The MBA Gold (Sam Northwest) occurrence is located at an elevation of approximately 1060 metres on a south-southeast–facing slope, northwest of Johnson Creek and approximately 3.5 kilometres west-southwest of the west end of Johnson Lake.
Regionally, the area is in structurally complex metasedimentary and metavolcanic rocks of the Paleozoic (Lower Cambrian and older(?) to Mississippian) Eagle Bay Assemblage. The assemblage has a complex deformational history involving multiple stages of thrust faulting and folding during the Jurassic-Cretaceous periods, which produced strongly foliated and overturned rocks trending northwest and dipping northeast. These Paleozoic rocks are intruded by mid-Cretaceous granodiorite and quartz monzonite (such as the Baldy Batholith), and Neogene quartz-feldspar porphyry, basalt, and lamprophyre dykes. These are all locally overlain by Miocene plateau lavas, now represented in the area by occasional erosional remnants.
The Eagle Bay Assemblage rocks include andesitic volcanic rocks of the Devonian to Mississippian Foghorn Mountain unit, greenstone and greenschists rocks of the Lower Cambrian Johnson Lake unit and Lower Cambrian mudstone, siltstone, shale, fine clastic rocks, limestone, and calcareous sedimentary rocks.
Locally, two zones (Sam Northwest and MBA Gold) and styles of mineralization have been identified by diamond drilling. The Sam Northwest zone comprises chert and argillite hosting quartz-carbonate veins with pyrite, sphalerite, minor galena, chalcopyrite, arsenopyrite, and trace tetrahedrite, similar to the that of the Rea Gold (MINFILE 082M 191) and Samatosum (MINFILE 082M 244) occurrences to the south east and are reported to relate to the Sam horizon of the Samatosum (MINFILE 082M 244) mine. The MBA Gold zone comprises zones of quartz carbonate (ankerite) veining with pyrite and coarse visible gold in the ‘Samatosum sedimentary unit’.
In 1990, drillhole RG-393 (grid coordinates 8+85N-121+00W) intercepted two mineralized horizons of brecciated chert and argillite hosting quartz carbonate veins with pyrite, sphalerite, minor galena and chalcopyrite, and trace tetrahedrite at 139.8 and 227.4 metres downhole yielding 0.19 and 0.83 per cent copper, 1.61 and 1.14 per cent zinc, 0.65 and 0.24 per cent lead, 55.7 and 69.7 grams per tonne silver with 1.39 and 1.64 grams per tonne gold over 0.8 and 0.5 metres, respectively (Assessment Report 20984).
Also at this time, two other nearby drillholes (RG-378 and RG-386; grid coordinates 7+65N-123+00W and 8+00N-122+00W) yielded several short higher-grade intercepts including 1.2 grams per tonne gold over 1.7 metres (71.3 to 73.0 metres downhole); 0.70 and 0.121 per cent copper, 0.84 and 0.13 per cent zinc, 0.82 and 0.07 per cent lead and 317.0 and 61.3 grams per tonne silver with 0.29 and 0.61 gram per tonne gold over 0.9 and 1.5 metres (97.3 to 98.4 and 202.6 to 204.1 metres downhole), respectively, and a broader low-grade intercept of 0.62 gram per tonne gold over 7.1 metres (40.6 to 47.7 metres downhole) in hole RG-378; and 0.50 and 0.20 per cent copper, 1.48 and 1.07 per cent zinc, 0.53 and 0.39 per cent lead and 165.6 and 92.0 grams per tonne silver with 0.64 and 0.14 gram per tonne gold over 3.0 and 0.6 metres (60.7 to 63.7 and 166.4 to 167.0 metres downhole), respectively, in hole RG-386 (Property File - Minnova Inc. [1991-07-21]: Drill Hole Records for the Sam Project Holes RG308-RG437).
