The Sonora-Nodale is located on the northwest shore of Sonora Island between Hall and Sonora points.
In the 1920s and 1930s, Sonora Gold Mines drove two short adits at sea level and a third at 300 metres elevation, and several short shafts. In 1939 and 1940, 11.79 tonnes of ore was reported mined with a grade of 891.43 grams per tonne gold (Assessment Report 21407). In 1982, Helmet Krutz staked the Argo claims on the western portion of the property. Prospecting of the old workings and geochemical surveys were conducted. J.W. McLeod also explored the property in 1984. In 1991, Cusac Industries Ltd. requested Baseline Resources Ltd. conduct an exploration program on the Bobby Burns claim group, consisting of the Daniel Webster (Lot 203A), Hetty Green (Lot 202A) and Bobby Burns (Lot 201A) Reverted Crown grants, and the Scud 1-2 claims.
In 1996, Aquistar Ventures conducted an exploration program on the area under the name of the Hope and Scud claims on the Sonora Island property, which included soil geochemical sampling, geophysical surveys and geological mapping.
The Sonora-Nodale showing is located in the 'Coastal Trough' on the western edge of the Jurassic to Cretaceous Coast Plutonic Complex, which is composed mainly of foliated and non-foliated diorite, quartz diorite and granodiorite intrusions. These intrusions host numerous elongate, steeply walled, northwest trending roof pendants, composed of greenschist to almandine-amphibolite facies metamorphosed schist, quartzite, limestone and conglomerate.
The Sonora-Nodale showing is thought to be situated near the southern extent of a major shear zone extending 25 kilometres to the northwest and following an irregular metavolcanic-intrusive contact. In places, the shear is up to 60 metres wide and hosts sulphide-bearing quartz veins within silicified alteration zones.
On the north shore of Sonora Island there are two northwest trending zones of uncorrelated Paleozoic and/or Triassic metasedimentary rock. The zones form a roof pendant that is separated and surrounded by diorite of the Coast Plutonic Complex. The pendant strikes northwest and dips 50 to 80 degrees southeast. The south zone is composed of rusty weathered quartzite, schist, aplite, greenstone and augite porphyry. The north zone is chiefly contorted marble and intercalated quartzite and schist.
Quartz veins mineralized with pyrite are found mainly in shear zones along or near the contact, in both the diorite and the metasediments. The shear zones range from less than 0.5 to greater than 20 metres wide and are generally composed of platey carbonaceous phyllite interdigitated with metavolcanics.
Quartz stringers and lenses occur in shear zones, which contain pyrite, arsenopyrite, chalcopyrite and sphalerite. Sericite alteration is common in the shears.
Thirteen grab rock samples were collected in 1991. The best sample (K3272) yielded 0.34 gram per tonne gold. The sample was taken in the vicinity of the portal of a small adit crosscutting a 0.6 to 1.0 metre wide pyritic quartz vein. Gold values are related to the pyrite which is not consistently disseminated throughout the quartz veining. High values have been reported from localized blebs and/or lenses of pyrite.
During the 1996 program, existing adits and mineralized outcrops were sampled. Assay results were not as good as those from the 1991 program. Copper values were highest in Adits #1 and #2. The soil geochemistry identified a broad northerly trending anomalous zone crossing both the metasedimentary screen and adjacent amphibolite. Geophysical work in the area outlined the igneous contacts. The conclusions of the 1996 work were: 1) The past production from the Sonora-Nodale was from the metasedimentary-igneous contact zone, and may be analogous to the Doratha Morton mine in Phillips Arm about 12 kilometres to the northwest, 2) the diorite contact is marked by geochemical and geophysical anomalies, and 3) the amphibolite/schist structural zone is marked by a broad silver anomaly.
