1. Department of Earth Sciences, St. Francis Xavier University, 5009 Chapel Square, Antigonish, Nova Scotia, B2G 2W5, Canada
2. School of the Environment, Geography and Geosciences, University of Portsmouth, Portsmouth, PO1 3QL, UK
3. Hbrand Geosciences, 1401 N. Camino de Juan, Tucson, Arizona 85745, USA