Carbonatite complex, with an approximate surface of 10 km2, dated at 1 Ga.
References:
-Mariano, A. N., 1979. A petrographic examination of selected rocks and drill core from the Prairie Lake Carbonatite Complex, Ontario, Canada. Unpubl. Rep. to Union of Oil of Canada, Ltd.
-Bell, K., Blenkinsop, J., 1980. Ages and initial 87-86 ratios from alkaline complexes of Ontario. In Geoscience Research Grant Program Summary of Research, 1979-1980. Ont. Geol. Surv., MP 93: 16-23.
-Mariano, A. N., Roeder, P. L., 1989. Wöhlerite: chemical composition, cathodoluminescence and environment of crystallization. Canadian Mineralogist, 27: 709-720.