1. Lamont-Doherty Earth Observatory of Columbia University, 61 Rt. 9W, Palisades, NY 10964, USA
2. Department of Geosciences, Stony Brook University, 255 Earth and Space Sciences Building, Stony Brook, NY 11794-2100, USA
3. China University of Geosciences, Wuhan, China
4. State Key Laboratory for Mineral Deposits Research, School of Earth Sciences and Engineering, Nanjing University, 168 Xianlin Avenue, Qixia District, Nanjing 210046, China