Eight, strong, approximately circular magnetic anomalies along the Nagagami River have in a few cases been drilled and proved to include syenitic, ijolitic and carbonatitic rocks. There is no outcrop but all the complexes are probably lying beneath a cover of Palaeozoic rocks. One drill hole on the Albany Forks occurrence passed through at least 100 m of foliated, dolomitic carbonatite with bands of magnetite and pyrochlore. Another occurrence described by Sage (1983b) and called by him the 'Nagagami River Alkalic Complex' is interpreted, from aeromagnetic data, to consist of overlapping oval complexes 12.8 and 4.8 km in diameter. Drilling indicates the principal rock types to be pyroxene-amphibole-biotite syenites, with a little quartz in some rocks and olivine in others, and amphibole-biotite-nepheline syenite.
CURRIE, K.L. 1976a. The alkaline rocks of Canada. Bulletin, Geological Survey of Canada, 239: 1-228.
FERGUSON, S.A. 1971. Columbium (niobium) deposits of Ontario. Mineral Resources Circular, Ontario Department of Mines and Northern Affairs, 14: 1-58.
SAGE, R.P. 1983b. Geology of the Nagagami River alkalic rock complex. Open File Report, Ontario Geological Survey, 5409: 1-78.