranging from white alaskite/granites to granodiorite was located along the western margin of the pluton, all of which contain local, fine-grained disseminated copper mineralization (chalcopyrite and malachite) and numerous samples assayed up to 1.43% Cu plus 0.1 g/t Au to 0.4 g/t Au. Several narrow quart-carbonate veins assayed from 1.3 g/t Au to 10.7 g/t Au. A very strong, pervasive propylitic (epidote) alteration zone was located along the NW margin of the pluton north of the pyritic zone discovered in 2018.
A wide range of rock samples was also collected for alteration mineralogy characterization by a hyperspectral analysis conducted on Romios’ behalf by Mr. John Ryan of H.E.G. and Associates. The results of this initial hyperspectral analysis was supportive of a porphyry type alteration pattern although further sampling is required in the central core of the pluton to confirm the shape of this alteration pattern.
Based on the results of the most recent mapping and past drill programs, there seems little doubt that a porphyry-copper type alteration-mineralization system is present on the JW claim. Its extent may be reflected in part by the dimensions of the aeromagnetic high, the main northern lobe of which is ~1 km x 1.3 km in area.
In spite of the proximity of this pluton to Galore Creek, no obviously alkalic phases have been found as yet and all of the mapped intrusive phases - diorite-granodiorite-monzonite-leucogranite - may be part of the calc-alkaline Texas Creek plutonic suite. These intrusions are related to significant mesothermal and epithermal precious and base metal deposits at the former Premier, Johnny Mountain and Snip mines, and at Kerr-Sulphurets.
The JW prospect is considered a high-priority porphyry Cu-Au target located within 6 km of the >800 million tonne Galore Creek porphyry deposit(s). The association of high-grade gold veins around the periphery of the porphyry warrants the expansion of future exploration efforts at JW from solely a porphyry Cu-Au focus to one that includes vein deposits as well.