Outcropping along the southern shore and on islands in Bell Lake, the alkaline complex intrudes Precambrian agmatitic granites, the contacts being variously chilled, faulted or gradational. There is along the southwestern border a partial ring of pyroxenite that appears to grade into monzonites, which are the dominant rock type of the complex. The monzonites comprise approximately equal proportions of alkali feldspar and sodic plagioclase, augite, biotite, amphibole and accessories. Detailed mineralogical data are not available. All but one of a wide range of rock analyses are nepheline normative.