The Hanson Lake area, Saskatchewan, lies within the Churchill structural province of the Canadian Shield, about 150 mi west of the Churchill-Superior boundary. On the Tectonic Map of Canada (1969) its rocks are designated as “mainly Archaean, folded during the Kenoran and refolded during the Hudsonian (orogenies).” Detailed geological studies indicate that these ideas need some revision. The area is underlain by Kisseynew-type felsic gneisses that are overlain with no evident disconformity by Amisk-type metavolcanic and metasedimentary rocks, for which an isochron drawn on the basis of Rb/Sr isotope determination indicates an Archaean age of 2,521 ± 60 m.y. The metavolcanic rocks were intruded by four bodies of granite, for one of which a similar Rb/Sr isochron gives an Archaean age of 2,446 ± 16 m.y. The Kisseynew- and Amisk-type rocks were complexly folded during one continuous cycle of deformation, toward the end of which the granites were emplaced. The age of the granites indicates that the deformation took place during the Kenoran orogeny. The rocks were faulted and intruded by unmetamorphosed, discordant pegmatite dikes with an Rb/Sr age of 1,799 ± 2 m.y. However, there is no evidence of penetrative deformation later than the Kenoran and, therefore, no direct evidence of Hudsonian folding in the area.