1. Department of Earth and Atmospheric Sciences; University of Alberta; Edmonton Alberta Canada
2. Department of Earth and Environmental Science; Acadia University; Wolfville Nova Scotia Canada
3. Department of Earth Sciences; University of New Brunswick; Fredericton, New Brunswick Canada
4. Now at Geological Surveys Branch, New Brunswick Department of Energy and Mines; Fredericton New Brunswick Canada
5. Nova Scotia Department of Natural Resources; Halifax Nova Scotia Canada
6. Department of Marine, Earth and Atmospheric Sciences; North Carolina State University at Raleigh; Raleigh North Carolina USA