1. Geological Survey of Canada, Vancouver, BC V6B 5J3, Canada.
2. University of Waterloo, Waterloo, ON N2L 3G1, Canada.
3. Geological Surveys Branch, New Brunswick Department of Natural Resources and Energy Development, P.O. Box 50, Bathurst, NB E2A 3Z1, Canada.
4. Geological Survey of Canada, Ottawa, ON K1A 0E8, Canada.
5. Department of Earth and Environmental Sciences, Acadia University, Wolfville, NS B4P 2R6, Canada.