1. Bloomsburg University of Pennsylvania, Department of Environmental, Geographical, and Geological Sciences, 400 East Second Street, Bloomsburg, Pennsylvania 17815, U.S.A.
2. University of Toronto, Department of Chemical and Physical Sciences, 3359 Mississauga Road, Mississauga, Ontario L5L 1C6, Canada
3. University of Toronto, Department of Earth Sciences, 22 Russell St., Toronto, Ontario M5S 3B1, Canada