In 1991, drillhole RG-401, located downslope to the southwest of hole RG-393 at an elevation of 1046 metres (grid co-ordinates 7+35N-121+00W), intercepted similar mineralization yielding 0.32 per cent copper, 0.36 per cent zinc, 0.17 per cent lead, 119.2 grams per tonne silver and 0.12 gram per tonne gold over 1.6 metres (152.8 to 154.4 metres down-hole) and 1.22 grams per tonne gold over 1.5 metres (157.4 to 158.9 metres downhole; Property File - Minnova Inc. [1991-07-21]: Drill Hole Records for the Sam Project Holes RG308-RG437). Another drillhole (RG-397), located approximately 500 metres to the northwest of hole RG-393 and near the Cana property line at 1060 metres elevation (grid co-ordinates 7+60N-126+00W), yielded 0.619 and 0.166 per cent copper, 3.07 and 0.26 per cent zinc, 1.71 and 0.32 per cent lead and 41.5 and 7.4 grams per tonne silver with 0.55 and 0.06 gram per tonne gold over 0.15 and 1.10 metres, respectively (Property File - Minnova Inc. [1991-07-21]: Drill Hole Records for the Sam Project Holes RG308-RG437).
Also at this time, drillhole RG-398 (P-7), located south of the previous drillholes at an elevation of 1050 metres (grid co-ordinates 7+90N-120+00W), intercepted zones of quartz carbonate veins with pyrite and coarse visible gold in the Samatosum sedimentary unit, referred to as the MBA Gold zone. Drilling intercepts included 40.0 grams per tonne gold over 2.1 metres (156.3 to 158.4 metres downhole), including 207.6 grams per tonne gold over 0.40 metre, 5.9 grams per tonne gold over 0.5 metre (232.9 to 233.4 metres downhole) and 5.5 grams per tonne gold over 4.9 metres (235.3 to 240.2 metres downhole), including two separate intercepts of 10.4 and 15.4 grams per tonne gold over 1.3 and 0.7 metres, respectively (Property File – Meyers, R.E. [1991-08-13]: South-Central District Monthly Reports - March and July and Hill, A. [1991-06-18]: Re: Gold intersected in Sam exploration drillhole).
Two other drillholes (RG-400 and RG-436), completed later that year to test up-dip of hole RG-398 at 1035 metres elevation (grid coordinates 6+80N-120+00W and 6+85N-119+75W, respectively) yielding intercepts of 0.62 gram per tonne gold over 9.5 metres (98.15 to 107.65 metres downhole), including 0.19 per cent copper, 2.48 per cent zinc, 2.59 per cent lead, 81.3 grams per tonne silver and 5.26 grams per tonne gold over 0.28 metre in hole RG-400 and 0.20 per cent copper, 0.90 per cent zinc, 0.57 per cent lead, 49.6 grams per tonne silver and 0.36 gram per tonne gold over 31.7 metres (149.7 to 181.4 metres downhole) in hole RG-436 (Property File - Minnova Inc. [1991-07-21]: Drill Hole Records for the Sam Project Holes RG308-RG437).
A fourth drillhole (RG-404) on the MBA zone (grid co-ordinates 8+89N-120+00W) yielded intercepts of 0.113 and 0.488 per cent copper, 0.387 and 0.840 per cent zinc, 0.226 and 1.176 per cent lead, 81.8 and 162.3 grams per tonne silver with 2.9 and 0.66 grams per tonne gold over 0.40 and 0.70 metres (206.3 to 206.7 and 291.2 to 291.5 metres downhole; Property File - Minnova Inc. [1991-07-21]: Drill Hole Records for the Sam Project Holes RG308-RG437).
Drilling on the Rea horizon to the south-southwest of the previous drillholes and at elevations of approximately 1015 to 1050 metres (grid coordinates 2+70N-115+90W and 4+40W-124+90W) yielded intercepts including 0.549 per cent copper, 0.32 per cent zinc and 14.4 grams per tonne silver over 0.80 metre (88.2 to 89.0 metres downhole) in hole RG-399 and 0.26 per cent lead with 26.3 grams per tonne silver over 3.00 metres (108.1 to 111.1 metres downhole) in hole RG-385 (Property File - Minnova Inc. [1991-07-21]: Drill Hole Records for the Sam Project Holes RG308-RG437). Another drillhole (RG-407) on the Rea horizon, located between the previous two (grid coordinates 3+65N-114+20W) intercepted a pyritic and siliceous tuff yielding 0.205 gram per tonne gold over 9.0 metres (133.9 to 142.9 metres downhole; Property File – Nagati, C. [1991-07-07]: Drill Hole Records at Samatosum - Holes RG-399, -405, -407 and -408).
Work History
The area has been explored in conjunction with the nearby Rea Gold (MINFILE 082M 191) and Samatosum (MINFILE 082M 244) occurrences and a complete exploration history can be found there.
In 1990 and 1991, Minnova Inc. completed programs of diamond drilling on the area.
