A Different Approach Interpreting the Geological Structures Controlling Gold at the Cabin Lake Project, NWT, CanadaThursday, November 22, 2018 - 12:00 to 12:19 Theatre 1
The Cabin Lake Project is located 110Km NW of Yellowknife (NWT). In 1945-47, a total of seven mineralized zones were discovered, 65 trenches excavated, a 340 ft. open cut was excavated in the promising No.2 zone (later referred as the Andrew Zone) and 7,406ft in a total of 38 diamond drill holes, delineating a gold mineralized zone in the northern part of the property. The southern portion of the zone averaged 0.09 oz/ton Au across 11.6 ft., including a 318 ft. strike length averaging 0.15 oz/ton across 5.8ft. (based on trenching). The northern part of the Andrew Zone returned a strike length of 400 ft., averaging 0.15 oz/ton Au across an average width of 8.7ft., at a drilled depth of 100 ft. Both these zones remained open to depth and the northern zone was also open to the south. In 1986 Aber Resources continued geological mapping, and between1986 and 1987 completed 3,174m of diamond drilling in the Bugow (Cabin Lake) leases. A new mineralized zone called the “Cabin Lake Zone” was discovered with a strike length of 100m and a depth of 70m establishing a mineral inventory of 70,000 tons grading 0.3 opt Au at the Cabin Lake zone.
The regional geology is mainly represented by two large areas or granitic intrusions of Proterozoic age, one to the north of Russell Lake and one southeast of Slemon Lake, and Russell Lake Archean belt assigned to the Archean Yellowknife Group, narrows to a 6.5km width between these two granitic batholiths and extends 70km to the north and 50km to the east of the property.
The amphibolitic iron formations are the most reliable marker beds defining the contacts of the various metagreywacke units, and are also defining areas of potential economic value. The Bugow Iron Formation is repeated several times across the property as a result of isoclinal folding. It is found as a massive unit of banded amphibolite, quartz, occasional garnet, hornblende and chlorite. Metallic minerals such as magnetite and pyrite are common in the amphibolite, with lesser amounts of pyrrhotite and arsenopyrite.
The structural interpretation done back in the day shows evidence of three phases of Archean folding. In the past, geological thinking at Cabin Lake (Bugow) has been severely limited by the lack of apparent correlation between gold values and fold hinge structures. The Andrew and Cabin Lake gold zones within the property indicate that none of them contain fold hinges. It is also demonstrated that the property shows half a dozen perfectly developed fold hinges, not one of which has responded positively to definitive prospecting, trenching, or in some cases, drilling. Clearly some other factors are involved, and that is likely bound up with the source of the gold in the property. It is also described by the geologists that worked the area that the auriferous parts of the amphibolite usually contain hornblende as opposed to the more usual grunerite. Magnetite is common in both mineralized and unmineralized amphibolite, with or without gold values.