1. Department of Geology, Colorado College, Colorado Springs, CO 80903, USA.
2. Department of Earth and Environmental Sciences, University of Minnesota, Duluth, MN 55812, USA.
3. Planetary Science Institute, Tucson, AZ 85719, USA.
4. School of Natural Sciences, Macquarie University, North Ryde, Sydney, NSW 2109, Australia.
5. Palaeoscience Research Centre, School of Environmental and Rural Science, University of New England, Armidale, NSW 2351, Australia.
6. Division of Earth Sciences, Korea Polar Research Institute, Incheon 21990, Republic of Korea.
7. Polar Science, University of Science and Technology, Daejeon 34113, Republic of Korea.
8. Department of Earth and Planetary Sciences, University of California, Riverside, CA 92521, USA.
9. Geology Department, Pomona College, Claremont, CA 91711, USA.