1. Department of Earth and Environmental Sciences; Rutgers University; Newark New Jersey USA
2. Now at Department of Geology and Planetary Science; University of Pittsburgh; Pittsburgh Pennsylvania USA
3. Department of Biological Sciences; Rutgers University; Newark New Jersey USA
4. School of Earth and Climate Sciences; University of Maine; Orono Maine USA
5. Institute for the Study of Earth, Oceans, and Space and Department of Earth Sciences; University of New Hampshire; Durham New Hampshire USA