The Julie occurrence is located on the west side of the Coldwater River, approximately five kilometres north of the Coquihalla Lakes. Base and precious metal mineralization were originally discovered at the Keystone mine (092HNW024), located about one kilometre to the north, in the early 1900's with underground development having taken place by 1936.
The geology of the upper Coldwater River area is characterized by Late Triassic Nicola Group metavolcanic and metasedimentary rocks derived through the emplacement of plutonic rocks assigned to the Late Jurassic and Early Cretaceous Eagle Plutonic Complex to the west. Along the Coldwater River, the Nicola Group comprises amphibolite, foliated diorite, mylonite and chlorite schist with minor marble in contact with gneissic granodiorite. A dioritic stock of Early Tertiary age has intruded these plutonic rocks west of this contact.
The Julie zone is situated adjacent to the southwestern contact of the quartz diorite (Keystone) stock. The southern half of the stock is brecciated, as is the Eagle Plutonic Complex granodiorite adjacent to it. The brecciation has been attributed to the emplacement of relatively small stocks and dykes of porphyritic rhyolite. This event was apparently accompanied by pervasive alteration and the introduction of metallic mineralization. It is within one of these brecciated rhyolite porphyry stocks that the Julie zone is located.
The stock is elliptically shaped, with long and short axes measuring 150 and 80 metres, respectively. The pipe-like structure and the surrounding granodiorite are brecciated and hydrothermally altered.
Mineralization occurs along fine fractures, in quartz-carbonate stockwork veins and as lenses within both the rhyolite and the granodiorite. Pyrite and specular hematite with lesser sphalerite are the most common metallic minerals present, frequently occurring with rhodochrosite and thin quartz veinlets. Galena, magnetite and chalcopyrite have been observed, but are rare.
To the north of the Julie occurrence, on the south bank of Dry Creek, another zone of mineralization, referred to as the Stenvold workings, is reported and comprises fine-grained, crystalline pyrite with minor sphalerite, chalcopyrite, specularite, tetrahedrite and galena is disseminated in an altered intrusive breccia. By 1954, this zone is reported to have been explored by a tunnel, extending approximately 90 metres south from Dry Creek with 15-metre crosscuts at 69 and 76.5 metres down the tunnel.
In 1954, a sample from a 5-centimetre wide vein, exposed at surface near the Stenvold workings, yielded 1984 grams per tonne silver (Property File - 650178).
In 1966, drilling and trenching is reported to have traced the Julie occurrence over an area 24 metres wide, 60 metres long and 24 metres deep containing approximately 96 765 tonnes estimated to average 0.1 per cent copper, 0.6 per cent zinc and 8.5 grams per tonne silver (Assessment Report 7135). Ten of the drillholes are reported to have yielded an average of 1.74 per cent zinc, 0.12 per cent copper and 12.7 grams per tonne silver over an average of 21 metres (Assessment Report 28410).
In 1973, a drillhole (NC-3-73), located approximately 800 metres east-northeast of the Julie occurrence, yielded 0.44 per cent zinc over 15 metres of brecciated quartz monzonite with pervasive clay-sericite and disseminated pyrite (Assessment Report 7135).
In 1978, two rock samples (K17-2 and -3) from the Julie occurrence yielded up to 0.133 per cent lead, 0.310 per cent zinc and 17.6 grams per tonne silver (Assessment Report 7135).
The best core sample from several holes drilled in 1981 to test the Julie zone assayed 8.57 grams per tonne gold across 6.1 metres (Assessment Report 19139).
In 1989, drilling yielded intercepts including 0.068 per cent copper, 0.308 per cent lead, 0.494 per cent zinc, 313.4 grams per tonne silver and 0.12 gram per tonne gold over 3.0 metres (41.5 to 44.5 metres down hole) in hole 89-J3 and 0.278 per cent zinc with 16.5 grams per tonne silver over 37.0 metres, including 0.029 per cent molybdenum, 0.101 per cent copper, 0.099 per cent lead, 0.401 per cent zinc and 102.3 grams per tonne silver over 1.0 metre in hole 89-J1 (70.5 to 107.5 metres down hole) (Assessment Report 19139).
In 2005, 1.0- by 0.5-metre chip samples (5109 and 5110) yielded up to 0.049 per cent molybdenum, 0.266 per cent copper, 34.92 per cent zinc, greater than 0.200 per cent cadmium and greater than 100 grams per tonne silver (Assessment Report 28410).
Work History
The area has been explored in conjunction with the nearby Keystone (MINFILE 092HNW024) occurrence and a complete exploration history of the area can be found there.
In 1965 and 1966, Dorian Mines is reported to have completed approximately 1500 metres of trenching and 32 diamond drill holes, totalling 2018 metres, on the area south of Dry (Mine) Creek (MINFILE 092HNW023 and 092HNW022).
