The area around the headwaters of Azure River has claimed attention for several years due to the discovery of large bodies of auriferous quartz in metasedimentary rocks of the Shuswap Metamorphic Complex. Mineralization on the Blue Ice claim group is located at the headwaters of Hobson (Fred Wells) Creek.
The Blue Ice claim group lies near the contact between the Hadrynian upper Kaza Group and the stratigraphically overlying Isaac Formation of the Hadrynian Cariboo Group. The ground covering the Blue Ice claim group mineralization is on the crest and northeast limb of a major anticline which plunges at a low angle to the northwest. The country rocks, striking 255 degrees, consist of massive quartzite, quartz pebble conglomerate, quartz-sericite schist, phyllite, argillite and limestone, of the Isaac Formation. Lithologies of the Hadrynian upper Kaza Group consist of quartzofeldspathic psammite, phyllite, slate and minor grit.
Mineral occurrences at the head of Hobson Creek are found in zones of fracturing, crosscutting host rocks at an oblique angle. Lenticular quartz bodies consisting of white quartz host pyrite, galena and chalcopyrite, sphalerite and arsenopyrite, at points where these bodies intersect cross fracturing striking 300 degrees. Quartz veins hosted in fractures are also mineralized. Most are narrow, irregular stockworks or sets of short quartz-filled cracks and tension gashes approximately perpendicular to bedding. Siderite is a common accessory in quartz veins. Mineralization locally extends into interbedded limestone bands, forming massive sulphide replacement.
The East Zone is located under the southern flank of the foot of a glacier occupying the divide between Hobson Creek and the pass at the head of the Azure River. Here, a zone 76 metres wide, intersected by cross fractures and the development of a number of quartz bodies, aggregating 61 to 91 metres long by 7.3 metres wide.
Erratic mineralization consists of pyrite, galena, sphalerite and chalcopyrite and is found in three different orientations of quartz fissures but most commonly 010 to 020 degrees. Mineralization, predominantly pyrite, is semi-massive in some veins over widths of 5 to 60 centimetres and lengths up to 6 metres. Of six samples taken from this area in 1938, one of quartz with 60 per cent pyrite assayed 22.6 grams per tonne gold and 154.3 grams per tonne silver (Minister of Mines Annual Report 1938). Combined assay results from two samples taken in 1929 were 13.7 grams per tonne gold, 212.6 grams per tonne silver, 7 per cent lead and 10 per cent zinc (Minister of Mines Annual Report 1929).
Also at this showing, a continuous exposure of limestone, 267 metres long, is heavily mineralized with primarily pyrite forming a replacement body 33.5 metres long by 5.79 metres wide. Replacement mineralization seems definitely related to small pyrite-carbonate- bearing bodies in cross fissures in quartzite. In the main replacement body, sulphides occur in carbonate gangue, partially composed of siderite. The margins of this replacement body are definite. Pyrite comprises 50 to 90 per cent of the mass, varying in coarseness from a fine sugary texture to cubes 2.5 centimetres or more across. A sample was channel sampled across 5.5 metres (18 feet) near the center of the body from the hanging wall. Results are as follows with values expressed in grams per tonne (Minister of Mines Annual Report 1938).
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SAMPLE WIDTH LOCATION Au Ag
1 5 feet NE wall; nearly 25.37 10.28
solid pyrite
2 next 75 per cent 5.48 trace
5 feet pyrite
3 next 75 per cent 8.23 20.57
4 next within 8 inches trace 6.86
3 feet of footwall
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In addition to quartz veins, there is strong evidence of a replacement body beneath the ice in the presence of considerable float in moraine to the northwest of the glacial stream discharge.
Please refer to 083D 003 (Blue Ice (SE zone)) for more information.
