The Shawville Intrusive Suite consists of three small calc-alkaline intrusions, granitic to granodioritic in composition, located in the southern part of the Île-du-Grand-Calumet area. The rocks are leucocratic, fine to medium grained, homogeneous in outcrops and highly foliated. Their alteration patina is light grey with a beige or pinkish tinge. The fresh fracture is pinkish grey. They are composed of quartz, K-feldspar, slightly damouritized plagioclase and minor amounts of biotite and clinopyroxene partially replaced by hornblende. Samples of granodioritic composition contain up to 5% of small plagioclase phenocrysts a few millimetres in size. Some samples are hololeucocratic and highly siliceous. The unit is characterized by a very low opaque mineral content and very weak magnetic susceptibility. Outcrops of greyish granodiorite systematically display small pink felsic bands of millimetric to centimetric thickness. These small bands are perfectly concordant with foliation, and can be distinguished from a family of small, later, subconcordant, white planar injections that have been observed in only a few outcrops.