Geological Setting
The area is underlain by Archean mafic to felsic metavolcanic rocks, intrusions and lesser metasediments. The Archean basement is partially overlain by Proterozoic clastic metasedimentary rocks of the Huronian Supergroup. Volcanic rocks consist of intermediate to felsic volcanic rocks of the Tisdale assemblage, with local accumulations of mafic-ultramafic volcanic and intrusive rocks. Volcanic rocks exposed south of Ferris Lake represent a small window into the Archean basement where Neo-Mesoarchean Keewatin age mafic metavolcanic rocks are exposed and unconformably overlain by the Huronian cover sequence.
Structurally, the area is cut by several north-south to north-northwest trending regional scale faults cutting both the Archean and Proterozoic sequences. A prominent west-southwest trending fault passing through Lloyd Lake and into Ferris Lake could be interpreted to be the southwestern extension of the Larder Lake-Cadillac break.
