The F 1 zone (Fall Creek) is located about 450 metres south of Fall Creek, a tributary of Todd Creek that lies approximately 15 kilometres south of the confluence of Todd Creek with the Bowser River.
The area is underlain by Hazelton Group rocks of the Lower Jurassic Unuk River Formation (Bulletin 63). Pervasively altered andesite flows and breccias are intruded by 1 to 3-metre-wide fine-grained mafic dikes. Alteration comprises chlorite-sericite-quartz-pyrite; strongly altered quartz-sericite-pyrite zones appear related to east and north-trending structures. The andesites likely trend northwest. North to northwest-trending, vertically dipping fractures, shears and faults are the most conspicuous structural elements in the area (Assessment Report 18800).
Mineralization consists of two types of veins: 1) pyrite-quartz veins, up to 1 metre wide, with 1 to 5 per cent disseminated pyrite and 2) pyrite-chalcopyrite-quartz-calcite-barite veins, up to 3 metres wide. Mineralization occurs over a 700 by 200 metre area, but the main zone of interest (to date) lies in the eastern portion of this area. Here, a zone of quartz-pyrite-chalcopyrite-barite veins and breccias occurs in a northwest striking, vertical to steeply dipping shear/fracture zone. The zone (Zone A) appears to be at least 3 metres wide and has been traced for 400 metres along strike and 300 metres vertically. Surface grab(?) samples from the zone assayed from traces of gold and copper to 24.2 grams per tonne gold and 2.24 per cent copper (Assessment Report 18800). In 2009, a chip sample (430927) from Fall Creek (south side) assayed 0.244 gram per tonne gold and 0.93 per cent copper (Assessment Report 31671).
The drilling tested the zone over a length of 100 metres and to a depth of 50 metres. The zone intersected in the drillholes is 1.25 to 11 metres wide and comprises chlorite-sericite-quartz altered andesite. The andesite contains chalcopyrite-pyrite blebs and veins and quartz-calcite-chalcopyrite-barite veins and breccias. The barite forms crosscutting features in the zone and is apparently late. The best intersection was intersected in hole NTC-88-47 which assayed 2.73 grams per tonne gold and 0.59 per cent copper across 13.0 metres (including 5.41 grams per tonne gold and 0.50 per cent copper across 5.25 metres) (Assessment Report 18800).
The induced polarization and soil surveys outlined an anomalous area, 900 metres long by 450 metres wide, which encompasses the F 1 zone and several other mineralized outcrop and float occurrences to the west.
In 1986, Noranda Exploration Limited staked the Toc 1-12 claims to cover showings in the Todd Creek area. The mineralization was discovered that year during reconnaissance prospecting near the Todd Creek (North Zone) (104A 106). From 1986 to 1989, Noranda completed geological mapping, silt and soil geochemical surveys, induced polarization and magnetometer surveys, and diamond drilling (4 holes, totalling 368 metres). Island-Arc Resources Corp optioned the property in 1997.
In 2016, Millrock Resources Inc collected total of 14 rock samples on the Todd property. Individual results range from 77 grams per tonne silver, 0.73 per cent copper, 6.24 per cent zinc from the VMS Zone (104A 185) to 9.58 grams per tonne gold and 3.68 per cent copper at the North A Zone at Fall Creek (104A 107); and, to 375 grams per tonne silver, and 0.15 per cent zinc at the Waterfall Zone (104A 102).
In 2017 stream sediment samples were collected by Millrock Resources Inc from streams that drained from the Fall Creek area. Stream sediment samples (W366405 to 407) were collected from streams draining north into Fall Creek. The Fall Creek prospect is located on one of these north-flowing tributaries to Fall Creek where 2017 sample W366407 was collected near its mouth in Fall Creek. Samples W366405 and W366406 were collected from two parallel tributaries within 400 metres to the west. All three of these samples were anomalous in gold. Sample W366407 assayed 111 parts per billion gold and 0.157 parts per million silver (Assessment Report 37268, Table 3 and Map 2a(1)).
Refer to Todd Creek-South zone (104A 001) for a detailed work history of the Todd Creek property area showings.
