The bedrock underlying Burnt Island and portions of the East Bay of Dog Lake is typical of the lithologies commonly associated with those of the Quetico Gneiss Belt.
Investigation of this area has revealed five distinct rock units, many of which are comprised of more than one rock type. Two of these units represent metamorphic equivalents of pre-existing rocks of pelitic and basic compositions. These units have undergone polyphase deformation and metamorphism.
The first deformational episode produced folding about east-west axial surfaces and was associated with amphibolite grade metamorphism. Partial melting of the host rocks during this metamorphism gave rise to two distinctive rock units. The last of the five rock units recognized is incorporated in crystallized partial melt products as exotic blocks.
A second deformational event affected the rocks producing folds with north-south striking axial surfaces.
All rocks in this area are variably affected by a later retrogressive metamorphic event.