1. Western Michigan University, Department of Geosciences, Kalamazoo, Michigan 49008, USA
2. State University of New York at Geneseo, Department of Geological Sciences, Geneseo, New York 14454, USA
3. University of North Dakota, Energy and Environmental Research Center, Grand Forks, North Dakota 58202, USA
4. Stony Brook University, Department of Geosciences, Stony Brook, New York 11794, USA