The JD-Porphyry (JD East) occurrence is located at an elevation of approximately 1450 metres on an east-facing slope, west of McClair Creek and approximately 5.5 kilometres northeast of Kadah Lake.
The area is situated within a Mesozoic volcanic arc assemblage that lies along the eastern margin of the Intermontane Belt, a northwest-trending belt of Paleozoic to Neogene sediments, volcanics and intrusions bounded to the east by the Omineca Belt and to the west and southwest by the Sustut and Bowser basins.
Permian Asitka Group crystalline limestones are the oldest rocks exposed in the region. They are commonly in thrust contact with Upper Triassic Takla Group andesite flows and pyroclastic rocks. Takla volcanics have been intruded by the granodiorite to quartz monzonite Early Jurassic Black Lake Suite and are in turn unconformably overlain by or faulted against Lower Jurassic calc-alkaline volcanics of the Toodoggone Formation, Hazelton Group.
The dominant structures in the area are steeply dipping faults that define a prominent regional northwest structural fabric trending 140 to 170 degrees. In turn, high-angle, northeast-striking faults (approximately 060 degrees) appear to truncate and displace northwest-striking faults. Collectively these faults form a boundary for variably rotated and tilted blocks underlain by monoclinal strata.
Locally, diamond drilling has identified porphyry-style alteration, mineralization and veining over a strike length of 850 metres. Intensely phyllic- (quartz-sericite-pyrite) altered plagioclase porphyritic volcanic rocks with disseminated and vein-hosted pyrite and chalcopyrite mineralization. Below this early potassic alteration assemblages characterized by potassium feldspar and magnetite associated with quartz pyrite veins predominate as sharp vein halos. The parent augite-plagioclase porphryritic volcanic rocks are in contact with an altered feldspar porphyritic quartz monzonite intrusion. Zones of quartz stockworking mineralized with pyrite and chalcopyrite overprint the altered intrusion.
In 2013, diamond drilling yielded intercepts of 0.02 gram per tonne gold, 1.8 grams per tonne silver and 0.098 per cent copper over 37 metres, including 0.09 gram per tonne gold, 14.2 grams per tonne silver and 0.946 per cent copper over 3 metres and 0.467 per cent copper with 3.4 grams per tonne silver over the final 1.4 metres of hole JD-13-25 and 0.033 per cent copper over 321 metres in hole JD-13-28, located 500 metres south of the previous drillhole (Assessment Report 34762). Another drillhole (JD-13-26), located between the previous two holes, intercepted local zones of hydrothermal brecciation yielding up to 6.03 grams per tonne gold over 2 metres (Assessment Report 34762).
In 2018, two diamond drillholes (JD-18-001 and -002) were completed yielding short, 2- to 3-metre intervals of up to 0.447 gram per tonne gold and 0.091 per cent copper (Assessment Report 38203).
Work History
The area has been historically explored in conjunction with the nearby JD-Finn (MINFILE 094E 171) occurrence and a complete exploration history can be found there.
In 2012 and 2013, Tower Resources Ltd. completed programs of prospecting, geochemical (rock and soil) sampling, ground magnetic and induced polarization surveys, geological mapping and diamond drilling on the area as the JD property.
In 2015 and 2017, Freeport-McMoran Mineral Properties Canada Inc. completed programs of geological mapping, rock sampling and a 13.8 line-kilometre induced polarization survey on the JD property. In 2018, Freeport-McMoran completed a further program of geological mapping, rock sampling, a 42.8 line-kilometre induced polarization survey, a 671 line-kilometre airborne magnetic survey and two diamond drill holes, totalling 1294.1 metres, on the JD property.
