The region is underlain mainly by rocks of the Paleozoic to Tertiary Coast Plutonic Complex. These predominantly crystalline rocks exhibit a variety of fabrics ranging from pre to post- kinematic. Paragneisses of (?)Paleozoic age, younger deformed metasediments and volcanics related to the Stikinia Terrane, are interspersed within the plutonic complex. The northeastern part of the Bella Coola map area is underlain primarily by mafic volcanic and sedimentary rocks of the Jurassic Hazelton Group. These rocks are variably deformed containing both northeast and northwest trending structures.

The Dean Channel occurrence is a magnetite skarn deposit hosted in chlorite schist within sheared diorite. Magnetite has been found in an oval area of about 85 by 30 metres with associated epidote and garnet. The magnetite ranges in style from fine-grained, almost pure, masses to being streaked and banded with quartz. In places only partial replacement of the country rock by magnetite has occurred. The chlorite schist is cut by lenses and veins of quartz.

Past production is recorded as being 1088 tonnes of magnetite, shipped in 1919 (Minister of Mines Annual Report 1919, page N86).