The Rainbow occurrence is located on a small hill, approximately 250 metres east of Lower Ecstall Lake.

The area lies in the Middle Devonian Ecstall Greenstone Belt (Endicott Arm Assemblage), underlain by intercalated felsic and intermediate volcanics and fine clastic sediments. The Ecstall Belt is a north-northwest–trending, high-grade, metamorphic belt bounded by the elongate Middle Cretaceous Ecstall pluton on the west and the Paleocene Quottoon pluton on the east. The rocks include sericite schist, quartz sericite schist, pyritic quartz sericite schist, chlorite schist, andesite, tuff, greywacke, siltstone and argillite.

Locally, the area is underlain by interlayered felsic and intermediate metavolcanics including two units of pyritic quartz-sericite schist.

Rock sampling of the occurrence area is reported to have yielded gold values of up to 3.9 grams per tonne (Dyakowski, C. [2021-01-27]: Technical Report on the Ecstall Property, Skeena Mining Division, British Columbia).

Work History

The area has been explored in conjunction with the nearby Ecstall (MINFILE 103H 011) occurrence and a regional exploration summary can be found there.