The Eclipse occurrence is located on north east facing slopes, south east of Amai Inlet. The area has been explored in conjunction with the Patmore (MINFILE 092L 033) occurrence.
The region of the Eclipse occurrence is underlain by flows and pyroclastics of the Lower Jurassic Bonanza Group, intruded by granitic rocks of the Jurassic Island Plutonic Suite.
The volcanic rocks consist of massive to porphyritic, andesitic to basaltic flows that exhibit strong epidote alteration, occurring as veinlets and patches. Grey coloured aphanitic to porphyritic feldspar dacite flows and tuffs overlie the mafic rocks, and are in turn overlain by a cyclical sequence of subaerial pyroclastic felsic tuff and flows.
Medium to coarse-grained hornblende granodiorite, tonalite and minor quartz-diorite have intruded the volcanics. The contacts between the intrusive phases are mostly transitional. Contacts with the volcanics can be sharp, interpreted as fault contacts, or transitional zones, up to 130 metres wide. Post intrusive aplite and lamprophyre dikes cut both granitic and volcanic rocks.
At the Eclipse occurrence, north to northeast trending dikes and coincident fault and fracture zones cut the granodiorite rocks, and are accompanied by silicification and an alteration assemblage that includes chlorite, epidote, pyrite and biotite.
Bleaching of wallrock is common. Native gold-telluride-pyrite mineralization occurs with biotite, chlorite and quartz in a narrow central zone of intense shearing, flanked by a zone of fracturing that is up to several metres wide and locally contains some native gold in chlorite-epidote filled fractures and slip surfaces.
In 1941, a 98 kilogram test shipment yielded an average of 142.2 grams per tonne gold, 6.9 grams per tonne silver, 0.60 per cent lead and 0.03 per cent tellurium (Assessment Report 14744).
Values to 1035.87 grams per tonne and 270.89 grams per tonne gold (sample Number 2003 over 2 by 20 centimetres and sample Number 3003 over 4 by 100 centimetres respectively; Assessment Report 15153, page 8) have been obtained, but trenching suggests that the mineralized zone on surface is limited.
The "Laird zone" located 65 metres east of the Eclipse zone, has a similar geological setting. The maximum value obtained was 0.508 grams per tonne gold over 3 centimetres (Assessment Report 15153, page 10).
Anomalous values of gold have been identified in heavy sediment and rock samples from creeks over an area of up to 3.5 kilometres to the east of the occurrence (Assessment Report 15079).
The area was first prospected in 1938 and in 1940 the main Eclipse showing was discovered. In 1941 a test shipment of 98 kilograms was shipped from the Eclipse occurrence to a government sampling plant in Prince Rupert. It is unknown if the report refers to this occurrence or the nearby Patmore (MINFILE 092L 033). In 1978, a prospecting program of rock and soil sampling was completed on the area as the Amai Gold property. In 1985, Cal-Denver Resources completed a program of heavy mineral, rock and soil sampling on the area. In 1985 and 1986, Cortez Explorations completed programs of geological mapping, geochemical sampling and diamond drilling on the area. In 1987, Thomson Gold Co. Limited completed a program diamond drilling and sampling on the area as the Amai Gold property.